JPH04271337A - Tilt image correction processor - Google Patents

Abstract

PURPOSE:To offer a tilt image correction processor provided with a function for automatically judging whether or not the tilt of image information is corrected in the case that the inputted image information is tilted. CONSTITUTION:A CPU 30 is decided whether or not the image information inputted in an image memory part 37 is tilted, and further it decides whether or not the correction of the tilt of the image is executed. Therefore, efficiency for processing the image information is enhanced and a malfunction in the case of executing the correction of the tilt is prevented.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is an image processing apparatus having a function of automatically correcting the tilt of an image imprinted on a microfilm to make an erect image. The present invention relates to a tilt image correction processing device having a function of automatically determining.

0002

[Prior Art] Recently, image processing devices that automatically digitize image information imprinted on microfilm, etc., input it to an optical disk, etc., or copy the image information, etc. There is a system that automatically corrects the tilt of image information. In other words, image information is usually imprinted on microfilm so that it is an upright image, but there are some images that are imprinted at an angle. do. If the image information is imprinted at an angle in this manner, it is necessary to correct the inclination each time when attempting to input or copy onto an optical disk or the like as an erect image. This tilt correction is automatically performed without manual intervention. By performing such correction, the tilt of the image information is automatically corrected to a certain extent, making it possible to input or copy the image as an erect image.

0003

[Problems to be Solved by the Invention] However, in conventional image processing devices that automatically correct the tilt of image information, it is difficult to always input an erect image. Although it can be said that it is convenient for
Since the correction is always performed regardless of whether the image information is tilted or not, there is a problem that it takes a relatively long time to input the image information, that is, productivity decreases. Further, depending on the density and shape of the image information, the execution of the correction may actually cause problems such as deterioration of the image quality. The present invention was developed in view of these conventional problems, and solves the above problems by providing a function to determine whether or not to perform tilt correction on target image information. The purpose of the present invention is to provide a tilted image correction processing device.

0004

[Means for Solving the Problems] To achieve the above object, the present invention includes a projection means for projecting an original image onto an image receiving section, a detecting means for detecting the inclination of the original image and the image receiving section. , comprising a correction means for correcting the inclination of the original image and the image receiving section according to a detection result by the detection means, and a determination means for determining whether or not the correction is to be performed by the correction means. do.

[0005] The determining means is characterized in that it determines whether or not the document image is rectangular. This determination of whether or not the original image is a rectangle is made by calculating the inclinations between the original image and the image receiving section at multiple locations on the original image, and if the difference between the calculated inclinations is less than a predetermined value, the original image is determining that it is a rectangle, or detecting the apex of the document image;
The present invention is characterized in that when there are four detected vertices, it is determined that the document image is rectangular.

[0006]

[Operation] With this structure, the correction means corrects the inclination based on the inclination of the original image detected by the detection means and the image receiving section. The determining means determines whether or not the correction by the correcting means is to be performed. Therefore, tilt correction is performed only on image information that truly requires tilt correction, thereby improving productivity and preventing malfunctions.

[0007]

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

[0008] The micro image processing device 10 has a screen 11 for transmitting image information imprinted on the micro film.
It has two functions: a reader function for enlarging and projecting image information, and a printer function for copying the image information. LE provided at the bottom left of screen 11
D12 displays whether or not automatic tilt correction is being executed. Further, the operation section 13 provided at the bottom of the screen 11 is provided with various operation switches. 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 perform automatic tilt correction. When this correction mode button 15 is turned on, a mode is set in which automatic tilt correction is executed. At this time, LED 12 lights up,
Indicates the mode in which automatic tilt correction is executed.

