JPS593685B2 - photographic image scanning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides the ability to generate epipolar lines from a single photographic image.
The present invention relates to a scanning device of the type that generates image data along lar 1ines and stores the image data for subsequent data processing and ground preparation.

The technology for creating maps from aerial photographs has advanced rapidly over the past 20 years.

The technique has evolved from manual measurements and calculations and is now capable of aligning conjugate image points, calculating parallax data, and plotting various types of maps from a pair of solid or stereoscopic images. A fully automated system is obtained.

The map consists of a relatively simple orthogonal map that transforms the image details of a photograph from the original projection to an orthogonal projection with image correction and geometric deviation correction. There is a complex contour map that shows the

In early photogrammetric semi-automatic plotting machines, conjugate image points on two stereoscopic or stereophotographs were superimposed by the operator by visual observation.

In this specification, a conjugate image point is defined as the same image point on two different entity images.

An electrical signal representing the displacement required to superimpose the conjugate image points on the two solid images is now used along with other electrical signals to create the desired map.

Electronic correlation methods were then developed to detect conjugate image points from electro-optically derived signals generated by scanning two solid images.

A representative electronic correlation method is described in ζ U.S. Patent No. 3,548,210.
It is disclosed in the specification of No.

This correlation can be performed with analog techniques or also with digital methods.

With the advent of this correlation method, manual operator intervention was no longer required, resulting in a system that made the stereogrammer almost completely automatic.

Further improvements were made to the automatic entity diagrammer, which was published in U.S. Patent No. 3.
The Evipolar ray principle disclosed in No. 726,591 was developed.

This Ebipolar i-line method significantly increases the ability to reliably scan conjugate image areas, reduces the complexity of the scan pattern, and significantly simplifies the structure of the scanning and correlation equipment used. It was done.

This prior art is uniquely suited to photogrammetric mapping or cartography machines in which data from two solid images are generated simultaneously and the correlation of the data to determine the conjugate image portion is performed on a real-time basis. This is what is being done.

Although such automated stereogrammers have very favorable performance, the requirement for real-time operation makes the mechanical system very complex and expensive.

In many practical cartographic tasks, such as the creation of orthographic maps, sacrifices can be made in the number of conjugate points processed for real-time operation for the purpose of simplicity and cost savings. It is.

It is therefore an object of the present invention to provide a relatively simple single-photo Epipolar scanning device for generating image data along an Epipolar line by scanning only one photo image at a time. .

A single-photo Epipolar scanning device according to the present invention includes a base, a micro-densitometer firmly attached to the base for detecting image details or details within a predetermined area of the photograph, and a micro-densitometer mounted firmly on the base for detecting image details or details within a predetermined area of the photograph. a mechanical stage for translating a photographic image relative to the microdensitometer; a control device for operating the mechanical stage to translate the photographic image relative to the microdensitometer along an Epolar line; and a storage device for storing the image data.

The micro-densitometer can also scan one or more Ebipolar lines during each mechanical translation, and parallel to each Ebipolar line to remove Y-axis parallax a posteriori during data processing. Data can also be generated along adjacent lines.

The proposal according to the invention is feasible.

This is because the Ebipolar scanning method allows reliable position detection of the conjugate Ebipolar line of an image in a stereophotograph pair.

Therefore, the configuration of such an Ebipolar line on the image can be easily determined, and the image scanning movement can be controlled based on this, thereby eliminating the need to simultaneously scan two images on a real-time basis. Gender is dissolved.

Each photographic image of the stereophotograph pair can be scanned one at a time and the data generated can be stored for subsequent processing and mapping operations.

Scanning each image separately and storing the image data obtained therefrom, reliable reconstruction of the conjugate image portion is possible according to the invention, so that the need to scan two stereophotographic images simultaneously; The need for on-line processing of generated image data and the associated complex and expensive equipment has been eliminated.

Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a preferred embodiment of a single-picture epipolar scanning device according to the present invention.

The scanning device 10 is mounted on a sturdy base 14 and has f,
- It has a Y measurement stage 12.

This X-Y measurement stage 12 has a top surface 1 of a base 14.
an X-axis gear ridge 16 attached to 8 and adapted to move parallel to the surface;
The base 140 has an X-axis gear ridge 20 mounted thereon and moved parallel to the top surface 18.

