JP5339688B2 - Video projection system - Google Patents

Abstract

It is an object to provide a video projecting system that makes the picture center of a camera, which is controllable for arbitrarily setting of its height and azimuth angle, in alignment with a cursor projected from a video projector, measures a positional relationship between the video projector and a fixed star, carries out an interpolation operation or the like with reference to these values to calculate a position of the projector and its posture angle, precisely operates together with a fixed star projector, and projects a precise video. The posture of the camera is controlled so that the predetermined height and azimuth orientation on a dome are aligned with the picture center of the camera. The video projecting system makes a cursor projected from the video projector in alignment with the picture center of the video camera and measures a height and an azimuth angle of this point image and projector coordinates of the cursor at a plurality of points. A coordinate transformation is carried out on desired horizontal coordinates and a projected picture in accordance with measured data, set positions and posture angles of the projector and the like are calculated, a coordinate transformation is carried out on the basis of these values to display desired images and figures on desired horizontal coordinates.

Description

  The present invention relates to a video projector capable of projecting an image that can be arbitrarily moved on a dome screen in addition to an image such as a constellation, and a predetermined position on the screen as a coordinate on a predetermined dome screen. The present invention relates to a video projection system having imaging means that can be set as described above, and means for projecting an image projected by a video projector to a position to be originally projected.

In a conventional planetarium, an optical star projector that projects a star at the center of a dome screen is installed to project the star. An optical stellar projector can project a very sharp star image using multiple projection lenses and a stellar original plate with a precisely processed through-hole pattern, which can reproduce a very realistic and beautiful starry sky. did it.
Also, in conventional planetariums, video projectors have been used to project various astronomical objects other than stars and various images.

  For example, effects such as overlaying constellation pictures or constellation lines using a video projector on the starry sky projected by a stellar projector have been performed. Since the image generated by a video computer can be projected directly by a projection device such as a constellation picture, it is easy to change the content of the image, and the image can be moved and deformed in real time as needed, so conventional auxiliary projection It is now difficult to use the machine, and it has become possible to obtain complex and sophisticated effects such as moving the constellation through animation and linking it with a star.

However, the conventional technique has the following problems.
In order to synchronize the starry sky from the star projector and the image from the video projector, the positional relationship between the image from the star projector video projector and the star image projected from the star projector must be maintained accurately. Challenges arise. In other words, the video projector and the stellar projector are installed separately, and the projection lens is completely different, so the positional relationship of the images projected from both is complicated. After converting the position of the stellar image to coordinates on the dome screen, for example, horizon coordinates, the computer calculates the correspondence between the horizon coordinates and the coordinates on the projector screen by some method, and displays the figure based on this result. It is also necessary to project an image output by distorting the image into a necessary shape.

In order to create a function that creates the relationship between the horizon coordinates and the coordinates on the screen, the data on the correspondence between the coordinates on the screen and the horizon coordinates at a number of points in the image can be obtained in some way, or various projection-related data can be obtained. The calculation must be performed in consideration of various geometric parameters, that is, the installation position and orientation angle of the projector, and the aberration characteristics of the projector lens.
Recently, these calculations can be performed accurately in a very short time using a computer. However, it is very difficult to accurately match the installation position and attitude angle of the projector with the design values, and it is also very troublesome to measure the actually installed values of these. Further, since there may be slight errors in the construction of the dome screen, these errors affect the projection position of the image, and it is difficult to accurately project only with the above calculated values.

Patent Documents 1 and 2 disclose an example of a conventional planetarium apparatus that projects a video image and an image such as a star on a dome by a video projector and a stellar projector.
Patent Document 1 introduces a celestial body coordinate input from a telescope console into the field of view of an astronomical telescope, shoots the field of view with a video camera, and projects it onto a dome screen with a video projector. It matches the projection position by the star projector. Further, Patent Document 2 is a system for projecting onto a planetarium dome with a video projector that projects video and a projector that projects stars, etc. The image of the camera fixed to the video projector is seen, and the locus is traced on the touch panel. By tracing, the trajectory is projected onto the dome. However, the above Patent Documents 1 and 2 do not disclose means for correcting distortion of the projected image by the video projector with respect to the image by the star projector, and more specifically about the alignment of the projected images of the video projector and the projector. There is no simple structure.
JP-A-5-88610 JP-A-7-181889 JP 2006-337682 A

  From the above background, conventionally, for example, a reference mark such as an azimuth angle and altitude is projected by a laser projector or the like, or an LED or the like is installed on a dome screen, and a scale corresponding to the altitude and azimuth is projected from the projector. The process of checking and correcting the difference between the reference mark and the scale with the human eye was necessary. However, this requires labor and cost, and also requires skilled workers, which increases the installation cost of the video projector and the operating cost of the entire system. In addition, if the installation position of the projector deviates for some reason, or if the projector is replaced with a replacement device due to damage to the projector, the previous state will be completely removed due to limitations in installation work or differences in individual projectors. It is difficult to restore, and the adjustment work described above must be performed again, which may hinder stable operation of the video facility. In addition, video projectors have a shorter product update cycle than planetarium equipment, and if the projector being used is discontinued while operating the planetarium facility, it will be necessary to change to a new model number. Also, it was necessary to redo the adjustment work as described above.

Therefore, the present applicant displays a reference mark so that the coordinates on the dome screen are known, aligns this mark and an image that can be arbitrarily moved from the projector at a plurality of positions on the screen, and On the screen and a technology for converting the coordinates on the screen (Patent Document 3) have been proposed, and the above-mentioned conventional example has been greatly improved.
However, this proposal when using a laser projector for that or reference marks, placed a light emitter for the reference mark on the screen, there is a gutter cormorants problem device is complicated. In addition, when using a laser projector, the laser projector is oriented in all directions on the dome screen. Therefore, during the alignment work, to prevent the laser from entering the operator's eyes and causing injury, remove the worker from the facility. It was necessary to evacuate or to take predetermined safety measures.

The present invention has been made to solve the above problems.
An object of the present invention is to direct the orientation of a camera installed at or near the center of a screen such as a dome shape so that the coordinates on the screen are known, and from a video projector to predetermined coordinates on the camera imaging screen. Project the image (cursor) that is the mark to be displayed to match, and use the coordinates on the projector screen of the cursor at this time and the coordinates on the screen to which the camera is directed. By calculating coordinate transformation parameters and performing interpolation calculations, it is possible to reduce the labor of installation adjustment and image shift correction work, and to maintain the positional relationship with the stellar image projected from the stellar projector accurately. It can be operated at low cost, accurately projecting images, videos, figures, etc. of the desired position and shape and does not require special reference mark means. There is to provide a video projection system.