The optical path system for outputting this image information to the screen 11 or to a printer (not shown) is constructed as shown in FIG. 2, and the image information is projected in the following manner. The light from the light source 20 is condensed by a condenser lens 21, then irradiates and passes through a microfilm F loaded in a carrier (not shown), and reaches the projection lens 22. Thereafter, it passes through a tilt correction prism 23. In this way, the image projection optical path A
is formed. When the optical path switching mirror 25 is in the retracted position indicated by the dotted line in the figure, that is, when it functions as a reader, a reader optical path A1 is formed in which light passing through the correction prism 23 extends from the fixed mirror 24 to the reader mirror 26. The light bent by the leader mirror 26 reaches the screen 11,
The image information imprinted on the microfilm F is enlarged and projected. Note that a first scan mirror 27 and a second scan mirror 28, which will be described later, are both in the retracted position at the right end in the figure when the leader optical path A1 is formed in which the optical path switching mirror 25 is in the retracted position.

On the other hand, when the optical path switching mirror 25 is at the solid line position shown in the figure, that is, when it functions as a printer, the light that has passed through the correction prism 23 is transferred from the fixed mirror 24 to the optical path switching mirror 25 and the first scan mirror 2.
7 and the second scan mirror 28, a reading optical path A2 is formed which reaches the CCD line sensor L. 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 shown by the solid line in the figure, and at the same time, the first scanning mirror 27 and The second scan mirror 28 is preliminarily scanned from the retracted position to the left end position indicated by the solid line in the figure. The optical path switching mirror 25 stops at the operating position, and the first scan mirror 27 and the second scan mirror 28 interlock and scan from the left end position to the retracted position. Therefore, the light reflected by the fixed mirror 24 is
The light is reflected by the optical path switching mirror 25 and 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 on the microfilm F is projected onto the CCD line sensor L and is read. The image signal photoelectrically converted by this CCD line sensor L is input to a laser printer or the like, and copying, display, etc. are performed based on this image signal.

When the above operations are completed, the optical path switching mirror 25, the first scanning mirror 27, and the second scanning mirror 28 return to their respective retracted positions, and the image information of the microfilm F is projected onto the screen 11 again. become.

FIG. 3 is a block diagram of the control system of the tilted image correction processing apparatus according to the present invention. As shown in FIG. 1, the operation panel 13 has a print button 14 and a correction mode button 1.
5 are provided, and signals from these are sent to the CPU 30.
is input. A clock signal of a predetermined frequency is output from the clock generation circuit 31, and this clock signal is
It is applied to U30 and CCD line sensor L. A/D
Transducer 32 converts C by mirror scanning as described above.
The image information of the microfilm F captured by the CD line sensor L as an analog electrical signal is converted into a digital image signal based on a conversion signal from the CPU 30, and this converted digital image signal is sent to the shading circuit 33. Based on the input shading signal output from the CPU 30, it is converted into a grayscale image signal for forming a grayscale image. This grayscale image signal is sent to the comparator circuit 34.
will be entered into. Threshold matrix storage unit 35
A plurality of reference densities are stored in the comparison circuit 34 for comparison of gradations. The reference density used in the comparison circuit 34 is selected based on a threshold matrix selection signal output from the CPU 30, and this selected threshold matrix is used as a threshold signal in the comparison circuit 3.
It will be given to 4. The selection output circuit 36
A binarized image signal is selectively output based on the effective image signal output from U30. Image memory section 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 is the image signal output from the image memory section 37,
Calculations are made based on the program stored in the EPROM 38 to determine whether or not to correct the tilt. The CPU 30 outputs a prism rotation signal for rotating a prism for adjusting the inclination of an image, while a fixed position signal of the prism is input to the CPU 30. Note that the EPROM 38 stores a program for tilt correction, which will be described later, and for determining whether or not to perform the correction.
It is used to temporarily store calculation results when performing various processes. Further, the DIP switch 40 is
This switch is used to operate the micro image processing device in accordance with the operating mode, for example, depending on the type of microfilm loaded.

