JP3207209B2 - Tilt image correction processor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus having a function of automatically correcting the inclination of an image projected on a microfilm to obtain an erect image. The present invention relates to a tilt image correction processing device having a function of automatically determining.

[0002]

2. Description of the Related Art Recently, for example, in an image processing apparatus for automatically digitizing image information printed on a microfilm or the like and inputting it to an optical disk or copying the image information, the image information is printed. In some cases, the inclination of image information is automatically corrected. In other words, image information is usually imprinted on a microfilm so as to be an erect image, but not limited to this, there are some images that are imprinted I do. If the image information is imprinted with an inclination as described above, it is necessary to correct the inclination when inputting or copying an erect image to an optical disk or the like. The correction of the inclination is automatically performed without manual operation. By performing such a correction, the inclination of the image information to a certain degree is automatically corrected, and input or copying as an erect image is enabled.

[0003]

However, in the conventional image processing apparatus which automatically corrects the inclination of the image information, it is very difficult to always input an erect image. Although it can be said that it is convenient,
Since the correction is always performed irrespective of whether the image information is inclined or not, there is a problem that it takes a relatively long time to input the image information or the like, that is, the productivity is reduced. Further, depending on the density and the shape of the image information, there may be a problem that the quality of the image is deteriorated by executing the correction. The present invention has been made in view of such a conventional problem, and solves the above problem by providing a function of determining whether or not to perform inclination correction of target image information. It is an object to provide a tilted image correction processing device.

[0004]

To achieve the above object, the present invention provides a projecting means for projecting a document image on an image receiving unit, a detecting means for detecting an inclination between the document image and the image receiving unit. a correction means for correcting the inclination of the image receiving unit and the original image in accordance with the detection result by the detection means, before
By determining whether the original image is rectangular or not,
Te, and a determination means for determining whether to perform the correction by said correcting means, be detected inclination between the image receptor and the original image by said detecting means, the correction by the determination means When it is determined that the correction is not performed, the correction by the correction unit is not performed.

[0005] The determination as to whether or not this is a rectangle is performed by calculating the inclination between the original image and the image receiving portion at a plurality of locations in the original image, and when the difference between the calculated inclinations is equal to or smaller than a predetermined value,
It is characterized in that it is determined that the document image is rectangular, or that vertices of the document image are detected, and when the detected vertices are at four places, it is determined that the document image is rectangular. Further, according to the present invention for achieving the above object, there is provided an input unit for inputting image information, a detecting unit for detecting a tilt of the image information input to the input unit, and a detecting unit for detecting an inclination of the image information. Correction means for correcting the inclination of the image information, and whether or not the image information is rectangular
And determining means for determining whether or not to execute the correction by the correction means , even if the inclination of the image information is detected by the detection means,
When it is determined that the correction is not performed by the determination unit, the correction by the correction unit is not performed.

[0006]

With this configuration, the correcting means corrects the inclination of the original image and the image receiving section detected by the detecting means based on the inclination. The determining means determines whether or not to perform the correction by the correcting means. Therefore, the skew correction is performed only for the image information that truly requires skew correction, thereby improving productivity and preventing malfunction.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an external view of a micro image processing apparatus incorporating a tilt image correction processing apparatus according to the present invention.
2 is a schematic configuration diagram of an optical path system of the device shown in FIG.

[0008] The micro-image processing apparatus 10 transmits image information imprinted on a micro-film to a screen 11.
It has two functions, a function as a reader for enlarging and projecting the image and a function as a printer for copying the image information. LE provided at the lower left of screen 11
D12 indicates whether or not automatic tilt correction has been performed. Various operation switches are provided on an operation unit 13 provided below the screen 11.
The print button 14 is a switch used when copying the image information, and the correction mode button 15 is a switch for specifying whether or not to execute automatic tilt correction. When the correction mode button 15 is turned on, a mode is set in which automatic tilt correction is executed. At this time, the LED 12 lights up,
Indicates that the mode is a mode in which the automatic tilt correction is executed.

An optical path system for outputting the image information to the screen 11 or to a printer (not shown) is configured as shown in FIG. 2, and projects the image information as follows. The light from the light source 20 is condensed by the condenser lens 21, irradiates and passes through the microfilm F loaded in the carrier (not shown), and reaches the projection lens 22. Thereafter, the light passes through the inclination correcting prism 23. Thus, the image projection optical path A
Is formed. When the optical path switching mirror 25 is at the retracted position shown by the dotted line in the drawing, that is, when it functions as a reader, a reader optical path A1 is formed in which the light that has passed through the correction prism 23 travels from the fixed mirror 24 to the reader mirror 26. The light bent by the reader mirror 26 reaches the screen 11,
The image information projected on the microfilm F is enlarged and projected. The first scan mirror 27 and the second scan mirror 28, which will be described later, are both in the retracted position at the right end in the drawing when the leader optical path A1 in which the optical path switching mirror 25 is in the retracted position is formed.