In order to achieve the above object, claim 1 of the present invention projects an image output from image generation means such as a computer or a video device onto a dome-shaped screen having a curved surface, and is arbitrarily moved on the screen. A projector capable of projecting an image as a possible mark, a camera having direction control means on the dome- shaped screen and capable of controlling the direction toward coordinates on a predetermined screen, and a position of the mark in the camera screen and align means align the predetermined coordinate, and storage means for storing on-screen coordinates facing the projected screen coordinates and the camera image to be a landmark that matches with the alignment means, stored in said storage means A coordinate conversion parameter between the coordinates on the screen and the coordinates on the projection screen using the coordinates on the projection screen of the image on the screen and the plurality of coordinates on the screen facing the selected camera. Comprising a coordinate transformation parameter calculating means for obtaining the chromatography data, and a coordinate transformation means for performing coordinate transformation from the coordinate or projection screen coordinates on the projection screen from the on-screen coordinates to a screen on the coordinates using the coordinate transformation parameter, wherein The alignment means extracts a position of an image serving as a mark from a photographed image of the camera, and an image position serving as a mark output from the projector so that the image position serving as the mark matches a predetermined position on the camera screen And control means for controlling .
According to a second aspect of the present invention, an image output from image generation means such as a computer or a video device is projected onto a dome-shaped screen having a curved surface, and an image that can be arbitrarily moved on the screen is formed. A projector capable of projecting, a camera provided with direction control means capable of controlling the direction toward the coordinates on the predetermined screen on the dome-shaped screen, and the position of the mark in the camera screen are aligned with the predetermined coordinates. Positioning means; storage means for storing coordinates on the projection screen of the image that is the mark matched by the positioning means; coordinates on the screen facing the camera; and a plurality of screens facing the camera stored in the storage means Using the coordinates on the projection screen and the coordinates on the projection screen, the coordinate transformation parameters for obtaining the coordinate transformation parameters between the coordinates on the screen and the coordinates on the projection screen are used. Meter calculation means, and coordinate conversion means for performing coordinate conversion from the coordinates on the screen to the coordinates on the projection screen or the coordinates on the projection screen to the coordinates on the screen using the coordinate conversion parameters, the positioning means An operation device is provided that can manually move an image to be a mark on a projection screen, and the image to be a mark is adjusted to a predetermined position on the camera screen by the operation device.
According to a third aspect of the present invention, an image output from image generation means such as a computer or a video device is projected onto a dome-shaped screen having a curved surface, and an image serving as a mark that can be arbitrarily moved on the screen. A projector capable of projecting, a camera provided with direction control means capable of controlling the direction toward the coordinates on the predetermined screen on the dome-shaped screen, and the position of the mark in the camera screen are aligned with the predetermined coordinates. Positioning means; storage means for storing coordinates on the projection screen of the image that is the mark matched by the positioning means; coordinates on the screen facing the camera; and a plurality of screens facing the camera stored in the storage means Using the coordinates on the projection screen and the coordinates on the projection screen, the coordinate transformation parameters for obtaining the coordinate transformation parameters between the coordinates on the screen and the coordinates on the projection screen are used. Meter calculation means, and coordinate conversion means for performing coordinate conversion from the coordinates on the screen to the coordinates on the projection screen or the coordinates on the projection screen to the coordinates on the screen using the coordinate conversion parameters, the positioning means A control unit that extracts a position of an image serving as a mark from a captured image of the camera, and controls a direction in which the camera is directed so that the image position serving as the mark matches a predetermined position on the camera screen; The camera is mounted on a stellar projector, and the means for changing the direction of the camera uses angular position control means of the rotation axis of the stellar projector.
According to a fourth aspect of the present invention, an image output from image generation means such as a computer or a video device is projected onto a dome-shaped screen having a curved surface, and an image serving as a mark that can be arbitrarily moved on the screen. A projector capable of projecting, a camera provided with direction control means capable of controlling the direction toward the coordinates on the predetermined screen on the dome-shaped screen, and the position of the mark in the camera screen are aligned with the predetermined coordinates. Positioning means; storage means for storing coordinates on the projection screen of the image that is the mark matched by the positioning means; coordinates on the screen facing the camera; and a plurality of screens facing the camera stored in the storage means Using the coordinates on the projection screen and the coordinates on the projection screen, the coordinate transformation parameters for obtaining the coordinate transformation parameters between the coordinates on the screen and the coordinates on the projection screen are used. Meter calculation means, and coordinate conversion means for performing coordinate conversion from coordinates on the screen to coordinates on the projection screen or from coordinates on the projection screen to coordinates on the screen using the coordinate conversion parameters, and the alignment means includes a camera An operation device capable of manually moving the direction of the image, and aligning a predetermined position on the camera screen with an image serving as a mark by the operation device. The camera is mounted on a stellar projector and changes the direction of the camera. The means is characterized by using angular position control means of the rotation axis of the stellar projector.
According to a fifth aspect of the present invention, in the first, second, third, or fourth aspect , the coordinate conversion parameter includes a position where the projector is installed, a posture angle, a focal length of the projection lens, or any combination thereof. It is characterized by being.
According to a sixth aspect of the present invention, an image output from image generation means such as a computer or a video device is projected onto a dome-shaped screen having a curved surface, and an image serving as a mark that can be arbitrarily moved on the screen. and projectable projector, wherein on the dome-shaped screen, predetermined and camera to be directed orientation toward the coordinates on the screen, position if Wasesuru the placemark on a given coordinate in the screen of the camera and align means, storage means for storing the projection screen coordinates and dome screen on the coordinate pointing the camera of the image serves as a mark matched by said alignment means, a plurality of facing the camera stored in the storage means Using the coordinates on the screen and the coordinates on the projection screen of the image that serves as a mark, the coordinate transformation between the coordinates on the screen and the projected screen coordinates at any position on the screen And a interpolation operation means for performing said alignment means extracts the position of the image which serves as a mark from the captured image of the camera, the projector so as to match the predetermined position of the image position and the camera on the screen as the landmark And a control means for controlling an image position serving as a mark output from the control unit .
According to a seventh aspect of the present invention, an image output from image generation means such as a computer or a video device is projected onto a dome-shaped screen having a curved surface, and an image serving as a mark that can be arbitrarily moved on the screen. A projector capable of projecting, a camera on the dome-shaped screen that can be directed toward the coordinates on the predetermined screen, and a position for aligning the position of the mark in the camera screen with the predetermined coordinates Alignment means, storage means for storing the coordinates on the projection screen of the image that is the mark matched by the alignment means, and coordinates on the dome screen facing the camera, and a plurality of screens facing the camera stored in the storage means Using the coordinates and coordinates on the projected image of the image to be a mark, coordinate conversion between the on-screen coordinates and the projected screen coordinates at any position on the screen Interpolation means for performing the operation, and the positioning means has an operation device capable of manually moving the image serving as the mark in the projection screen, and the image serving as the mark by the operation device is moved to a predetermined position on the camera screen. It is characterized by matching.
According to an eighth aspect of the present invention, an image output from image generation means such as a computer or a video device is projected onto a dome-shaped screen having a curved surface, and an image that can be arbitrarily moved on the screen is formed. A projector capable of projecting, a camera on the dome-shaped screen that can be directed toward the coordinates on the predetermined screen, and a position for aligning the position of the mark in the camera screen with the predetermined coordinates Alignment means, storage means for storing the coordinates on the projection screen of the image that is the mark matched by the alignment means, and coordinates on the dome screen facing the camera, and a plurality of screens facing the camera stored in the storage means Using the coordinates and coordinates on the projected image of the image to be a mark, coordinate conversion between the on-screen coordinates and the projected screen coordinates at any position on the screen Interpolating means for performing extraction, and the positioning means extracts a position of an image serving as a mark from a photographed image of the camera, and the camera position so that the image position serving as the mark matches a predetermined position on the camera screen The camera is mounted on a stellar projector, and the means for changing the direction of the camera uses angular position control means of the rotation axis of the stellar projector. Features.
According to a ninth aspect of the present invention, an image output from image generation means such as a computer or a video device is projected onto a dome-shaped screen having a curved surface, and an image that can be arbitrarily moved on the screen is formed. A projector capable of projecting, a camera on the dome-shaped screen that can be directed toward the coordinates on the predetermined screen, and a position for aligning the position of the mark in the camera screen with the predetermined coordinates Alignment means, storage means for storing the coordinates on the projection screen of the image that is the mark matched by the alignment means, and coordinates on the dome screen facing the camera, and a plurality of screens facing the camera stored in the storage means Using the coordinates and coordinates on the projected image of the image to be a mark, coordinate conversion between the on-screen coordinates and the projected screen coordinates at any position on the screen Interpolation operation means for performing, the positioning means has an operating device that can manually move the direction of the camera, and aligns a predetermined position on the camera screen with an image serving as a mark by the operating device, The camera is mounted on a stellar projector, and the means for changing the direction of the camera uses angular position control means of the rotation axis of the stellar projector.
According to a tenth aspect of the present invention, in the first, second, sixth or seventh aspect , the camera is mounted on a stellar projector, and the means for changing the direction of the camera is a rotation axis of the stellar projector. An angular position control means is used.
According to an eleventh aspect of the present invention, in the invention according to the first, second, third , fourth, fifth , sixth, seventh , eighth, ninth, or tenth aspect , the coordinates on the dome screen directed by the camera are altitude and azimuth. It is characterized by being represented as horizontal coordinates.