Next, the general operation of the tilt correction processing apparatus according to the present invention will be explained based on the flowchart shown in FIG. After loading the microfilm F into the micro image processing device 10 and completing the reading operation, the print button 14 is turned on to start the reading operation. With 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 this preliminary photometric scan is stored in the image memory section 37 via the A/D converter 32, shading circuit 33, comparison circuit 34, and selection output circuit 35 ( S2). and,
Based on the image signal stored in the image memory section 37, the CPU 30 determines whether or not tilt correction should be performed automatically. Note that when this step is performed, the subroutine flowchart shown in FIG. 5 or 7 is processed (S3). As a result of this judgment, when it is determined that the tilt correction is to be performed, the L
The ED 12 is turned on to perform automatic tilt correction processing. That is, by rotating the correction prism 23 about the optical axis, the image information imprinted on the microfilm F is projected straight onto the CCD line sensor L. On the other hand, if it is determined not to perform tilt correction, the process proceeds to the next step without performing this automatic tilt processing. Note that when it is determined that automatic tilt correction processing is not to be performed, the LED 12 turns off (S3, S
4). After the above processing is executed, a main scan is performed, and the 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). In this manner, when it is determined that the tilt correction is not to be performed automatically, the LED 12 is turned off to notify the operator of this fact, and the main scan is performed without performing the tilt correction. On the other hand, if it is determined that the tilt correction is to be performed automatically, the LE
The main scan will be performed after turning on D12 and automatically performing tilt correction.

The flowchart shown in FIG. 5 is a subroutine flowchart showing a process for determining whether or not to perform tilt correction, and is carried out in step S3 of the flowchart shown in FIG. Note that the operation of this flowchart will be explained with reference to FIG. As shown in Figure 6, microfilm F
Assume that the image information 40 is tilted as shown in the figure. It should be noted that normally, it is thought that there are almost no images that are imprinted at an extreme inclination like this, but the reason for doing so is to make the invention easier to understand. Also,
In the case of a positive film, the image information 40 is white compared to the surroundings, and in the case of a negative film, it is black compared to the surroundings, but in the present invention, tilt correction can be applied to any film. It is possible to judge whether or not to perform 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.
Search for i, Bi (i=1 to n). In other words,
The outline of the image information 40 will be searched (S10)
. Next, the above-determined points Ai, Bi (i=1
~n) Find the distances Xi, Yi (i=1~n) in the X and Y directions between any two points at each point. For example, the distances X1 and Y1 in the X and Y directions at the two points A1 and B1 in FIG. 6, or the distances Xi and Yi in the X and Y directions at the two points Ai and Bi in FIG.
11). The slope θi (i=1 to n) of a line connecting any two points determined by the above processing is determined. In the above example, the slope θ1 of the line segment connecting the two points A1 and B1 or the slope θi of the line segment connecting the two points Ai and Bi are determined (S12). Next, it is determined whether the difference between the respective slopes θi (i=1 to n) obtained in step S12 is sufficiently small. That is, it is determined whether the difference between the slope θ1 and the slope θi is sufficiently small (S13). When the difference is determined to be sufficiently small, it is determined that the input image is a rectangular image that can be processed for tilt correction, and tilt correction is performed to output the image to an external device as an erect image. . Specifically, the amount of rotation of the correction prism 23 is calculated, and this amount of rotation is 1 of the average value of the slopes θ1 to θn for all the points found in step S12.
/2 (S14). The CPU 30 outputs a prism rotation signal based on this calculation result, and rotates the correction prism 23 while inputting the fixed position signal (S15).
. If it is determined in step S13 that the difference is not small enough, the LED 12 is turned off to display that the tilt correction process will not be performed automatically, and the process returns to the flowchart in FIG. A scan will be executed (S16). In the above processing, the data forming the image information is searched for many points where it changes from black to white or from white to black, and the slope of the image information is calculated based on the results. Therefore, if there is no problem with 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 tilt correction. Note that the operation of this flowchart will be explained with reference to FIG. First, C
Based on the image information stored in the image memory section 37, the PU 30 determines whether the data constituting the image information is black, white, or black.
A line that changes to black or white to black to white is searched for in the vertical and horizontal directions as shown in FIG. 8, and the point where the distance of the change is the smallest, that is, the minimum point, is found. Through this search, the vertices of the image information, for example, points P1 and P2 in FIG. 8, are found. This is because at the vertex, the distance of change between black and white or black and white is the minimum (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 tilt correction processing, and the average slope of the image information is calculated from the coordinates of each of the obtained vertices. Then, tilt correction is performed to output the image to an external device as an erect image. Specifically, the amount of rotation of the correction prism 23 is calculated, and this amount of rotation is 1/2 of the inclination determined in step S22 (S21 to S23). CPU30
outputs a prism rotation signal based on this calculation result,
The correction prism 23 is rotationally driven while inputting the fixed position signal (S24). In the judgment in step S21, if there are not four minimum points, that is, three or less or five or more, the LED 12 is turned off to display that the tilt correction process will not be performed automatically, and the process shown in FIG.
Returning to the process of the flowchart, the main scan is executed (S25).