The X and Y coordinates of the device are indicated by coordinate arrows 22 in the left part of the diagram.
It is shown in

The X-axis gear ridge 16 is supported along one edge by a rod 24 slidably inserted into a passage 26 formed along one edge thereof.

The rod 24 is also supported at both ends by upright brackets 28 and 30 secured to the base 14.

The other line of the X-axis gear ridge 16 is supported by a threaded shaft 32 passing through a threaded passageway 34 formed therealong.

The ends of the screw shaft 32 are supported by upright brackets 36 and 38 secured to the base 14.

Rod 24 and threaded shaft 32 are arranged parallel to surface 18 of base 14 to force movement of the X-axis gear ridge in the Y-axis direction parallel to the base.

The ends of threaded shaft 32 project beyond brackets 36 and 38 and are adapted to receive a Y-axis manual wheel 40 at one end and an X-axis servo drive 42 at the other end.

The X-axis gear ridge 20 has a passage 46 formed on one edge thereof.
It is supported along one edge by a rod 44 which is slidably inserted through the .

The rod 44 is also supported at its ends by upright brackets 48 and 50 that are secured to the X-axis gear ridge 16.

The threaded shaft 52 is inserted into a threaded passage 54 formed along the other line of the X-axis gear ridge 20, and the threaded shaft 52 is inserted into the threaded passage 54 formed along the other line of the
I support the other line.

The ends of threaded shaft 52 are supported by upright brackets 56 and 58 secured to X-axis gear ridge 16.

Rod 44 and threaded shaft 58 are arranged parallel to surface 18 of base 14 to force movement of the X-axis gear ridge in the X-axis direction parallel to the base.

The ends of threaded shaft 52 project beyond brackets 56 and 58 and are adapted to receive an X-axis manual wheel 60 at one end and an X-axis servo drive 62 at the other end.

The X-axis gear ridge 16 can be moved in either direction along the Y-axis by manually rotating the wheel 40 or alternatively by electrically actuating the X-axis servo drive 42.

As mentioned above, since the X-axis gear ridge 20 is attached to the X-axis gear ridge 16, the X-axis gear ridge 16
Mechanical movement in the axial direction will also cause the X-axis gear ridge 20 to be moved by the same amount in the Y-axis direction.

The X-axis gear ridge 20 can be moved in any direction along the Y-axis by manually rotating the wheel 60 or alternatively by electrically actuating the X-axis servo drive 62.

The movement of the X-axis gear ridge 20 in the X-axis direction can be performed independently of the movement of the X-axis gear ridge 16.

The photographic image 64 to be scanned is fixedly attached to the X-axis gear ridge 20 by suitable mounting means and moved therewith.

The coordinated movement of the X-axis gear ridge 20 and the X-axis gear ridge 16 along the Y-axis and the independent movement of the It is possible to scan in coordinate or coordinate motion.

In the preferred embodiment shown, the X-Y stage or
Although the Y stage 12 has been described as using guide rods and threaded shafts to forcefully drive the individual carriages along the It goes without saying that other types of X-Y carriages, such as a V-groove type carriage (carriage), can be used as well.

The manner in which the carriage is forced and driven is not critical to the invention.

The image details on the photographic image 64 are input to the input unit 202.
and is converted into an electrical signal by a microdensitometer having a detector 204.

Details of the input and detector are shown in FIGS. 4, 5 and 6.

It should be noted that FIGS. 4, 5, and 6 illustrate various embodiments of densitometers capable of generating data along multiple lines during each X-axis scan.

The input unit 202 is fixed to the base 14 and irradiates a predetermined area of the photographic image 64 from below.

Detector 204 is fixedly disposed above photographic image 64 and receives light from an input section modulated by the photographic image.

It then generates electrical signals representing the details of the image being illuminated.

The detector 204 is rigidly supported above the photographic image 64 in optical alignment with the input optical system by a corner bracket support member 66 affixed to the base 14 .

The illuminated area can be a single point, a series of points, or a line image of a predetermined length, as described below with reference to FIGS. 4, 5, and 6.

