JP2009183342A - Image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image divider which does not require binarization of a captured image, is not affected by scars and dirt of a film, can deal with a mixture of small images difference in size, can deal with shapes of the small images other than rectangle, and can deal with an arrangement of small images even when the small images are not in a grid shape. <P>SOLUTION: A frequency distribution of image brightness constituting captured images and an average value of frequency of the brightness are obtained. The brightness having frequency exceeding the average value is detected as a background brightness to be brightness of a background part. The frequency distribution of the brightness other than the background brightness is obtained, and an arrangement of the small images in an image region of images captured on the basis of the frequency distribution is obtained. Thus, it is possible to divide small images precisely without being affected by scars or dirt of the film even when small images different in size mix, shapes of the small images are not rectangle, or the arrangement of the small images is not in the grid shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is an apparatus for dividing a small image included in this image from a captured image, and in particular, a plurality of small images included inside a medical image captured from one film. It is related with the apparatus for dividing | segmenting into.

  When electronically storing a plurality of small images printed on one film, it may be necessary to divide and store the small images one by one. For example, in the medical field, medical images are usually printed as a plurality of small images on a single film. When medical images are stored electronically, they can be stored separately for each small image. Required.

  Conventionally, when a plurality of medical images printed on a single film are individually divided and electronically stored, the plurality of images on the screen are viewed, and an instruction is manually given to the apparatus to perform the divided electronic storage. It was.

As an apparatus that can automatically divide a plurality of small images contained in one film, an “image processing apparatus and method” (Patent Document 1) has been proposed.
The image processing apparatus described in Patent Document 1 is characterized in that the arrangement of small images is detected based on the dispersion of pixel values constituting the captured image. As a result, a plurality of small images can be cut out accurately, easily and in a short time.
JP 2000-342539 A

  However, in the conventional image dividing apparatus described in Patent Document 1, it is necessary to binarize the captured image in order to suppress the influence of film scratches and dirt. For this reason, in an image with many intermediate gradations, there is a possibility that the binarized image varies greatly depending on the setting of the threshold value for binarization, and the division is not accurately performed after all.

In addition, the conventional image segmentation device described in Patent Document 1 cannot cope with a case where small images having different sizes are included, and cuts out a small image based on the size of the largest small image. There was a problem.
Furthermore, the conventional image segmentation device described in Patent Document 1 has a problem in that it cannot be handled unless small images are properly arranged in a grid pattern.
Furthermore, in the conventional dividing apparatus described in Patent Document 1, there is a possibility that a small image cannot be accurately divided in a shape other than a rectangle.

  The present invention has been made in view of such circumstances, does not require binarization, is not affected by film scratches and dirt, and can cope with a mixture of small images of different sizes. It is an object of the present invention to provide an image dividing apparatus that can cope with shapes other than rectangles and can accommodate small images arranged in a grid pattern.

The problems of the present invention can be solved by the following inventions.
In other words, the image dividing apparatus of the present invention is an image processing apparatus that includes an image capturing unit that captures an image and an image processing unit that performs processing of the captured image, and the image processing unit captures the captured image. A background detecting unit for detecting a background portion that is a non-image portion in an image area; and an image dividing unit for dividing each of a plurality of small images included in the captured image. The brightness frequency distribution of the pixels constituting the captured image and the average value of the brightness frequency are obtained, and the brightness having a frequency exceeding the average value is detected as the background brightness that is the brightness of the background portion. The image dividing means obtains a frequency distribution of brightness other than the background brightness among the brightness of pixels constituting the captured image, and based on the frequency distribution, It is mainly characterized in that to determine the placement of the small image.

  Thus, since the background brightness is detected based on the frequency distribution of the brightness of the pixels and the arrangement of the small images is detected, binarization is not necessary, and it is difficult to be affected by film scratches and dirt.

  In the image dividing apparatus according to the present invention, the image dividing means may include a plurality of captured images as straight lines parallel to the Y axis, where the captured image has a vertical direction as the Y axis and a horizontal direction as the X axis. The strip-shaped area is divided into a plurality of strip-shaped areas, a frequency distribution of brightness other than the background brightness is obtained for each of the strip-shaped areas, and the strip-shaped area having a frequency greater than a preset value is selected from the strip-shaped areas. And detecting the frequency distribution of lightness other than the background lightness for each of the strip-like areas, and detecting the frequency distribution of the lightness other than the background brightness for each of the strip-like areas. The strip-shaped region having a frequency greater than a preset value is detected as a second strip-shaped region, and a region where the first strip-shaped region and the second strip-shaped region intersect is defined as a divided image core unit. Detect and split the image core It is mainly characterized in that to determine the placement of the small image on the basis of the arrangement.