On the other hand, when the optical path switching mirror 25 is at the position indicated by the solid line in the drawing, that is, when it functions as a printer, light passing through the correction prism 23 is transmitted from the fixed mirror 24 to the optical path switching mirror 25 and the first scan mirror 2.
A reading optical path A2 extending to the CCD line sensor L via the seventh and second scan mirrors 28 is formed. When the operation of causing the CCD line sensor L to read the image information of the microfilm is started, first, the optical path switching mirror 25 slides from the retracted position to the operating position indicated by the solid line in the drawing, and at the same time, the first scan mirror 27 and the The second scan mirror 28 is prescanned from the retracted position in conjunction with the left end position indicated by the solid line in the drawing. The optical path switching mirror 25 stops at the operating position, and the first scan mirror 27 and the second scan mirror 28 scan and move from the left end position to the retracted position. Therefore, the light reflected from the fixed mirror 24 is
The light is reflected by the optical path switching mirror 25 and is guided to the CCD line sensor L via the first scanning mirror 27 and the second reflecting mirror 28 which are scanningly moving. As a result, the image information of the microfilm F is projected and exposed on the CCD line sensor L and read. The image signal photoelectrically converted by the CCD line sensor L is input to a laser printer or the like, and copying, display, and the like are performed based on the image signal.

When the above operation is completed, the optical path switching mirror 25, the first scan mirror 27 and the second scan mirror 28 return to the retracted positions, respectively, and the image information of the microfilm F is projected on the screen 11 again. become.

FIG. 3 is a block diagram of a control system of the tilt image correction processing device according to the present invention. The operation panel 13 is provided with a print button 14 and a correction mode button 15 as shown in FIG.
Input to 0. A clock signal of a predetermined frequency is output from the clock generation circuit 31, and this clock signal is
It is provided to the PU 30 and the CCD line sensor L. A / D
The converter 32 performs CC scanning by mirror scanning as described above.
The image information of the microfilm F captured as an analog electric signal by the D line sensor L is converted into a digital image signal based on a conversion signal from the CPU 30. The converted digital image signal is transmitted to the shading circuit 33. The shading signal input and output from the CPU 30 is converted into a grayscale image signal for forming a grayscale image. This grayscale image signal is input to the comparison circuit 34. The threshold matrix storage unit 35 stores a plurality of reference densities for the gray scale comparison in the comparison circuit 34. The reference density used in the comparison circuit 34 is selected based on a threshold matrix selection signal output from the CPU 30, and the selected threshold matrix is used as a threshold signal in the comparison circuit 34.
Will be given to The selection output circuit 36 includes a CPU
The binarized image signal is selectively output based on the effective image signal output from the output terminal 30. Image memory unit 37
Stores the image signal output from the selection output circuit 36 and outputs it to the CPU 30 as an image signal. CPU3
0 indicates that the image signal output from the image memory unit 37 is
The calculation is performed based on the program stored in the EPROM 38 to determine the inclination correction and whether or not to perform the correction. While the CPU 30 outputs a prism rotation signal for rotating the prism for adjusting the tilt of the image, the CPU 30 receives a fixed position signal of the prism. The EPROM 38 stores a program for tilt correction described later and a determination as to whether or not to perform the correction.
Are for temporarily storing the calculation results and the like when performing various processes. Also, the DIP switch 40
This is a switch used in an operation mode of the micro image processing apparatus, for example, when an operation is performed in accordance with a difference in the type of micro film to be loaded.

Next, the general operation of the inclination correction processing device according to the present invention will be described with reference to the flowchart of FIG. After the microfilm F is loaded into the micro image processing apparatus 10 and the reading operation is completed, the print button 14 is turned on to start the reading operation. By the start of this reading operation, a preliminary photometric scan for determining whether or not to perform tilt correction is started (S1). The image information input to the CCD line sensor L by the preliminary photometric scan is stored in the image memory unit 37 via the above-described A / D converter 32, shading circuit 33, comparison circuit 34, and selection output circuit 35 ( S2). And
The CPU 30 determines whether or not the inclination correction should be automatically performed based on the image signal stored in the image memory unit 37. When the processing of this step is performed, the subroutine flowchart shown in FIG. 5 or FIG. 7 is processed (S3). When it is determined that the inclination is to be corrected as a result of this determination, L
The ED 12 is turned on to perform an automatic tilt correction process. That is, by rotating the correction prism 23 about the optical axis, the image information projected on the microfilm F is projected straight to the CCD line sensor L. On the other hand, when it is determined that the inclination correction is not performed, the process proceeds to the next step without performing the automatic inclination processing. When it is determined that the automatic inclination correction process is not performed, the LED 12 is turned off (S3, S3
4). After the above processing is performed, a main scan is performed, and image information obtained by the CCD line sensor L by this scan is output to an external device such as a laser beam printer (S5, S6). As described above, when it is determined that the inclination correction is not automatically performed, the LED 12
Is turned off and the operator is notified of this, and the main scan is performed without performing tilt correction. On the other hand, when it is determined that the inclination correction is automatically performed, L
The main scan is performed after the ED 12 is turned on and the inclination correction is automatically performed.