  According to the above configuration, it is possible to easily and accurately correct the deviation of the projected image of the video projector with respect to the projected image of a star or the like projected onto the dome screen. Simplification of installation work and cost reduction can be achieved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, the relationship between the coordinates on the projection screen and the coordinates on the hemispherical dome screen when a video projector is installed in the planetarium dome facility will be described.
The video projector projects the video (projection screen) output from the video generation device almost as it is. If the screen is a plane and is orthogonal to the optical axis of the video projector, the projected screen is projected on the screen surface as it is.
However, in the case of a dome screen, since the screen surface is a curved surface, a complicated distortion occurs in the projected image. Therefore, it is necessary to distinguish the coordinates on the projection screen from the coordinates on the dome screen.

1A to 1F are diagrams for explaining the relationship between the coordinates on the dome screen and the coordinates on the projection screen. Here, the coordinates on the dome screen are horizon coordinates expressed by altitude and azimuth with respect to the center of the dome.
FIG. 1A is a diagram showing horizon coordinates on a dome screen.
FIG. 1B shows a projection screen projected by this video projector. The coordinates on the projection screen are represented by two-dimensional orthogonal coordinates represented by X and Y. The width is W and the height is H.
FIG. 1C is a perspective view showing a state in which the projection screen shown in FIG. 1B is projected by a video projector installed in the dome screen. The video projector 3 projects an image 6 on the dome screen 1. A coordinate line 6a on the image 6 is a coordinate line on the projection screen indicated by a broken line in FIG. 1B.
FIG. 1D is an example of a projection screen for correctly projecting the horizon coordinate line on the dome. Since it is projected onto the spherical surface, complicated distortion occurs, and it can be seen that the horizon coordinate line draws a complex curve on the screen.

For example, when the orientation of the projector is shifted twice, the image example shown in FIG. 1E is obtained. If attention is paid to the vicinity of the zenith in the image example of the correct setting, it can be seen that the image near the zenith is slightly shifted downward. Furthermore, when the focal length of the lens is shortened, the image example shown in FIG. 1F is obtained. It can be seen that the degree of curving of the video differs when compared with a video example with the correct setting. In other words, the shape is a deformed shape from the original image shape.
In the present invention, the position and orientation of the video projector is obtained and the coordinates on the dome screen are converted from the coordinates on the screen so as to minimize the above-mentioned image distortion, and the image or figure is projected to the correct position. Is.

First, before describing the embodiment of the present invention, the specific calculation content of the basic coordinate transformation of the projector will be described.
Here, it is calculated which coordinate on the projection screen of the projector corresponds to a known point of altitude and direction on the dome screen.
Cartesian coordinates with the origin of the dome as the origin, the X axis as the south, the Y axis as the west, the world coordinate as the Cartesian coordinate system with the Z axis as the zenith, and the projector position (lens aperture position) as the origin and the coordinate axis direction as the world coordinate An orthogonal coordinate system in which the system is a local coordinate, the projector position is an origin, the front is X, the side is Y, and the upper is Z with respect to the bottom of the projector is a projection coordinate.

Let f be the focal length of the projection lens of the projector, and R be the dome radius.
The video camera captures an object on the optical axis at the center of the screen.
By the servo control of the stellar projector, the direction of the video camera is oriented so that the screen center of the video camera is the horizontal coordinate (AZM, ALT) (azimuth = AZM, altitude = ALT).
Display the cursor so that it overlaps. The coordinates of the cursor on the projector screen at this time are (CX, CY).
Now, the actual values of the projector settings (position and attitude angle) are unknown, but this value is the world coordinate, for example, (PX, PY, PZ) as the design value, and the attitude angle (p, y, Assume r). The world coordinates of the projected cursor image are
WX = R ・ cosAZM ・ cosALT
WY = R ・ sinAZM ・ cosALT
WZ = R ・ sinALT
It becomes. Convert this to local coordinates,
LX = WX-PX
LY = WY-PY
LZ = WZ-PZ
It becomes.

プロジェクタのパネル（画面）上の推定座標は
CPX ＝PYR/PXR
CPY ＝PZR/PXR
となる。
この計算例では、地平座標から投影画面上座標への変換例を示したが、もちろん逆の計算で、投影画面上座標から地平座標への変換も可能である。 To convert this to projection coordinates

The estimated coordinates on the projector panel (screen) are
CPX = PYR / PXR
CPY = PZR / PXR
It becomes.
In this calculation example, an example of conversion from the horizontal coordinate to the coordinate on the projection screen is shown, but it is of course possible to convert from the coordinate on the projection screen to the horizontal coordinate by reverse calculation.

FIG. 2 is a side view of a dome theater equipped with a video projection system according to the present invention, and FIG. 3A is a diagram for explaining an embodiment of a star projector used in the video projection system according to the present invention. A stellar projector 2 having a number of projection units for projecting a star on the dome screen 1 has three rotation axes, a diurnal axis 2a, a latitudinal axis 2b, and an azimuth axis 2c. Any angular position can be set. By a driving source pedestal 12 (not shown) for receiving the support frame 11 and support frame 11 for supporting the fixed star projector 2, its Re respectively diurnal axis 2a, it can be adjusted latitude shaft 2b and azimuthal axis 2c, the computer 7 It is driven by the command.
The video camera 57 is installed on the latitude axis base of the stellar projector 2 in such a posture that the optical axis of the camera passes through the center of the stellar projector, that is, the intersection of the diurnal axis and the latitude axis, and is orthogonal to both the diurnal axis and the latitude axis. Has been.
The intersection of the straight line perpendicular to both the latitude axis and the diurnal axis from the center of the star projector and the dome screen is called the altitude bearing point of the star projector.

The position of the point where the optical axis of the video camera 57 intersects the dome screen 1, that is, the point reflected at the center of the camera screen is determined on the dome screen 1 by the angle between the diurnal axis 2a and the azimuth axis 2c of the stellar projector 2. It can be set at any position. The center of the star projector 2 coincides with the spherical core of the dome screen 1, and the optical axis of the video camera 57 accurately intersects the diurnal axis 2a, the latitude axis 2b, and the azimuth axis 2c of the star projector 2, and the latitude If the axis 2b and the diurnal axis 2a are exactly perpendicular to the plane, the azimuth angle and altitude on the dome screen reflected in the center of the camera screen are respectively the azimuth angle indicated by the azimuth axis 2c and the latitude axis 2b. It becomes equal to the latitude angle shown.
Thereby, the star projector 2 has a function of setting the center position of the video camera screen at an arbitrary altitude and azimuth angle position on the dome screen 1 by controlling the angular positions of the latitude axis 2b and the azimuth axis 2c. Will have.
FIG. 5 shows an example of a point that becomes the center of the screen of the video camera, that is, an altitude azimuth point of a stellar projector.

The video projector 3 is configured to project a screen generated from the computer 7, and the content of the screen is projected onto the dome screen 1 as a video a. The attitude angle of this video projector is represented by the angle of each axis of pitch (p), yaw (y), and roll (r) as shown in FIG. 4, and the coordinates of the position of the video projector are represented by X as shown in FIG. , Y, and Z points (Px, Py, Pz).
The computer 7 controls display of a cursor that can be moved to an arbitrary position by an operation of a mouse or the like by an operator, and the cursor image 4 is projected onto the dome screen 1.

  When the azimuth axis 2c and latitude axis 2b of the stellar projector 2 are set to certain predetermined values, the position reflected in the center of the video camera screen is naturally the predetermined value of azimuth and altitude (represented as AZM and ALT). However, when this position is within the range of the image a, the operator moves the cursor by operating the mouse or the like, and the cursor image projected by the video projector 3 is set at the center position of the screen imaged by the video camera. Match. The coordinates of the cursor at this time are recorded as data on the computer 7, and the coordinates are X and Y.