Furthermore, in the image dividing device according to the present invention, the image dividing means is a three-dimensional image in which the vertical axis and horizontal axis of the captured image are the y-axis and x-axis, respectively, and the z-axis is a frequency of lightness other than the background lightness. A histogram is obtained, and an area on the xy plane having a frequency greater than a preset value in the three-dimensional histogram is detected as a divided image core part, and the small image of the small image is determined based on the arrangement of the divided image core part. The main feature is to seek placement.
As a result, the background brightness portion is not erroneously recognized as the divided image core portion. Further, since the arrangement of the small images is detected based on the three-dimensional histogram, it can be accurately divided even if the small images are not arranged in a grid pattern.

  Furthermore, the image dividing apparatus according to the present invention is configured such that each vertex of a rectangle constituting the divided image core portion is arranged in the outer direction of the rectangle when the vertical direction of the captured image is the Y axis and the horizontal direction is the X axis. A point moved in the X-axis direction until the lightness of the image reaches the background lightness is detected as an X-moving point, and each vertex of the rectangle is located outside the rectangle and in the Y-axis direction. Is detected as a Y movement point, a rectangle including all of the X movement point and the Y movement point and having the smallest area is detected as an enlargement rectangle, The main feature is to obtain the arrangement of the small image based on the arrangement.

  As a result, the size of the divided image core portion is adjusted to the size of the corresponding small image one by one, so that it is possible to accurately divide even if small images having different sizes are mixed. Further, even if the small images are not arranged in a grid pattern, the size of the divided image core portion is adjusted to the size of the corresponding small image one by one, so that it can be divided accurately.

In addition, when a plurality of the enlarged rectangles overlap each other, the image dividing device of the present invention detects a rectangle that includes all of the overlapped enlarged rectangles and has the smallest area as a combined rectangle, and arranges the combined rectangles. The main feature is to obtain the arrangement of the small images based on the above.
Thereby, even if small images having different sizes are mixed, it can be divided more accurately.

Further, at least one check point is provided for each side constituting the enlarged rectangle or the combined rectangle, and the side including the check point is moved outward until the lightness of the check point reaches the background lightness. The main feature is that a correction rectangle obtained by enlarging the rectangle or the combined rectangle is detected, and the arrangement of the small images is obtained based on the correction rectangle.
As a result, even if the small image has a shape other than a rectangle, it can be accurately divided.

  As described above, according to the image segmentation device of the present invention, the background brightness is detected based on the frequency distribution of pixel brightness, and the arrangement of small images is detected. It is characterized by being less susceptible to scratches and dirt.

  Further, since the detection is performed based on the three-dimensional histogram, the background brightness portion is not erroneously recognized as the divided image core portion, and the image can be accurately divided even if a small image is not arranged in a grid pattern.

  Furthermore, since the size of the divided image core is adjusted to the size of the corresponding small image one by one, even if small images of different sizes are mixed, it can be accurately divided, and the small image is formed in a grid pattern. Even if it is not arranged, it can be accurately divided.

  Furthermore, since the size of the small image is finely adjusted one by one, even if the small image has a shape other than a rectangle, it can be accurately divided.

  The best mode for carrying out an image processing apparatus of the present invention will be described below in detail with reference to the accompanying drawings.

<Configuration>
A configuration of an image processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an image processing apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the image processing apparatus of the present invention includes an image capturing unit 1 and an image processing unit 2. The image capturing unit 1 captures an image from a film. For example, the image capturing unit 1 has functions such as a film scanner and an image scanner, and can directly capture an image from a film.
Further, the image capturing unit 1 can capture an image not only from a film but also from an external storage device such as a hard disk.

  The image processing unit 2 includes a background detection unit 3 and an image division unit 4. The background detection means 3 detects a background portion in the image. Here, the background portion refers to a portion that is not an image in the image region, that is, a frame portion. For example, in the case where a plurality of small images are arranged in the image area, it means a portion of a frame that partitions each small image.