To conveniently align the densitometer with a selected point on the photographic image 64, the scanning device 10 further includes a low magnification microscope 300 in combination with the input 202 and the detector 204.
is provided.

Details of this low magnification microscope 300 are shown in FIG. 4, and will be described in detail later with reference to the same figure.

The single-photo Ebi-polar scanning device further includes an X-axis servo drive to translate the photographic image 64 relative to the micro-densitometer so that the area illuminated by the micro-densitometer scans along the Ebi-polar line on the photographic image. 42 and an X-axis servo drive 62 for generating an epipolar scan signal.

The scan controller 68 generates control signals based on external information provided in a suitable form.

This external signal can be obtained from a pre-prepared program carrier, such as a perforated tape, a perforated card or a magnetic tape, as in the case of well-known numerical controls designed to drive machine tools etc. can.

In a more complex or sophisticated embodiment, the scanning controller 68 may include a special purpose logic device, such as a mini-computer, also commonly used in numerically controlled machines, to provide microdensitometer and evipolar control. The movement of photographic image 64 required to scan along the line can also be calculated.

In this case, controller 68 can perform more complex tasks.

For example, when external information is relatively incomplete, a minicomputer can perform interpolation and geometric calculations similar to those performed by existing entity mapping machines to drive the X-Y stage. We will be able to obtain the final data for

Furthermore, the minicomputer stores, i.e., the memory device 7.
It would also be possible to perform zero control or drive.

Those skilled in the art will be familiar with the electrical logic circuitry that generates the signals for the X- and Y-axis drives and the drive signals for the storage device or memory 10 for scanning along the Epolar line when the pattern is known. As I know,
There seems no need to discuss it in detail.

The electrical signals representing the images on the photographic image 64 scanned along the individual epipolar lines are stored in the storage device γ0 for later data processing.

The electrical signals may be stored in analog storage, or alternatively, the electrical signals may be converted to digital data and stored in digital memory.

As is obvious to those skilled in the art, there are several storage methods for the latter.
bring benefits.

Although any digital storage device may be used, magnetic tape or magnetic tape is believed to be particularly suitable.

Such storage devices can be used in conjunction with commercially available general purpose computers to perform efficient off-line correlation and other processing.

Also, special purpose computers and auxiliary processors could be used if considered advantageous.

The operation of the single photo Epipolar scanning device is as follows.

A photographic image with known parameters of an Epolar scanning pattern is input to the input section 202 of the microdensitometer as shown in FIG.
and the detector 204 on the X-axis gear ridge.

Using low magnification microscope 300, the area illuminated by the densitometer is aligned with a predetermined image point on photographic image 64 while manually rotating X-axis wheel 60 and Y-axis wheel 40.

The scan controller 68 is then activated to generate overscan control signals based on the parameters of the Epolar scan pattern inserted into the device 68.

This scan control signal operates the X-axis servo drive unit 62 and the
Move 4.

The electrical signals generated by the microdensitometer are stored in a storage device 70 in analog or digital form.

After scanning the first photographic image and storing the data in the storage device 10, the first photographic image is removed and the second photographic image 64', which is the other photographic image of the stereophotograph pair, is placed on the X-axis gear ridge. Install.

The same process is performed for the second photographic image 64' and the resulting image data is also stored in the storage device 70.

As will be clear to those skilled in the art, in many practical mapping applications, where the necessary subsequent data processing can be performed on a real-time basis with data generation from a second photographic image,
It is not necessary to store data from the second photographic image.

In such a case, the data from the second image could be input directly to the processor, with the conjugate data of the first image being retrieved from storage 70 as needed.

FIG. 2 is an explanatory diagram to provide a clearer understanding of the principle of the Ebipolar line disclosed in U.S. Pat. No. 3,726,591 and employed in a single photo Ebipolar scanning device.

Two stereographic images 102 and 104 of a scene or surface 106 are shown taken from two different shooting points 108 and 110 at different altitudes.

Corresponding Ebipora on entity images 102 and 104 → 112
and 114 are defined by one plane 116 of the evipora intersecting the two photographic images.

A plane 116 of Ebipora is defined by the shooting points 108 and 110 and a point 118 on the ground surface 106 .