The operator manually inputs the altitude and azimuth set at the center of the video camera screen, which is known in advance, or acquires the altitude and azimuth directly from the star projector 2 using appropriate communication means and control means. By acquiring the value of the mouse cursor at that time, for example, the relationship between the X1, Y1 coordinate values on the projection screen (screen projected by the projector), the actual azimuth angle on the dome, and the altitude value is expressed as (X1, Y1 ) & (AZM1, ALT1). The computer 7 can store this value. Hereinafter, the pair of (X1, Y1) and (AZM1, ALT1) is referred to as a horizon & screen coordinate pair.
This operation is repeated many times by changing the azimuth angle and latitude angle of the stellar projector, thereby creating a set of horizon & screen coordinate pairs of the relationship (Xn, Yn) & (AZMn, ALTn) (n = 1, 2, ...).

By creating this relationship over a wide range of screens, the relationship between the actual altitude and azimuth on the computer screen can be illustrated, and by complementing this value, on the screen for any altitude and azimuth. It is possible to create a complementary expression for obtaining an approximate expression of the coordinates of.
Therefore, for example, when it is desired to project a celestial object at an azimuth angle and altitude of (Azmp, Altp), the altitude and azimuth are converted into (Xp, Yp) of the XY coordinates based on this complementary formula, and the celestial object is located at the XY coordinate position. Can project a celestial image at a desired azimuth and altitude position. The accuracy of the projection position becomes more accurate as the number of related data on the screen is larger and the interval is closer.
Since data sampling is time consuming, in order to obtain a better correction result with the minimum number of data samples, the projector position, orientation angle, and optical characteristics are not simply complemented with coordinate values. Thus, the method of converting the azimuth angle on the dome screen from the screen to the high altitude is close to the theoretical value and is preferable.
Therefore, the actual position and orientation angle of the projector, the optical characteristics of the projector, and the like are estimated using the sample values, and coordinate conversion is performed based on these values. This is a very good coordinate transformation.

  The example of FIG. 3A shows an example in which the video camera 57 is incorporated in the stellar projector 2 as the direction control means of the video camera, but the video camera 57 is independent of the stellar projector 2 as shown in FIG. 3B. The camera control unit is set in the dome and is set to a predetermined altitude and azimuth angle on the dome screen by the direction control means installed independently of the stellar projector 2. It is also possible. The direction control means includes an azimuth turntable 75 that is installed on a base 76 fixed on the ground so as to be rotatable around an azimuth axis 72, and an azimuth axis motor 73 capable of controlling the rotation angle of the azimuth turntable 75. The video camera 57 is driven and controlled at a predetermined azimuth angle by these configurations. Further, a support column 77 planted on the azimuth turntable 75, a rotation device 78 of the altitude shaft 70 rotatably attached to the tip end of the support column 77, and an altitude shaft motor 74 that rotationally drives the rotation device 78 are provided. The video camera 57 attached to the rotating device 78 is driven and controlled to a predetermined altitude by the altitude axis motor 74. Thereby, the optical axis 71 of the video camera can be set to a predetermined azimuth and altitude.

  If the above camera unit is installed at the center of the dome screen, the altitude and azimuth angle of the camera unit will be the center of the camera screen as it is, but this is convenient. Need to move. Therefore, the stellar projector may be provided with an elevator raising / lowering mechanism and lowered from the center, or a horizontal slide mechanism may be provided and shifted horizontally. In addition, even if the stellar projector is installed and the camera unit is installed at a position shifted from the center of the dome, the center of the video camera screen can be set to the desired altitude and azimuth on the dome screen by correction control. Is possible.

FIG. 3C is a diagram for explaining an example of a correction control method when the camera unit is installed at a position shifted from the center of the dome.
Assume that the radius of the dome screen 42 is R, and the camera unit 81 is installed at a position away from the center of the dome screen 42 by PX, PY, PZ in orthogonal coordinates.
In order to set the point of the azimuth AZM and altitude ALT on the dome screen 42 as the center point of the camera screen, the following may be performed.
First, the orthogonal coordinates (XP1, YP1, ZP1) of the point 80 to be the center of the camera screen on the dome screen 42 are obtained.
XP1 = cos (AZM) * cos (ALT) * R
YP1 = sin (AZM) * cos (ALT) * R
ZP1 = sin (ALT) * R

Subsequently, the coordinates (XP2, YP2, ZP3) are converted with reference to the camera unit 81 using the equations (1) to (3).
XP2 = XP1-px (1)
YP2 = YP1-py (2)
ZP2 = ZP1-pz (3)
Furthermore, it is converted into polar coordinates (AZM1, ALT1) using equations (4) and (5).
AZM1 = atan (YP2 / XP2) (4)
ALT1 = atan (ZP2 / sqr (XP2 * XP2 + YP2 * YP2) (5)
Note that “sqr” shown in the formula represents a square root.
If the azimuth axis and altitude axis of the camera unit 81 are set to the angles of AZM1 and ALT1, respectively, the camera screen center point can be set to the positions of the azimuth angles AZM and altitude ALT viewed from the dome center position.

FIG. 7 is a block diagram showing an embodiment of an apparatus for aligning the cursor of the video projection system and the screen center position of the video camera according to the present invention, and shows the configuration of a part of a computer that manually aligns the cursor. is there.
The horizon coordinate setting device 35 sets a predetermined azimuth angle and altitude (azm, alt) for the center position of the video camera screen. For example, a plurality of azimuth angles and altitudes are set in advance. Are output to the servo control device 36 and stored in the horizontal coordinate one-screen coordinate correspondence data storage device 39. The timing control at which this data is output from the servo controller 36 is performed manually, or it is detected that the cursor image 56 is aligned with the center position of the video camera screen of the azimuth angle and altitude output immediately before. And you can do it automatically. The servo control device 36 includes a transmission mechanism (a reduction gear group, a drive shaft conversion gear, a belt, etc.) that transmits the rotational driving force of a driving means such as a motor to the azimuth axis and the latitude axis of a star projector 37 with a built-in video camera. Thus, the azimuth and latitude axes of the star projector 37 can be driven and adjusted so that the azimuth and altitude given from the horizon coordinate setting device 35 are the same. The central position 61 of the video camera screen of the dome screen 42 is projected at the set azimuth angle and altitude of the star projector 37.

The video camera 57 captures an image with a predetermined number of pixels, for example, the horizontal pixel number is CW and the vertical pixel number is CH. The screen center of the video camera 57 is the coordinates on the screen of the video camera 57 (CW / 2, CH / 2). The output of the video camera 57 built in the stellar projector 37 is connected to a video screen display monitor 82, and a screen shot by the video camera 57 can be displayed. The cursor coordinate setting device 31 is a device for setting the coordinates of the cursor. The operator can move the cursor to a predetermined position on the screen by operating the cursor position operating device 30 such as a mouse. The cursor coordinate setting device 31 recognizes the moved cursor position and displays the coordinate position of the cursor on the cursor display device 32 such as a liquid crystal display unit. A cursor is projected onto the dome screen 42 by the video projector 33, and the position is the coordinate position displayed on the cursor display device 32.
The operator operates the position of the cursor so that the cursor appears on the video screen while watching the video screen monitor 82, and further operates so that the cursor matches the center of the video screen. At this time, in order to know the center of the video screen, a means for overlaying and displaying the center position on the video screen is provided, or simply, a transparent film or the like is pasted on the video screen display monitor 82, The screen center position corresponding to (CW / 2, CH / 2) may be written with magic ink or the like.

The cursor coordinates are stored in the horizontal coordinate-screen coordinate correspondence data storage device 39 in association with the horizontal coordinate (azmn, altn) of the center of the screen of the video camera 57 that has been aligned. Thus, the operator can visually match the cursor to the screen center of the video camera 57 and store the position with respect to the screen center position of the video camera whose azimuth and altitude can be changed in order.
Note that the cursor can be positioned by operating a direction key such as a keyboard or a cross key such as a pad instead of a mouse.
In addition to fixing the stellar projector 37, that is, the video camera 57 and aligning the cursor so that it matches the center of the screen of the video camera 57, the cursor is fixed at a predetermined coordinate and displayed. The position of the center of the video camera 37 on the dome screen 42 is moved by the rotation angle position control of the diurnal axis and the latitude axis of the stellar projector 37, and the screen center of the video camera 57 is aligned with the cursor. Good.