  The image dividing unit 4 generates a dividing line that divides a plurality of small images in the image using the background detected by the background detecting unit 3. Further, the image dividing unit 4 can detect the arrangement of a plurality of small images in the image using the background detected by the background detecting unit 3 and cut out these small images individually. Each can be saved as a separate file.

<Operation>
Next, the operation of the image processing apparatus according to the embodiment of the present invention will be described with reference to FIGS. FIG. 2 is an operation flowchart of the image processing apparatus of the present invention.

  As shown in FIG. 2, the image capturing unit 1 captures an image from the film (S21). The background detection means 3 detects the brightness of the background portion in the image captured by the image capture unit 1 (S22). Hereinafter, the lightness of the background portion is referred to as background lightness. Here, background lightness detection (S22) will be further described with reference to FIGS. FIG. 3 is a flowchart of background lightness detection. FIG. 4 is a diagram showing the frequency distribution of the brightness of the pixels constituting the image. FIG. 5 is also a diagram showing the frequency distribution of the brightness of the pixels constituting the image captured by the image capturing unit 1.

  As shown in FIG. 3, the background detection unit 3 obtains the frequency distribution of the brightness of the pixels constituting the image captured by the image capturing unit 1. FIG. 4 shows this frequency distribution. As shown in FIG. 4, for example, when the background lightness is dark, a peak is present in a dark portion that is the background lightness, and there are many cases in which the frequency distribution has no particular peak in other cases.

  This is because the background lightness is high because the background lightness is the same, whereas the image portion often has a wide variety of lightnesses, so the frequency is not high compared to the background lightness. is there.

  Next, the background detection means 3 calculates the average value of the frequencies (S32). A line denoted by reference numeral 41 is a line indicating an average frequency. The background detection means 3 sets the lightness having a frequency exceeding the average value of the frequencies as the background lightness. At this time, the background lightness often has a certain range. Reference numeral 42 indicates a range of background brightness.

Here, the case where the background lightness is dark has been described. However, the same applies to the case where the background lightness is bright or arbitrary lightness, and the description thereof will be omitted.
As a result of inventor's diligent research, it was found that the background lightness can be detected very accurately in many cases by obtaining the lightness having a frequency exceeding the frequency average value of the image lightness. Thus, by obtaining the lightness having a frequency exceeding the lightness frequency average value, it is possible to detect the background lightness easily and accurately.

  Next, returning to FIG. 2, the background detection means 3 determines whether or not the background exists, that is, whether or not the background lightness has been detected (S23). If it cannot be detected, an error message to that effect is displayed on the screen and the process is terminated.

  The case where the background lightness cannot be detected includes, for example, the case where the image area has no frame portion and is entirely an image. In this case, the lightness frequency distribution has a frequency that exceeds the lightness frequency average value. The brightness will be scattered in various ranges from dark to bright without being fixed in one place. Thus, in the present invention, it is possible to detect the presence or absence of the background.

  The background detection means 3 determines whether or not the background lightness range is larger than a preset setting range (S24). If it is larger than the set range, S26 is executed. If not, the next step is executed. Execute S25

If the background lightness range is larger than the set range, the background detection means 3 performs a background detection retry (S26). Background detection retry (S26) will be described with reference to FIG. When the background lightness range indicated by reference numeral 52, which is a lightness having a higher frequency than the frequency average value indicated by reference numeral 51, is larger than the set value, the background detection means 3 is one of the following preset methods: The background lightness is determined by the method.
(1) The range of the darkest side among the peaks having the frequency peak is set as the background brightness.
(2) The range of the mountain on the brightest side among the peaks having the frequency peak is set as the background brightness.
(3) The range of the mountain at the center of the peaks having the frequency peak is set as the background brightness.
(4) The range of the mountain having the highest peak among the peaks having the frequency peak is defined as the brightness range.
Which of the above methods can detect the background brightness most appropriately depends on the type of image, and can be arbitrarily set depending on the type of image.

  Returning to FIG. 2, the background detection means 3 determines whether or not the background lightness has been determined (S27). If the background lightness cannot be determined by the above method, an error has occurred. If the background brightness is determined after displaying the effect on the screen or the like, S25 is executed.

  If it is determined in S24 that the background brightness range is not larger than the preset range, the image dividing unit 4 divides each of the divided images for dividing the plurality of small images in the image area into small images. The divided image core portion, which is the core portion, is detected.