The flowchart shown in FIG. 5 is a subroutine flowchart showing a process for determining whether or not to perform inclination correction, which is performed in step S3 of the flowchart shown in FIG. The operation of this flowchart will be described with reference to FIG. As shown in FIG.
It is assumed that the image information 40 is photographed at an angle as shown in FIG. In general, it is considered that there is almost no image that is extremely inclined as described above, but this is done to facilitate understanding of the invention. Also,
The image information 40 is white in comparison with the surroundings in the case of a positive film, and black in comparison with the surroundings in the case of a negative film. It can be determined whether or not to perform the processing.

First, based on the image information stored in the image memory section 37, the CPU 30 determines a point A at which the data constituting the image information changes from black to white or from white to black.
i and Bi (i = 1 to n) are searched. That is, image information 4
A contour line of 0 is searched (S10). Next, the distances Xi, Yi in the X and Y directions between any two points among the obtained points Ai and Bi (i = 1 to n) (i =
1 to n). For example, distances X1, Y1 in the X and Y directions at two points A1, B1 in FIG. 6, or two points Ai, Bi
Then, the distances Xi and Yi in the X and Y directions are calculated (S11). The inclination θi (i = 1 to n) of the line connecting any two points obtained by the above processing is obtained. In the above example, the inclination θ1 of the line connecting the two points A1 and B1
Or the gradient .theta.i of a line connecting the two points Ai and Bi (S12). Next, it is determined whether or not the difference between the respective inclinations θi (i = 1 to n) obtained in step S12 is sufficiently small. That is, it is determined whether the difference between the inclination θ1 and the inclination θi is sufficiently small (S13). When it is determined that the difference is sufficiently small, it is determined that the input image is a rectangular image that can be subjected to the inclination correction processing,
Tilt correction for outputting the image as an erect image to an external device is performed. Specifically, the amount of rotation of the correction prism 23 is calculated, and the amount of rotation is calculated based on the inclination θ of all the points obtained in step S12.
It is 1/2 of the average value of 1 to .theta.n (S14). CPU3
0 outputs a prism rotation signal based on the calculation result, and drives the correction prism 23 to rotate while inputting a fixed position signal (S15). If it is determined in step S13 that the difference is not sufficiently small, the LED 12 is turned off, a message is displayed indicating that the inclination correction process is not to be performed automatically, and the process returns to the flowchart of FIG. Scan is to be executed (S1
6). In the above processing, a large number of points at which the data constituting the image information changes from black to white or from white to black are searched, and the inclination of the image information is calculated based on the result. Therefore, if there is no problem in the calculation, the number of points to be searched may be reduced to some extent.

The flowchart shown in FIG. 7 is a subroutine flowchart showing another process for determining whether or not to perform inclination correction. The operation of this flowchart will be described with reference to FIG. First, C
Based on the image information stored in the image memory unit 37, the PU 30 determines that the data constituting the image information is black-white-
A line that changes to black or white-black-white is searched in the vertical and horizontal directions as shown in FIG. 8, and a point at which the change distance is the minimum, that is, a minimum point is obtained. By this search, the vertices of the image information, for example, the points P1 and P2 in FIG. 8, are obtained. This is because the change distance between the black-and-white and black-and-white or white-and-white is minimum at the top (S2
0). If there are four minimum points detected by the above search, it is determined that the input image is a rectangular image that can be subjected to the inclination correction process, and the average of the inclination of the image information is calculated from the obtained coordinates of the vertices. Then, inclination correction for outputting the image as an erect image to an external device is performed. Specifically, the amount of rotation of the correction prism 23 is calculated, and the amount of rotation is １ ／ of the inclination obtained in step S22 (S21 to S23). CPU 30
Outputs a prism rotation signal based on the calculation result,
The correction prism 23 is driven to rotate while inputting the home position signal (S24). If the number of the minimum points is not four, that is, three or less or five or more in the determination in the step of S21, the LED 12 is turned off and a message indicating that the inclination correction process is not automatically performed is displayed.
Returning to the processing of the flowchart in (1), the main scan is executed (S25).