  Thus, using the data stored in the horizontal coordinate-screen coordinate correspondence data storage device 39, the parameter calculation device 40 can determine the projector parameters (coordinates, posture angle, lens focal length) that realize the minimum image distortion. The projector parameters obtained as described above are expressed as true projector parameters.

FIG. 8 is a block diagram showing another embodiment of an apparatus for aligning the cursor of a video projection system and the center of a video camera screen according to the present invention. A cursor image is obtained by electronically processing a screen imaged by a video camera. An example of automatically aligning with the center of the video camera screen is shown.
The cursor display device 32, the video projector 33, the horizon coordinate setting device 35, the servo control device 36, the stellar projector 37, and the parameter calculation device 40 are the same as the devices given the same reference numerals in FIG.
The cursor coordinate setting device 53 is a device for setting the coordinates of the cursor, and based on the error data input from the differential computing unit 52, the screen center position 61 of the video camera with respect to the cursor coordinates output to the video projector 33. And the cursor coordinates so that there is no error in the position of the cursor image 56 is controlled. The cursor coordinates output from the cursor coordinate setting device 53 are displayed on the cursor display device 32. A cursor is projected onto the dome screen 63 by the video projector 33, and the position thereof is the coordinate position displayed on the cursor display device 32.

  The video camera 57 captures the cursor image 56 projected on the dome screen 63, and the analog image is converted into a predetermined image data format (image data) by the video capture unit 50. The image processing device 51 analyzes the input image data, recognizes the cursor image 56 based on the feature shape, obtains the address data, and calculates the XY coordinates of the cursor based on the address data.

  At this time, various methods are conceivable for the algorithm for recognizing the cursor image. For example, the cursor can be turned on / off, the image is taken with the cursor turned on, and the image is stored (image A). If an image (image B) taken with the cursor turned off is prepared, and an image (image C) in which the luminance difference of each pixel is taken between the two images is created, in image C, the other other subjects are Since it is canceled out and only the cursor image part emerges, the cursor image can be easily recognized. Both the XY coordinate data of the cursor recognized in this way and the data of the coordinates (CW / 2, CH / 2) of the screen center of the video camera are input to the − and + input terminals of the differential calculator 52. Then, error data is output from the differential calculator 52 and input to the cursor coordinate setting device 53.

If there is no error and the output of the differential calculator 52 is zero, the cursor coordinate setting device 53 assumes that the cursor coincides with the center of the video camera screen, and stores the cursor coordinate in the horizontal coordinate-screen coordinate correspondence data storage device 62. Remember. The horizon coordinate-screen coordinate correspondence data storage device 62 stores the cursor coordinates in association with the horizon coordinates (azmn, altn) at the center of the video camera screen where the alignment has been performed.
If there is an error, the cursor coordinates corrected for the error are output from the cursor coordinate setting device 53, and an image similar to the above is taken in and calculated so that the cursor image coincides with the center of the video camera screen. Matching control is performed.

FIG. 14 is a schematic diagram showing an embodiment of the video projection system of FIG.
The video camera 57 is juxtaposed to the stellar projector 37, takes a cursor image projected on the dome screen by the video projector 33, the output is connected to a computer (not shown), and the cursor image is centered on the screen of the video camera. The coordinate position of the cursor image is automatically adjusted to match.

FIG. 15 is a perspective view showing an embodiment of a video projector installation structure.
The pedestal 58 is configured to be rotatable about the vertical direction. The vertical axis is a yaw (y) axis, and the yaw angle can be adjusted. A support column 59 is planted on the upper surface of the pedestal 58, and a support rod 60 is attached to the tip end of the support column 59 so as to be rotatable about the horizontal direction. This horizontal axis is the pitch (p) axis, and the pitch angle can be adjusted. A support frame 63 is attached to the upper end of the support rod 60 so that the video projector 33 can rotate around an axis parallel to the optical axis direction of the video projector 33. The axis parallel to the optical axis direction is the roll (r) axis, and the roll angle can be adjusted.
The attitude angle of the video projector can be adjusted by adjusting the yaw angle, pitch angle and roll angle. By setting the true projector coordinates and attitude angles determined by the parameter calculation device, it is possible to project an image from a projector with the least image distortion on an individual planetarium dome screen.

Next, an embodiment in which coordinate conversion parameters are calculated using a cursor and coordinate conversion will be described.
On the premise that the curvature radius of the dome and the focal length of the projection lens of the video projector are known in advance, the video projector is mounted at a position and posture close to the designed position and posture, for example, and the screen is projected onto the dome screen. This combination of projector position and attitude angle is hereinafter referred to as a projector parameter.

Orient the video camera so that its screen center is at a predetermined azimuth and altitude (azm1, alt1). Then, the cursor on the projector screen is matched with the center of the video camera screen. The point at this time is point 1, and the cursor coordinates (CX1, CY1) and (azm1, alt1) on the screen are collectively called a horizon & screen coordinate pair and stored in the computer. If this operation is repeated n times to the point n,
(CX1, CY1) & (azm1, alt1)
(CX2, CY2) & (azm2, alt2)
:
:
(Cxn, CYn) & (azmn, altn)
A data string of the horizon & screen coordinate pair is stored in the storage device 39 (62) of the computer.

Assuming that the projector position (x, y, z) and attitude angle (p, y, r) are certain values (for example, design values) (provisional projector parameters), the horizontal coordinates (azm1, alt1) Calculate where the points correspond on the projector screen. Let the calculated value be (CPX1, CPY1). This value is assumed to be an estimated coordinate on the projection screen.
Here, if the temporary projector parameters completely match the actual projector installation position and attitude angle, the estimated coordinates (CPX1, CPY1) are the coordinates on the screen (CX1, CPY1) extracted from the horizon & screen coordinate pair. Should match CY1). However, if there is an actual error, a difference due to the error occurs in both coordinates. The coordinate value error Err is
Err = ((CPX1−CX1) 2 + (CPY1−CY1) 2) 1/2 (6)
become.

This is performed at a plurality of points, and the same calculation is performed on a plurality of horizon & screen coordinate pairs to obtain a sum ΣErr of each coordinate value error. If the temporary projector parameter matches the actual set value, ΣErr is still 0, but in reality, it becomes a value corresponding to the error.
FIG. 9 shows an embodiment of an error sum calculation apparatus for obtaining ΣErr.
In FIG. 9, the error sum calculation device is composed of coordinate conversion devices (1) 65a to (n) 65n, screen coordinate error calculation devices (1) 66a to (n) 66n, and an accumulation device 67.
Coordinate converters (1) 65a to (n) 65n take projector parameters for the horizontal coordinates (azm1, alt1) to (azmn, altn) and convert them into estimated coordinates (CPX1, CPY1) to (CPXn, CPYn), respectively. To do. The screen coordinate error calculation device (1) 66a to (n) 66n adopts the estimated coordinates (CPX1, CPY1) to (CPXn, CPYn) for the coordinates (CX1, CY1) to (CXn, CYn) on the screen, respectively. The calculation of 6) is performed to calculate the coordinate value errors Err1 to n. The integrating device 67 integrates the coordinate value errors Err1 to n and outputs the sum of errors.

Therefore, conversely, if a projector parameter in which ΣErr is 0 can be found, it can be said that this is a true set value. In reality, there are measurement errors and so on, so there are very few conditions for ΣErr to be completely zero, but it is only necessary to find the projector parameter (optimum projector parameter) that makes ΣErr closest to zero.
There are various methods for determining the optimum projector parameter. For example, the simplest method is to search for a condition for obtaining the minimum value by obtaining ΣErr by changing the projector parameter in various ways with a value close to the design value. is there.
Projector parameters that ultimately use this position and attitude angle are adopted as coordinate transformation parameters, and the projector coordinate transformation is performed, and if the coordinates on the projector are calculated from the altitude and azimuth to be displayed, the image is always in the correct position. Can be displayed.