  The detection of the divided image core part will be described with reference to FIG. FIG. 6 is an explanatory diagram of detection of the divided image core unit. In FIG. 6, the horizontal axis of the image area is described as the X axis, and the vertical axis is described as the Y axis. As shown in FIG. 6, the image dividing means 4 finely divides the image area by a straight line perpendicular to the X axis, that is, a straight line parallel to the Y axis, and the frequency of lightness other than the background lightness for each of the divided strip-like areas. Ask for. A histogram representing the position of the X axis on the horizontal axis and the frequency of lightness other than the background lightness on the vertical axis is denoted by reference numeral 61.

  Similarly, the image dividing means 4 finely divides the image area by a straight line perpendicular to the Y axis, that is, a straight line parallel to the X axis, and obtains the frequency of lightness other than the background lightness for each of the divided strip-like areas. The histogram thus obtained is indicated by reference numeral 62.

  The image dividing means 4 obtains a strip-like area having a frequency larger than a preset value in each obtained histogram, and detects the intersecting portion of the obtained strip-like areas as the divided image core unit 63. The image dividing means 4 examines the lightness of the pixels constituting each obtained divided image core unit 63 itself, and those in which the lightness of all the pixels is the background lightness can be excluded as not being the divided image core unit. This is because the background portion may also enter the intersecting region in the method in which the region where the strip-shaped regions whose longitudinal directions intersect the X-axis direction and the Y-axis direction are the divided image core part.

  Here, the dividing means 4 can obtain the divided image core part by obtaining a three-dimensional histogram other than the above method. Specifically, the X-axis and Y-axis of the three-dimensional histogram are the X-axis and Y-axis of the image area, respectively, the Z-axis is the frequency of brightness other than the background brightness, and X− has a frequency greater than a preset frequency. A region on the Y plane can be used as a divided image core portion. In this method, the background portion is not erroneously recognized as the divided image core portion.

  Returning to FIG. 2, next, the image dividing unit 4 enlarges the obtained divided image core part, and detects a rectangle in which the divided image core part is enlarged to the same size as the small image existing in the image area. I do. A specific example will be described with reference to FIG. FIG. 7 is an enlarged explanatory diagram of the divided image core part. In FIG. 7, the horizontal axis is referred to as the X axis, and the vertical axis is referred to as the Y axis.

  As shown in FIG. 7, the image dividing means 4 is a rectangular ABCD (hereinafter referred to as the ABCD) constituting the divided image core unit 63 for the four vertices (A, B, C, D) of the divided image core unit 63 in the image region. It is extended in the outward direction of the rectangle ABCD) until the background brightness is reached. The vertex A will be described in more detail as an example. The vertex A is extended in the Y axis direction outside the rectangle ABCD until the lightness becomes the background lightness. Let Ay be the point where the background brightness is reached. Similarly, the vertex A is extended in the Y axis direction outside the rectangle ABCD until the lightness becomes the background lightness. Let Ax be the point where the background brightness is reached. The same operation is performed for the remaining vertices B, C, and D.

  An enlarged rectangle 71 that is a rectangle that includes all of Ax, Ay, Bx, By, Cx, Cy, Dx, and Dy and has the smallest area is detected.

  Here, when all of the vertices A, B, C, and D have the background lightness, conversely, until the lightness disappears from the background lightness in the X-axis and Y-axis directions at the respective vertexes and inside the rectangle ABCD. Each vertex can be stretched. At this time, if no brightness other than the background brightness can be detected even if the image is extended until it extends beyond the rectangle ABCD, the point is extinguished. Thereby, when the divided image core part 63 is a background part, all the vertices disappear and the divided image core part 63 disappears. That is, even if the background portion is erroneously recognized as the divided image core unit 63, the divided image core unit 63 of the background portion can be erased by this operation.

  If each divided image core part 63 is enlarged in this way, there may be a case where the enlarged rectangles 71 meet considerably. The operation at this time will be described with reference to FIG. FIG. 8 is an explanatory diagram of an enlarged rectangular combination. As shown in FIG. 8, when the enlarged rectangles 71 overlap with each other, the image dividing unit 4 detects a combined rectangle 81 that includes all the overlapped rectangles and has the smallest area.