Photographic images 102 and 10 such as lines 120 and 122
4, the different Ebipolar planes 116 on IJ are 1
This can occur by rotating to the position shown at 24.

Echhorrer lines on the solid image 102 are straight lines that define a fan-shaped pattern that radiates from a point 126 in the plane of the image 102.

Point 126 is the intersection of the line connecting shooting points 108 and 110 and the plane of image 102.

Similarly, other epipolar lines on the real image 104 consist of straight lines radiating from the point 128.

Point 128 is the point on the plane of the real image 104 where the projection of the line connecting the shooting points 108 and 110 intersects the plane of the real image 104 .

This Ebipolar method has the advantage that the conjugate image portion on the two photographic images is located along the conjugate line, thereby allowing reliable positioning of the conjugate image portion in the stereophotographic pair of images. .

Referring to FIG. 3, another embodiment of a single photo epipolar scanning device 10 is shown.

This embodiment includes a rotatable stage to facilitate scanning of the sector pattern formed by the Ebipolar i-rays.

Elements shown in Figure 3 that correspond to those in Figure 1 have been given the same reference numerals to avoid confusion.

In addition to the base 14 and the X-Y stage 12, this embodiment has a rotatable carriage γ2.

This rotatable carriage T2 has an X-axis gear ridge 20
It has a base 74 with a circular opening adapted to rotatably receive a rotating member 18 attached thereto.

An annular bearing (not shown) or other bearing member may be interposed between the base 74 and the rotating member 18 to allow the opening arrow to move without appreciable lateral or horizontal movement of the rotating member T8. Allow it to rotate freely inside.

A plurality of teeth 80 are formed around the periphery of rotating member γ8 to engage a worm gear 82 that is mounted concentrically on shaft 84 and adapted to rotate therewith.

The shaft 84 is rotatably supported at its ends by upright brackets 86 and 88 which are secured to the base 74.

The ends of shaft 840 project from brackets 86 and 88 and are adapted to receive manual wheel 90 at one end and servo drive 92 at the other end.

Rotation of the shaft 840 by rotating the hand wheel 90 or electrically actuating the servo drive 92 will rotate the worm gear 83 in engagement with the teeth 80 and cause the rotating member 18 to rotate. .

Photographic image 64 is mounted on rotating member 78 and rotates therewith.

In the specific example of FIG. 3 as well, a scan controller 68 generates a control signal to control the rotation of the rotatable stage 120.

The operation of the embodiment of FIG. 3 is also similar to that of the embodiment of FIG.

However, due to the addition of the rotation stage, the scanning signals generated by the scanning controller are simplified.

Photographic image 64 is mounted on rotation stage 18 and oriented while viewed through microscope 300 by rotating manual wheels 40, 60 and 90 as before.

Instead of a scan controller generating a configuration control signal for the X-Y stage which produces a combined motion of both stages to follow the Epolar line, the image is rotated by an appropriate signal to the rotary stage. Ebipolar being scanned
The lines can be along the X-axis, and the scanning of each epipolar line can be a simple X-axis translation.

Each time the photograph is moved in the Y direction to the next epipolar line, the rotary stage is indexed so that the next line is also along the X axis.

Details of the densitometer 200 are shown in FIG.

Input optics 202 includes a light source consisting of a lamp 206 that illuminates a bin hole aperture 208 formed in an opaque aperture plate 210 by a condenser or condenser lens 212, as shown.

The light from lamp 206 that passes through the bin hole opening is
It is focused by a focusing lens 216 to a point 214 on the photographic image 64.

The detector 204 collects the light modulated by the image detail onto the photographic image 64 and is incident on a point 214, and sends it to a detection element 220.
It has a condenser lens 218 that focuses upward.

Detection element 220 generates an electrical signal representing the intensity of the received light.

As shown, a low magnification microscope 300 is provided in combination with the densitometer optical system.

The microscope is equipped with a light source in the form of a lamp 302 which illuminates the area around point 214 via a beam splitter 304 and a condenser lens 218.

Lamp 302 is spaced from the condenser lens at a spacing approximately equal to the focal length of condenser lens 218 such that photographic image 64 is illuminated by approximately parallel light.

The collimated beam passes through the photographic image 64 and is partially reflected by the beam splitter 306 to the microscope objective 308.