In the above embodiments, a micro image processing device that reads image information imprinted on a microfilm has been described as an example, but the present invention is not limited to this, and can be used to read general original images. It can also be applied to things like image scanners or copying machines. In addition, although we have shown an example in which the tilt is corrected optically using a correction prism, it is also possible to correct the inclination electrically, for example.
It is possible to store image information in the frame memory as it is tilted and correct the tilt using the read address when reading it out, or to correct the tilt by addressing the write address when writing the image information to the frame memory. You can also do it. Furthermore, the microfilm may be rotated with the optical system fixed, or the CCD line sensor L may be rotated to correct its inclination. Furthermore, there is a mode in which tilt correction is automatically performed uniformly on any image information, and a mode in which tilt correction is automatically performed after automatically determining whether or not to perform the correction, as in this embodiment. You may also be able to select. Furthermore, a mode is provided for selecting a program for determining whether or not the image is tilted depending on whether the image information is a negative image or a positive image.
It is also possible to improve the reliability of the judgment. According to the device of the present invention that operates as described above, (
1) It is possible to prevent malfunctions such as correcting the tilt of non-rectangular images. (2) Since it is automatically determined that tilt correction is not to be performed, the operator does not have to operate the correction mode button 15 to cancel the correction mode and read the image again. (3)
The LED 12 can inform whether automatic tilt correction is to be performed or not. (4) Various effects can be produced, such as improved editing processing functions such as automatic black frame erasure.

[0018]

[Effects of the Invention] As described above, according to the present invention, the time required for image processing is reduced because the present invention has a function to determine whether or not to perform tilt correction on target image information. In addition,
It is also possible to prevent malfunctions such as correcting inappropriate images.

[Brief explanation of the drawing]

FIG. 1 is an external view of a micro image processing device incorporating a tilted image correction processing device according to the present invention.

FIG. 2 is a schematic configuration diagram of an optical path system of the apparatus shown in FIG. 1.

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

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

FIG. 5 is a subroutine flowchart for determining whether or not to perform tilt correction in the tilt image correction processing device according to the present invention.

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

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

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

[Explanation of symbols]

10...Micro image processing device 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 section

Claims (4)

[Claims] 1. Projection means for projecting a document image onto an image receiving section; detecting means for detecting the inclination of the document image and the image receiving section; A tilted image correction processing device comprising a correction means for correcting the tilt with respect to an image receiving section, and a determination means for determining whether or not the correction is to be performed by the correction means. 2. The tilted image correction processing apparatus according to claim 1, wherein the determining means determines whether or not the document image is rectangular. 3. The determining means calculates a tilt between the document image and the image receiving section at a plurality of locations on the document image, and if the difference between the calculated tilts is equal to or less than a predetermined value, the document image is rectangular. Claim 2 characterized in that it is determined that
The tilted image correction processing device described in . 4. The determining means detects vertices of the document image, and determines that the document image is rectangular when there are four detected vertices. Tilt image correction processing device.