Next, a procedure for projecting the master image drawn on the basis of the horizontal coordinate using the coordinate transformation parameters so as to be correctly projected by the coordinate transformation will be described.
Here, in order to explain the master image, an example of the master image is shown in FIG.
The master image is a digital image composed of a predetermined number of pixels in the vertical and horizontal directions, and is stored in a master image memory (not shown) in the computer. As shown in the figure, the horizontal axis corresponds to the azimuth angle in the horizontal coordinate and the vertical axis corresponds to the altitude. The horizontal width is w pixels, the height is h pixels, and the resolution of an image for setting an angle corresponding to one pixel is RESO pixel / degree. In other words, for example, the horizontal coordinate (azmg, altg) of a pixel (gx, gy) in the image is
azmg = gx * RESO
altg = gy * RESO
It becomes.
From the master image memory, color information of a pixel at an arbitrary position can be extracted.

FIG. 11 is a flowchart showing a procedure for transforming the master image and drawing it on the projection screen.
When the program starts (step (hereinafter referred to as “S”) 01), the program performs processing on all pixels on the screen, so the coordinates GX on the master screen are changed from 0 to W, and GY is changed from 0 to H. Until one is changed. The execution of this loop operation is S02 and S03.
Then, the color information of each pixel set in the loop is read and substituted into the variable Col (S04). Further, the horizontal coordinate of this pixel is calculated from the coordinates GX and GY on the master screen and substituted for the azimuth angle azmg and the altitude altg (S05). The azmg and altg are converted into the coordinates on the screen of the projector by the coordinate conversion means, and these are set as CX and CY (S06). Subsequently, the point of the color acquired in S04 is drawn at the point of coordinates CX, CY on the projector screen (S07). By performing this for all pixels, an image for projecting the image at the correct position on the dome screen appears on the projector screen. S08 and S09 are the end of the loop of GX and GY.

FIG. 12 shows how the master image is deformed and projected correctly by such a procedure. FIG. 12A is a master image, and the coordinate lines are horizon coordinates (azimuth, altitude). FIG. 12B shows a state in which the master image is coordinate-transformed and drawn on the projection screen. For easy understanding, FIG. 12 shows coordinate lines that are not actually projected onto the dome screen. FIG. 12C is a perspective view of the projection screen projected by the projector. You can see how it is projected correctly along the horizontal coordinate scale on the dome.
In this embodiment, an example of drawing by converting to coordinates on the projector screen based on the coordinates of the original image is shown, but in actuality, the values of CX and CY are changed on the coordinates on the projector screen. And reverse conversion processing to convert from the XY coordinates to the horizon coordinates, find the coordinates GX, GY in the original image, and then read out the pixel color of the coordinates (GX, GY) of the original image on the screen Of course, it is possible to draw at the coordinates (CX, CY).

Next, a procedure for projecting a figure onto the dome screen by this coordinate conversion procedure will be described.
This embodiment is an example of drawing a line segment as an example of the simplest graphic. Drawing a line segment is a technique that is useful, for example, when connecting stars constituting a constellation with straight lines.
The feature points of the line segment are end points at both ends. These are designated as line segment end point 1 and line segment end point 2.
Each horizon coordinate is as follows.
The equator coordinates of line end point 1 are (AZM1, ALT1)
The equator coordinate of line segment end point 2 is (AZM2, ALT2).
This value is stored in the line segment data memory.

When the program starts, data is first read from the line segment data memory. Subsequently, the coordinates of the line segment end point 1 and the line segment end point 2 are converted by the coordinate conversion means to obtain screen coordinates (CX1, CY1)-(CX2, CY2). After that, if a line connecting (CX1, CY1) and (CX2, CY2) is drawn on the projector screen, a line connecting the horizontal coordinate (AZM1, ALT1) and the horizontal coordinate (AZM2, ALT2) will be displayed on the dome screen. Will be drawn.
FIG. 13 shows how line segments are correctly projected by executing the above program.
FIG. 13A illustrates the data of the line segments (line segment end point 1 and line segment end point 2) stored in the line segment data memory in an easy-to-understand manner. Such an image is actually prepared. Do not mean. FIG. 13B shows a state in which the coordinates of the line segment end point 1 and the coordinates of the line segment end point 2 are converted into coordinates on the projection screen by coordinate conversion and drawn on the projection screen. FIG. 13C is a perspective view of the projection screen projected by the projector. It can be seen that the line segments are correctly projected along the horizontal coordinate scale on the dome.

  By applying line segment drawing in this way, polygons such as triangles and quadrilaterals, and even complex figures can be drawn. Also, the coordinates of the feature points that make up the figure can be defined not only by horizon coordinates, but also by equator coordinates and zodiacal coordinates, which can be converted to horizon coordinates by coordinate transformation. If the coordinates of the star defined by the zodiac coordinates are used as feature points, it is possible to draw a point connecting the star and the star and draw a constellation line to show the constellation in an easy-to-understand manner.

Next, instead of using the parameter calculation apparatus shown in FIGS. 7 and 8 as means for correcting image distortion, an example using an interpolation method will be described.
Using a stellar projector as shown in FIG. 3, the video camera is set so that the center of the screen has a certain level of horizon altitude and azimuth. Then, using the system of FIG. 7 or FIG. 8, coordinates (X, Y) on the computer screen are acquired by matching the position of the cursor. In addition, a device capable of performing calculation by the interpolation method is connected instead of the parameter calculation device 40 connected to the storage device 39 (62). The acquired data includes the horizontal coordinate (azimuth, altitude) of the video camera screen center at that time and the coordinates (X, Y) of the cursor that is projected in accordance with the video camera screen center. The data is stored in the storage device 39 (62) as horizon coordinate-screen coordinate correspondence data.

If this operation is repeated by changing the azimuth and altitude of the center of the video camera in steps of a fixed angle (for example, by 10 degrees), the horizon coordinate-screen coordinate correspondence data can be acquired in a collective form. Of these, the screen coordinates are collectively displayed on the computer screen as shown in FIG. 16 (horizontal coordinates (azimuth angle, altitude) are shown together to aid understanding). Further, FIG. 17 shows that these points are connected by a straight line.
Here, for example, when you want to project some image on the dome at a position with an azimuth angle of 10 degrees and an altitude of 10 degrees, from the horizon coordinate-screen coordinate correspondence data acquired here, the azimuth is 10 degrees and the altitude is 10 degrees. It is only necessary to select screen coordinates corresponding to the data and display the screen coordinates. However, in this case, it is not possible to set the altitude and azimuth of the image to be displayed in this case only with a jump value of 10 degrees. However, as can be easily guessed by looking at FIGS. 16 and 17, even if this value is in the middle, it is easy to interpolate from neighboring values, and the azimuth and altitude to be displayed are halfway values. Even if it exists, the screen coordinate corresponding to this can be calculated | required by interpolation calculation.

An error always occurs in the interpolation calculation. However, if the interpolation algorithm is a curve rather than a straight line, for example, a quadratic or cubic equation, or the interval between the obtained horizontal coordinate-screen coordinate correspondence data is made finer, the accuracy is sufficient. Can be raised.
Here, an embodiment in which an image having a certain area is displayed using this interpolation method will be described. When the angle, position, rotation angle, etc. for displaying the original image to be displayed are determined, the horizon coordinates corresponding to each pixel of this image can be obtained. The horizontal coordinates are obtained for each pixel, the coordinates on the screen are obtained from the horizontal coordinates by the above method, and the pixels are drawn there. If this is repeated, the image is displayed at the correct position on the dome screen.

Next, the complement method will be described.
By the above method, the horizon coordinate-screen coordinate correspondence data is acquired and stored in the storage device 39 (62) while changing the azimuth and altitude in constant increments (azimuth increment value is dazm and angle increment value is dalt). It is assumed that the position (coordinates) on which the point of the horizontal coordinates (azmP, altP) should be displayed on the screen is obtained.
In the set of horizon coordinate-screen coordinate correspondence data acquired previously, four values (reference points) in the horizon coordinate that surround the value to be displayed in a rectangle are selected. This is as follows.
Point 00: (azm0, alt0) (x00, y00)
Point 01: (azm1, alt0) (x01, y01)
Point 10: (azm0, alt1) (x10, y10)
Point 11: (azm1, alt1) (x11, y11)
Here, the altitudes (= alt0) of the points 00 and 01 are equal. Similarly, the azimuth angle (= azm1) of point 01 and point 11 is also equal.