The objective lens forms an aerial image portion 310 of the illuminated portion of the photographic image, and this image is transmitted to the intermediate lens 314.
is projected onto the eyepiece lens 312 of the microscope.

The microscope can be provided with polarizing optics, such as mirrors or prisms, to position the eyepiece 312 at a convenient location for the operator 318.

It will be appreciated that suitable housings and optical shields (not shown) may be provided as is customary in optical equipment design.

Another embodiment of a MicroKey densitometer capable of scanning multiple lines during each X-axis Epolar scan is shown in FIG.

In the specific example of FIG. 5, the light source 206 is
A narrow slit opening 222 formed in an opaque diaphragm plate 224 is irradiated through the diaphragm 26 .

The slit opening 222 is positioned approximately perpendicular to the X-axis of the device.

In the illustrated embodiment, the X-axis extends perpendicular to the plane of the drawing and passes through the centerline 228 of the illustrated optical system.

The light passing through the slit opening 222 is focused onto the photographic image 64 by the lens 230.

The length of the slit image on the photographic image 64 is the point 232, 234
and 236, each of which is long enough to cover the image points indicated by .

The light forming the slit image passes through the photographic image 64 and is modulated by the image details on the photographic image.

The modulated slit light image of the photographic image 64 is located at the point 232°2
The modulated light emanating from each of 34 and 236 is focused onto three detection elements 238, 240 and 242 arranged parallel to the slit aperture for detection.

Points 232, 234 and 236 may be formed by the inherent aperture of the sensing element, or alternatively by a → bin hole (not shown) placed in front of the sensing element.

Although three separate sensing elements are shown in the illustrated embodiment, the individual sensing elements may be, for example, a linear array of charge-coupled devices, a packet, a linear array of brigade devices.

A linear array of photomultiplier tubes with individual outputs for each photomultiplier channel, or other linear arrays of photodetectors, can be integrated into a single integrated device.

Elements of the microscope 300 are shown in the fifth column for ease of illustration.
It is omitted in the figure.

During a single X-axis scan of the photographic image, image lines or details are detected by detector 240 along the desired epipolar line defined by point 234.

Detectors 238 and 242 detect image details on the photographic image along lines parallel to the desired epipolar line at short intervals on either side of the Y-axis.

Since these lines are close to each other, the effect of the sector pattern of the Epipolar lines is negligible.

Furthermore, during subsequent data processing, data of adjacent lines can be utilized to eliminate residual Y-direction parallax that may be caused by other external factors.

In addition, if desired, three or more detectors as shown in the figure may be used.
Of course, data can be generated along more than one parallel line.

The three detectors shown are merely an illustrative example of the principles of the invention and are not intended to limit the scope of the invention.

FIG. 6 shows yet another embodiment of a microdensitometer 200 capable of scanning a plurality of Epipolar lines during a single scan in the X-axis direction of a photographic image.

The input optical system 202 is the same as that described with reference to FIG.
Lens 23 that illuminates a line area on the photographic image 64 parallel to the axis
0.

The line area on the photographic image 64 has a sufficient length to include a plurality of Epipolar lines.

In the illustrated example, the three individual Epipolar 4 are at point 2
46.248 and 250.

Instead of the fixed focal length lens 2440 shown in FIG. A lens 252 is used.

This zoom lens has image points 246.248 and 25
0 onto individual detector elements of a linear array of photodetectors 256.

In this example as well, the detector can be constructed from a plurality of independent detector elements as shown in FIG. Integrated linear detector arrays such as charge coupled devices, packet brigade devices and other detectors may also be used.

In fact, it is sufficient that the detector array 256 has at least one independent detector element for each epipolar line being scanned.3 In practical applications, an integrated array 56, etc. A typical linear array can have over 1000 individual detector elements that are read out serially or sequentially.

However, this is not a serious problem.

This is because this serial succession can be accomplished in about 1 microsecond with existing equipment such as packet brigade devices.

A more serious problem is that the sensor or detector is an integrating device and requires a predetermined input (light intensity level x integration time) to achieve a satisfactory signal-to-noise ratio. That's the point.

Second, the motion of the X-axis gear ridge creates an undesirable smearing effect.