  The image dividing unit 4 corrects the finally obtained enlarged rectangle 71 and combined rectangle 81 (hereinafter referred to as the final rectangle). This correction will be described with reference to FIG. FIG. 9 is an explanatory diagram of correction of the final rectangle. As shown in FIG. 9, when the small image in the image area is not rectangular, for example, when it is a circular small image as indicated by reference numeral 91, the small image 91 is not fully contained in the final rectangle. There can be.

Therefore, the image dividing unit 4 detects the lightness of each of the midpoints i, b, c, and d of the four sides of the final rectangle for all the final rectangles, and if it is not the background lightness, the midpoint becomes the background lightness. The final rectangle can be corrected by moving the side to the outside of the final rectangle. Here, not only the midpoints of the four sides, but also checkpoints that are a plurality of checkpoints are provided on each side, and each side is moved outside the final rectangle so that the background brightness is at all checkpoints. You can also. In addition, the entire four sides are checked instead of the points, and if the side includes a point that is not background lightness, the side can be moved outside the final rectangle.
As a result, even when the small image is not a rectangle, the entire small image can be reliably contained in the final rectangle by correcting the final rectangle.

  Returning to FIG. 2, the image dividing means 4 counts the number of the enlarged rectangle 71 and the combined rectangle 81 finally obtained in this way, and determines whether or not the number is one (S29). ). If it is determined that the number is one, the fact is displayed on a screen or the like and the process is terminated. Thereby, the number of the enlarged rectangle 71 and the combined rectangle 81 finally obtained is the number of small images in the captured image, so that the number of small images included in the captured image can be accurately detected. .

Returning to FIG. 2, the image dividing means 4 generates a dividing line for dividing each small image in the image region. The dividing line can be provided at the opposite side of the adjacent final rectangle and in the middle of the side. At this time, the image dividing unit 4 inspects the generated dividing line, and if the dividing line intersects with the final rectangle, deletes the portion where the dividing line intersects.
Thereby, even if the small images are not arranged in a grid pattern, it is possible to generate a dividing line for accurately dividing the small image.
As described above, the image processing apparatus of the present invention detects the background lightness and obtains the frequency distribution of the lightness other than the background lightness, thereby accurately detecting the arrangement of the small images, dividing the small images, It is possible to easily and accurately generate a dividing line for dividing.

  Further, since background brightness detection and small image arrangement detection are performed based on the frequency distribution, it is difficult to be affected by scratches and dirt, and accurate and stable division of small images is possible.

  The image processing apparatus according to the present invention has been described with reference to specific embodiments, but the present invention is not limited to these. A person skilled in the art can make various changes and improvements to the configuration and functions of the image processing apparatus according to the above-described embodiment without departing from the gist of the present invention.

  The image dividing apparatus of the present invention is realized by an OS, an application, an image sensor, and the like built on hardware resources including a computer CPU, memory, auxiliary storage device, display, and the like. Since the process of recognizing and dividing the contained small image is specifically realized by using the above hardware resources, it corresponds to the technical idea using the law of nature, Various fields that require image data processing, such as electronic storage of medical images, processing of digital camera images, and processing of image data read by an image scanner, which are fields in which small images need to be divided from images that contain images Can be used in various fields.

1 is a schematic configuration diagram of an image processing apparatus according to an embodiment of the present invention. It is an operation | movement flowchart of the image processing apparatus of this invention. It is a flowchart of background lightness detection. It is the figure which showed the frequency distribution of the brightness of the pixel which comprises an image. It is the figure which showed the frequency distribution of the brightness of the pixel which comprises an image. It is detection explanatory drawing of a division | segmentation image core part. It is a divisional image core part expansion explanatory drawing. It is coupling | bonding explanatory drawing of an expansion rectangle. It is correction | amendment explanatory drawing of the last rectangle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image capture part 2 Image processing part 3 Background detection means 4 Image division means 41 Frequency average value 42 Background brightness 51 Frequency average value 52 Background brightness 61 Histogram showing the frequency of brightness other than background brightness 62 Brightness other than background brightness Histogram 63 representing frequency Divided image core portion 71 Enlarged rectangle 81 Combined rectangle 91 Circular small image

Claims (12)