It is assumed that the following relationship holds with the horizontal coordinate of the point (point P) to be displayed.
azm0 ≤ azmP ≤ azm1
alt0 ≤ altP ≤ alt1
By the way
azm1−azm0 = dazm
alt1−alt0 = dalt
It is.
FIG. 18 is a plot of these four reference points and point P in horizon coordinates.
Here, with the point 00 as a reference, the azimuth angle of the point P with respect to the azimuth increment value is taken as the azimuth relative value of the point P.
Azimuth relative value of point Pazmr = (azmP-azm0) / dazm
Similarly, for altitude, altitude relative value altr = (altP-alt0) / dalt
Is required.

Here, FIG. 19 is a plot of the four reference points and the point P in screen coordinates.
The screen coordinates of the point P are unknown, but interpolation is performed using the intermediate point here.
The interpolation point (xt0, yt0) between points 00 and 10 is
xt0 = (x10−x00) * altr
yt0 = (y10−y00) * altr
As required.
Similarly, the interpolation point (xt1, yt1) between points 10 and 11 is
xt1 = (x11−x01) * altr
yt1 = (y11−y01) * altr
It becomes.

Next, the on-screen coordinates (xP, yP) of the point P can be obtained by interpolating the interpolation points.
xP = (xt− xt0) * azmr
yP = (yt1 − yt0) * azmr
This embodiment is the most primitive example in which the interpolation calculation is performed by a linear expression. If the acquisition interval of the horizon coordinate-screen coordinate correspondence data is not sufficiently small, the accuracy of the interpolation is lowered. It can be calculated by interpolating with higher accuracy by interpolating with a high-order expression such as quadratic or cubic.
In this way, if there is a set of horizon coordinate-screen coordinate correspondence data obtained over a sufficiently wide range, screen coordinates corresponding to an arbitrary azimuth and altitude can be acquired.

Here, the means for correcting the distortion of the image (the amount of deviation of the image from the position that should be projected by the video projector with respect to an image point such as a star by the stellar projector) is summarized as follows.
(1) Coordinate conversion is performed by interpolation calculation based on sampled screen-horizontal coordinate correspondence data (data stored in the storage means having the configuration of FIG. 7 or FIG. 8).
(2) Based on the sampled screen-horizontal coordinate correspondence data, the position, attitude angle, and other information (optical characteristics, focal length, etc.) that are parameters of the projector are calculated. Perform coordinate transformation of coordinates.
(3) Correction is performed by a method using both of the above two methods (coordinate conversion is performed by the method (2) and the remaining error is further corrected by the method (1)).
In these embodiments, the center of the screen is the position where the cursor is positioned within the screen of the video camera, but it may not be the center of the screen in practice. When the video camera is mounted on a stellar projector and the center of the stellar projector is installed at the center of the dome screen, the optical axis of the video camera does not necessarily intersect the center of the stellar projector, and the latitude axis Even if the diurnal axis and the optical axis of the video camera are not necessarily orthogonal to each other, the predetermined screen coordinates on the video camera correspond to the altitude azimuth point of the stellar projector. Of course, it is included in the scope of the present invention if it is handled in the same way as the screen center coordinates of the video camera.

  A device that calculates the position and orientation of the true video projector by interpolating the distortion of the image projected by the video projector (deviation from the position to be projected on the projector screen) when installing a star projector and a video projector in a planetarium facility It is a system which corrects by

It is the schematic which shows the horizontal coordinate on a dome screen. It is the figure which drew the coordinate line of the horizon coordinate by the orthogonal coordinate, and the figure which projected the coordinate line of the horizon coordinate on the screen. It is a perspective view which shows the example of an image | video projected on the screen of a projector. It is a figure which shows the example of an image projected with the correct setting of the screen of a projector. It is a figure which shows the example of an image projected when the direction of a projector has shifted | deviated 2 degree | times upwards. It is a figure which shows the example of an image | video projected when the focal distance of a lens is short. It is a side view of the dome theater which shows an example of the image projection system by this invention. It is a figure for demonstrating embodiment of the stellar projector used for the image | video projection system by this invention. It is a perspective view for demonstrating the detail of the camera unit which provided the video camera independently of the stellar projector. It is a figure for demonstrating an example of the correction | amendment control method in the case of installing a camera unit in the position shifted | deviated from the dome center. It is a figure for demonstrating the attitude | position angle of a projector. It is a figure for demonstrating the azimuth and altitude with respect to the position of the point image on a dome screen. It is a figure for demonstrating the position of a video projector. It is a block diagram which shows embodiment of the aligning apparatus of the cursor of a video projection system by this invention, and a video camera screen center. It is a block diagram which shows other embodiment of the alignment apparatus of the cursor of a video projection system by this invention, and a video camera screen center. It is a block diagram which shows embodiment of a parameter calculation apparatus. It is a figure which shows the master image drawn with the horizon image used when converting an image into a projection screen by carrying out coordinate conversion. It is a flowchart for demonstrating the operation | movement which carries out coordinate conversion of an image, converts into a projection screen, and draws. It is the figure which showed the procedure in which a master image is coordinate-transformed and correctly projected on a dome screen. It is the figure which showed the procedure in which figure data was coordinate-transformed and correctly projected on a dome screen. It is the schematic which shows embodiment of the image | video projection system which installed the camera. It is a figure which shows the installation structure of a video projector. It is a figure for demonstrating interpolation calculation, and is the figure which displayed the screen coordinate collectively on the computer screen. It is the figure which connected and showed each point of FIG. 16 with the straight line. It is the figure which showed the four reference points of the neighborhood, and the point P enclosed by this by the horizon coordinate. It is the figure which showed the neighboring four reference points and the point P enclosed by this with screen coordinates.

Explanation of symbols

1,42,63 Dome screen 2,17,37 Stellar projector
3,33 Video projector 4 Cursor 5 Point image 6 Video projector image a
7 Computer (control device)
10, 15, 16, 41 Laser pointer (reference marker projector)
11 Support frame 12 Pedestal 18, 57 Camera 30 Cursor position operation device (mouse)
Reference Signs List 31 Cursor coordinate setting device 32 Cursor display device 34, 56 Cursor image 35 Horizon coordinate setting device 36 Servo control device 38, 61 Video camera screen center 39, 62 Horizon coordinate-screen coordinate correspondence data storage device 50 Video capture unit 51 Image processing device 52 Differential Operation Unit 53 Cursor Coordinate Setting Device 65a to 65n Coordinate Conversion Device 1 to n
66a to 66n Screen coordinate error calculation devices 1 to n
67 Accumulator 71 Camera Optical Axis 72 Azimuth Axis 73 Azimuth Axis Motor 74 Altitude Axis Motor 75 Azimuth Turntable 76 Base 77 Prop 78 Rotator 80 Camera Screen Center Point 81 Camera Unit 82 Video Screen Display Monitor

Claims (11)