This is because the picture is being moved during the integration time.

This blurring can be controlled by gating the detector elements of the array, however, at the expense of integration time.

This problem could be overcome by replacing light source 260 with a high power gas discharge lamp that produces short duration, high energy flashes at a rate of 60 to 120 flashes per second.

These flashes or flashes are very brief and can therefore be considered to be a cessation of movement during that period;
Moreover, the energy of each pulsed light is high, which improves the S
The N ratio is obtained.

If such a configuration is used, the controller 68 must have additional circuitry that alternately generates a trigger signal for the discharge lamp and a readout signal for the integrated linear array.

The amount of concentration data from a linear array with a large number of detector elements is very large.

In fact, this amount of data is so large that digital storage can only be done on existing very expensive computers.

However, cost-effective compromises can easily be found.

Instead of storing all of the data generated by the detector elements, only the data from selected detectors representing the desired epipolar line is stored.

This selection control is provided by a control device 68 coupled to the scanner.
It could be realized by.

This selection method eliminates the need for expensive storage devices.

The operation of the specific example shown in FIG. 6 is as follows.

With the photographic image placed at one end of the X-axis scan field, the zoom lens is adjusted to focus the desired epipolar line onto the desired detector element of the detector array.

As the photographic image 64 is scanned along the Y-axis, the zoom lens 2520 adjusts the magnification to the scan controller 6 representing the X-axis position.
The servo drive unit 254 receives a signal from 8 and continuously changes it.

With variations in zoom lens 2520 magnification relative to the X-axis displacement of photographic image 64, individual detector elements of detector array 256 move in the X-axis scan direction and zoom lens 252
Depending on the direction of the zero magnification change, image areas on the photographic image can be detected along converging or diverging lines.

Electrons are used to cause individual elements in the detector array 256 to generate image data along the Ebi-polar lines, thereby allowing multiple Ebi-polar lines to be scanned simultaneously during a single scan along the Y axis. As the optical and electro-optical elements, currently known ones can be used, and those skilled in the art can easily select what kind of elements to use.

If the memory TO is of the analog type, the analog signal from each detector element is input directly to the analog memory together with the signal representative of the scan position from the scan controller.

However, if the detector is in the form of an integrated linear array,
And when the light source is pulsed, the scan controller 68 sequentially generates trigger and read signals at predetermined intervals representing predetermined distances along the X-axis.

A trigger signal on line 258 is applied to light source 206;
The readout signal on line 260 is then transmitted to detector array 256.
is applied to

The signals from the individual elements are applied to a storage device TO, where signals from predetermined elements are selected and combined with appropriate digital address signals generated by controller 68 to address the predetermined address. stored in order.

A digital address signal is sent from controller 68 to storage TO via line 262.

As discussed with respect to FIG. 5, the scanning of multiple lines on either side of each scanned Ebipolar line to eliminate residual parallax in the direction across the Ebipolar line is also accomplished in the embodiment of FIG. It is obvious that it can be done.

Lines 246', 248' and 250' are shown emanating from either side of the epipolar line shown at points 246, 248 and 250.

However, in the embodiment of FIG. 6, the alternating scanned lines 246', 248' and 250' are not parallel to the scanned epipolar lines, but have a sector pattern of epipolar lines. There is.

In addition, the specific example in Fig. 6 has three epipolar structures as shown in the figure.
The present invention is not limited to scanning along a line, and a plurality of epipolar lines may be scanned during each X-axis direction scan.

The storage device TO shown in FIG. 1 may be of the analog or digital type, although the latter is preferred.

Generation of digital data from a linear array of charge-coupled or packet brigade devices is the sixth step.
This can be achieved as discussed with reference to the figures.

However, analog data from analog detectors can be converted to digital data using methods well known in the art.

FIG. 1 illustrates one method of performing this conversion.

Photographic image 64 is mechanically scanned along the X-axis by servo drive 62 in response to signals from scan controller 68 .

As the photographic image moves relative to the microdensitometer, which consists of an input 202 and a detector 204, the detector generates an analog electrical signal representative of the image area on the photographic image being scanned.

This analog electrical signal is amplified by amplifier 402, and the amplified signal is input to analog-to-digital converter 404.