In the above embodiment, the micro image processing apparatus for reading the image information imprinted on the micro film has been described as an example. However, the present invention is not limited to this, and the present invention is not limited to this. The present invention is also applicable to an image scanner or a copying machine. Also, an example in which the inclination is corrected optically using a correction prism has been described, but electrically, for example,
The image information is stored in the frame memory while being tilted, and the tilt is corrected by the read address at the time of reading, or the tilt is corrected by addressing the write address when writing the image information to the frame memory. You may do it. Further, the microfilm may be rotated while the optical system is fixed, or the inclination may be corrected by rotating the CCD line sensor L. In addition, a mode in which the tilt is automatically and uniformly corrected for any image information, and a mode in which the tilt is automatically determined after automatically determining whether to perform the correction as in the present embodiment. May be selectable. Further, according to whether the image information is a negative image or a positive image, a mode for selecting a program for determining whether the image is tilted is provided,
It is also conceivable to improve the reliability of the judgment. According to the device of the present invention operating as described above,
(1) It is possible to prevent a malfunction such as correcting the inclination of an image that is not a rectangle. (2) Since it is automatically determined that the tilt correction is not performed, the operation in which the operator operates the correction mode button 15 to release the correction mode and read the image again can be omitted. (3) LED12
Thus, whether or not to perform automatic tilt correction can be notified. (4) Various effects such as improvement of an editing processing function such as automatic black frame erasure can be obtained.

[0018]

As described above, according to the present invention, since the function of determining whether or not to perform the inclination correction of the target image information is provided, the time required for image processing can be reduced. Can be achieved, and furthermore,
A malfunction such as correcting an inappropriate image can also be prevented.

[Brief description of the drawings]

FIG. 1 is an external view of a micro image processing apparatus including a tilt image correction processing apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram of an optical path system of the device shown in FIG.

FIG. 3 is a block diagram of a control system of the tilt image correction processing device according to the present invention.

FIG. 4 is a main flowchart of the tilt image correction processing device according to the present invention.

FIG. 5 is a subroutine flowchart for determining whether to execute tilt correction in the tilt image correction processing device according to the present invention.

FIG. 6 is a diagram for explaining a calculation process of the flowchart shown in FIG. 5;

FIG. 7 is a subroutine flowchart showing another process for determining whether or not to execute tilt correction in the tilt image correction processing device according to the present invention.

FIG. 8 is a diagram for explaining a calculation process of the flowchart shown in FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Micro image processing apparatus 11 ... Screen 12 ... LED 13 ... Operation panel 14 ... Print button 15 ... Correction mode button 20 ... Light source 23 ... Correction prism L ... CCD line sensor 30 ... CPU 37 ... Image memory part

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-10144 (JP, A) JP-A-62-251736 (JP, A) JP-A-62-293880 (JP, A) JP-A-2- 130550 (JP, A) JP-A-2-146572 (JP, A) JP-A-2-102470 (JP, A)

Claims (4)

(57) [Claims] A projection unit configured to project an original image onto an image receiving unit; a detecting unit configured to detect an inclination between the original image and the image receiving unit; Correcting means for correcting the inclination with respect to the image receiving portion; and determining whether or not the document image is rectangular.
Te, and a determination means for determining whether to perform the correction by said correcting means, be detected inclination between the image receptor and the original image by said detecting means, the correction by the determination means A tilt image correction processing device, wherein when it is determined that the correction is not performed, the correction by the correction unit is not performed. 2. The method according to claim 1, wherein the determining unit calculates the inclination between the document image and the image receiving unit at a plurality of locations on the document image, and when the calculated difference between the inclinations is equal to or less than a predetermined value, the document image is rectangular. The tilt image correction processing apparatus according to claim 1 , wherein the inclination image correction processing apparatus determines that the tilt angle is equal to or smaller than the angle. Wherein said determining means, said detecting the vertices of the original image, when the vertex was the detection of positions 4, claim 1 Symbol, wherein the original image is determined to be a rectangle
A mounted tilt image correction processing device. 4. An input unit for inputting image information, a detecting unit for detecting a tilt of the image information input to the input unit, and correcting the tilt of the image information according to a detection result by the detecting unit. Correcting means and determining whether the image information is rectangular or not.
A determination unit that determines whether or not the correction is to be performed by the correction unit. Even if the inclination of the image information is detected by the detection unit, the determination unit determines that the correction is not to be performed. Wherein the correction by the correction means is not performed when the error occurs.