A projector capable of projecting an image output from image generation means such as a computer or a video apparatus onto a dome-shaped screen having a curved surface, and capable of projecting an image as a mark that can be arbitrarily moved on the screen;
A camera having direction control means on the dome- shaped screen, capable of controlling the direction toward coordinates on a predetermined screen;
And Align means Align the position of the camera screen of the mark on a given coordinate,
Storage means for storing the coordinates on the projection screen of the image that is the landmark matched by the positioning means and the coordinates on the screen facing the camera;
Coordinate conversion parameter calculation means for obtaining a coordinate conversion parameter between the coordinates on the screen and the coordinates on the projection screen using the coordinates on the projection screen of the plurality of coordinates on the screen facing the camera stored in the storage means and the mark as a mark When,
Coordinate conversion means for performing coordinate conversion from coordinates on the screen to coordinates on the projection screen or from coordinates on the projection screen to coordinates on the screen using the coordinate conversion parameters;
Equipped with a,
The alignment means includes
Control means for extracting a position of an image serving as a mark from a photographed image of the camera and controlling an image position serving as a mark output from the projector so that the image position serving as the mark matches a predetermined position on the camera screen When,
Video projection system, comprising a. A projector capable of projecting an image output from image generation means such as a computer or a video apparatus onto a dome-shaped screen having a curved surface, and capable of projecting an image as a mark that can be arbitrarily moved on the screen;
A camera having direction control means on the dome-shaped screen, capable of controlling the direction toward coordinates on a predetermined screen;
Alignment means for aligning the position of the mark in the camera screen with predetermined coordinates;
Storage means for storing the coordinates on the projection screen of the image that is the landmark matched by the positioning means and the coordinates on the screen facing the camera;
Coordinate conversion parameter calculation means for obtaining a coordinate conversion parameter between the coordinates on the screen and the coordinates on the projection screen using the coordinates on the projection screen of the plurality of coordinates on the screen facing the camera stored in the storage means and the mark as a mark When,
Coordinate conversion means for performing coordinate conversion from coordinates on the screen to coordinates on the projection screen or from coordinates on the projection screen to coordinates on the screen using the coordinate conversion parameters;
With
The alignment means includes
An operating device capable of manually moving the image serving as the mark in the projection screen;
An image projection system, wherein an image serving as a mark is aligned with a predetermined position on a camera screen by the operation device. A projector capable of projecting an image output from image generation means such as a computer or a video apparatus onto a dome-shaped screen having a curved surface, and capable of projecting an image as a mark that can be arbitrarily moved on the screen;
A camera having direction control means on the dome-shaped screen, capable of controlling the direction toward coordinates on a predetermined screen;
Alignment means for aligning the position of the mark in the camera screen with predetermined coordinates;
Storage means for storing the coordinates on the projection screen of the image that is the landmark matched by the positioning means and the coordinates on the screen facing the camera;
Coordinate conversion parameter calculation means for obtaining a coordinate conversion parameter between the coordinates on the screen and the coordinates on the projection screen using the coordinates on the projection screen of the plurality of coordinates on the screen facing the camera stored in the storage means and the mark as a mark When,
Coordinate conversion means for performing coordinate conversion from coordinates on the screen to coordinates on the projection screen or from coordinates on the projection screen to coordinates on the screen using the coordinate conversion parameters;
With
The alignment means includes
A control means for extracting a position of an image serving as a mark from a photographed image of the camera, and controlling a direction in which the camera is directed so as to match a predetermined position on the camera screen with the image position serving as the mark;
Have
The camera is mounted on a stellar projector,
An image projection system characterized in that the means for changing the direction of the camera uses angular position control means of the rotation axis of the stellar projector. A projector capable of projecting an image output from image generation means such as a computer or a video apparatus onto a dome-shaped screen having a curved surface, and capable of projecting an image as a mark that can be arbitrarily moved on the screen;
A camera having direction control means on the dome-shaped screen, capable of controlling the direction toward coordinates on a predetermined screen;
Alignment means for aligning the position of the mark in the camera screen with predetermined coordinates;
Storage means for storing the coordinates on the projection screen of the image that is the landmark matched by the positioning means and the coordinates on the screen facing the camera;
Coordinate conversion parameter calculation means for obtaining a coordinate conversion parameter between the coordinates on the screen and the coordinates on the projection screen using the coordinates on the projection screen of the plurality of coordinates on the screen facing the camera stored in the storage means and the mark as a mark When,
Coordinate conversion means for performing coordinate conversion from coordinates on the screen to coordinates on the projection screen or from coordinates on the projection screen to coordinates on the screen using the coordinate conversion parameters;
With
The alignment means includes
Has an operating device that can manually move the direction of the camera,
A predetermined position on the camera screen is aligned with the image serving as a mark by the operation device,
The camera is mounted on a stellar projector,
An image projection system characterized in that the means for changing the direction of the camera uses angular position control means of the rotation axis of the stellar projector. 5. The video projection system according to claim 1 , wherein the coordinate conversion parameter is a position where a projector is installed, a posture angle, a focal length of a projection lens, or any combination thereof. A projector capable of projecting an image output from image generation means such as a computer or a video apparatus onto a dome-shaped screen having a curved surface, and capable of projecting an image as a mark that can be arbitrarily moved on the screen;
A camera on the dome- shaped screen that can be turned to a predetermined coordinate on the screen;
And Align means Align the position of the mark on a given coordinate in the screen of the camera,
Storage means for storing the coordinates on the projection screen of the image that is the landmark matched by the positioning means and the coordinates on the dome screen facing the camera;
Interpolation that performs coordinate conversion between the on-screen coordinates of the arbitrary position on the screen and the projected screen coordinates using the plurality of on-screen coordinates facing the camera and the coordinates on the projected screen stored in the storage means. Computing means;
Equipped with a,
The alignment means includes
Control means for extracting a position of an image serving as a mark from a photographed image of the camera and controlling an image position serving as a mark output from the projector so that the image position serving as the mark matches a predetermined position on the camera screen When,
Video projection system, comprising a. A projector capable of projecting an image output from image generation means such as a computer or a video apparatus onto a dome-shaped screen having a curved surface, and capable of projecting an image as a mark that can be arbitrarily moved on the screen;
A camera on the dome-shaped screen that can be turned to a predetermined coordinate on the screen;
Alignment means for aligning the position of the mark in the camera screen with predetermined coordinates;
Storage means for storing the coordinates on the projection screen of the image that is the landmark matched by the positioning means and the coordinates on the dome screen facing the camera;
Interpolation that performs coordinate conversion between the on-screen coordinates of the arbitrary position on the screen and the projected screen coordinates using the plurality of on-screen coordinates facing the camera and the coordinates on the projected screen stored in the storage means. Computing means;
With
The alignment means includes
An operating device capable of manually moving the image serving as the mark in the projection screen;
An image projection system, wherein an image serving as a mark is aligned with a predetermined position on a camera screen by the operation device. A projector capable of projecting an image output from image generation means such as a computer or a video apparatus onto a dome-shaped screen having a curved surface, and capable of projecting an image as a mark that can be arbitrarily moved on the screen;
A camera on the dome-shaped screen that can be turned to a predetermined coordinate on the screen;
Alignment means for aligning the position of the mark in the camera screen with predetermined coordinates;
Storage means for storing the coordinates on the projection screen of the image that is the landmark matched by the positioning means and the coordinates on the dome screen facing the camera;
Interpolation that performs coordinate conversion between the on-screen coordinates of the arbitrary position on the screen and the projected screen coordinates using the plurality of on-screen coordinates facing the camera and the coordinates on the projected screen stored in the storage means. Computing means;
With
The alignment means includes
A control means for extracting a position of an image serving as a mark from a photographed image of the camera, and controlling a direction in which the camera is directed so as to match a predetermined position on the camera screen with the image position serving as the mark;
Have
The camera is mounted on a stellar projector,
An image projection system characterized in that the means for changing the direction of the camera uses angular position control means of the rotation axis of the stellar projector. A projector capable of projecting an image output from image generation means such as a computer or a video apparatus onto a dome-shaped screen having a curved surface, and capable of projecting an image as a mark that can be arbitrarily moved on the screen;
A camera on the dome-shaped screen that can be turned to a predetermined coordinate on the screen;
Alignment means for aligning the position of the mark in the camera screen with predetermined coordinates;
Storage means for storing the coordinates on the projection screen of the image that is the landmark matched by the positioning means and the coordinates on the dome screen facing the camera;
Interpolation that performs coordinate conversion between the on-screen coordinates of the arbitrary position on the screen and the projected screen coordinates using the plurality of on-screen coordinates facing the camera and the coordinates on the projected screen stored in the storage means. Computing means;
With
The alignment means includes
Has an operating device that can manually move the direction of the camera,
A predetermined position on the camera screen is aligned with the image serving as a mark by the operation device,
The camera is mounted on a stellar projector,
An image projection system characterized in that the means for changing the direction of the camera uses angular position control means of the rotation axis of the stellar projector. The camera is mounted on a stellar projector,
8. The image projection system according to claim 1 , wherein the means for changing the direction of the camera uses angular position control means of a rotation axis of the stellar projector. Dome screen on coordinates the camera oriented claim 6, 7, 8, 9 or 10, wherein it is a horizontal coordinate represented by altitude and azimuth Video projection system.

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