Simultaneously with the generation of drive signals for servo drive 62, the scan controller generates sampling signals at predetermined intervals representing a predetermined distance of movement of image 64 along the X-axis.

The sampled signal is sent via line 406 to an analog-to-digital converter 404, which samples the analog signal at predetermined intervals.

The analog signal samples thus obtained are then digitized using well known methods.

The digitized sample signals are then sequentially entered into a storage interface device, such as a shift register, where the digitized sample signals are temporarily stored until the scan is completed.

Upon completion of the scan, scan controller 68 issues a command signal on line 410 which causes the interface device to output a block of digital data with an appropriate address, as is common practice in the art. Occur.

Electronic circuits that perform the operations described above are well known in the art and therefore need not be described in detail.

[Brief explanation of the drawing]

1 is a perspective view of a preferred embodiment of a single-picture epipolar scanning device according to the invention; FIG. 2 is a schematic diagram for explaining the epipolar principle; and FIG. 3 is a single-picture epipolar scanning device with a rotating stage. FIG. 4 is a perspective view showing another specific example of the scanning device;
5 is a schematic diagram showing the components of another embodiment of a micro densitometer having a linear array of detection elements; FIG. 6 is a diagram showing the components of a microdensitometer and a microscope; FIG. 7 is a schematic diagram illustrating another embodiment of a microdensitometer capable of scanning multiple epipolar lines during a vertical translational motion, and FIG. It is a flowchart which shows. 12...Stage, 14...Base, 1
6, 20... Carriage, 42, 62...
... Servo drive device, 64 ... Photographic image, 300
...Microscope, 68...Scanning control device,
TO... Storage device, T2... Rotating carriage, 92... Servo drive device, 200...
...Micro densitometer, 206...Light source, 2
04...Detector, 304...Beam
Splitter, 302... Matching lamp, 222
...Slit opening, 23B. 240.242...detection element, 254...
...Servo drive unit, 252...Zoom lens, 402...Amplifier.

Claims (1)

[Scope of Claims] 1. A scanning device of the type that generates image data along an Epipolar line from a single photographic image and stores the image data for subsequent data processing and ground preparation. a stage having a base and a pair of carriages mounted on the base and each movable relative to the base along two mutually perpendicular axes, the stage being configured to move the photographic image; and is adapted to translate the photographic image along the mutually perpendicular axes, and is affixed to the base for detecting image details within a predetermined area on the photographic image. a microdensitometer for generating electrical signals representative of detected image details; and actuating the stage to translate the photographic image relative to the microdensitometer, thereby causing the microdensitometer to move; a control means for generating an electrical signal representative of image details along a predetermined set of epipolar lines on a photographic image; and a storage device for storing the electrical signal generated by the microdensitometer; a micro-densitometer is rigidly attached to said base and includes optical means positioned in one corner of said photographic image for illuminating said predetermined area on said photographic image with light; rigidly attached to the stand and positioned on the other side of the photographic image for detecting light modulated in the image area within the predetermined area and generating an electrical signal representative of the intensity of the detected light; detection means, the optical means projecting onto the photographic image a narrow slit of light located along one of the mutually perpendicular axes, and the detection means is arranged parallel to the slit of light. a linear array of detection elements, one of said detection elements being adapted to receive light transmitted through the photographic image from a small portion of the slit line representing said evipolar line during scanning translation across said slit image; , the other detection elements of the linear detection element array are arranged to receive other portions of the photographic image transmission slit light image representing a line displaced a predetermined distance parallel to the Ebipolar line; Accordingly, the scanning device is characterized in that image data is generated along the Epolar line and lines located parallel to both sides thereof, and residual parallax is removed during subsequent data processing. 2. In the scanning device according to 1 above, a part of the photographic image in the immediate vicinity of the predetermined area detected by the micro densitometer is visually observed, and the area detected by the micro densitometer is detected by the micro densitometer. A scanning device comprising a microscope fixed to said base to enable alignment of the photographic image to the area. 3. The scanning device according to item 1 above, wherein the stage further includes a rotatable photographic carrier, and the control means also rotates the photographic image in a plane parallel to mutually perpendicular axes. A scanning device characterized in that it operates.