An image processing apparatus comprising: an image capturing unit that captures an image; and an image processing unit that performs processing of the captured image,
The image processing unit
A background detection means for detecting a background portion that is a non-image portion in the area of the captured image;
Image dividing means for respectively dividing a plurality of small images included in the captured image;
With
The background detection means includes
Find the brightness frequency distribution of the pixels constituting the captured image and the average value of the brightness frequency, and detect the brightness having a frequency exceeding the average value as the background brightness, which is the brightness of the background part,
The image dividing means includes
Obtaining the frequency distribution of brightness other than the background brightness among the brightness of the pixels constituting the captured image, and determining the arrangement of the small images in the image area of the captured image based on the frequency distribution;
An image processing apparatus. The image dividing means includes
When the vertical direction of the captured image is the Y axis and the horizontal direction is the X axis,
The captured image is divided into a plurality of strip-shaped areas by straight lines parallel to the Y-axis, a frequency distribution of brightness other than the background brightness is obtained for each of the strip-shaped areas, and from a preset value of the strip-shaped areas Detecting the strip-shaped region having a large frequency as a first strip-shaped region;
The captured image is divided into a plurality of strip-shaped areas by straight lines parallel to the X axis, and a frequency distribution of brightness other than the background brightness is obtained for each of the strip-shaped areas. From a preset value of the strip-shaped areas Detecting the strip-shaped region having a large frequency as a second strip-shaped region;
Detecting an area where the first strip-shaped area and the second strip-shaped area intersect as a divided image core part, and determining the arrangement of the small image based on the arrangement of the divided image core part;
The image processing apparatus according to claim 1. The image dividing means includes
Obtaining a three-dimensional histogram in which the vertical and horizontal axes of the captured image are the y-axis and the x-axis, respectively, and the z-axis is the frequency of lightness other than the background lightness,
In the three-dimensional histogram, an area on the xy plane having a frequency greater than a preset value is detected as a divided image core part, and the arrangement of the small image is obtained based on the arrangement of the divided image core part. ,
The image processing apparatus according to claim 1. When the vertical direction of the captured image is the Y axis and the horizontal direction is the X axis,
Detecting, as an X movement point, each vertex of the rectangle constituting the divided image core portion that is moved outside the rectangle in the X-axis direction until the brightness of the image reaches the background brightness,
Detecting each vertex of the rectangle as a Y movement point by moving the vertex of the image in the Y axis direction until the brightness of the image reaches the background brightness,
A rectangle that includes all of the X movement point and the Y movement point and has the smallest area is detected as an enlarged rectangle, and the arrangement of the small image is obtained based on the arrangement of the enlarged rectangle;
The image processing apparatus according to claim 2, wherein the image processing apparatus is an image processing apparatus. When a plurality of the enlarged rectangles overlap, a rectangle including all of the overlapping enlarged rectangles and having the smallest area is detected as a combined rectangle, and the arrangement of the small images is obtained based on the arrangement of the combined rectangles. ,
The image processing apparatus according to claim 4. At least one check point is provided for each side constituting the enlarged rectangle or the combined rectangle, and the side including the check point is moved outward until the lightness of the check point reaches the background lightness. Detecting a correction rectangle obtained by enlarging the combined rectangle, and obtaining an arrangement of the small image based on the correction rectangle;
The image processing apparatus according to claim 4, wherein: An image processing program for causing a computer to execute an image capturing step for capturing an image and an image processing step for processing the captured image,
The image processing step includes
A background detection step of detecting a background portion that is a non-image portion in the captured image region;
An image dividing step of dividing each of the plurality of small images included in the captured image;
With
The background detection step includes
A step of obtaining a lightness frequency distribution of pixels constituting the captured image and an average value of the lightness frequencies, and detecting a lightness having a frequency exceeding the average value as a background lightness that is a lightness of a background portion. And comprising steps
The image dividing step includes
Of the brightness of the pixels constituting the captured image, obtaining a frequency distribution of brightness other than background brightness, and determining the placement of the small image in the image area of the captured image based on the frequency distribution; ,
An image processing program comprising: The image dividing step includes
When the vertical direction of the captured image is the Y axis and the horizontal direction is the X axis,
A step of dividing the captured image into a plurality of strip-shaped regions by straight lines parallel to the Y axis, a step of obtaining a frequency distribution of brightness other than the background brightness for each of the strip-shaped regions, and a preset of the strip-shaped regions Detecting the strip-shaped region having a frequency greater than the value as a first strip-shaped region;
A step of dividing the captured image into a plurality of strip-shaped regions by straight lines parallel to the X axis, a step of obtaining a frequency distribution of lightness other than the background lightness for each of the strip-shaped regions, and a preset of the strip-shaped regions Detecting the strip-shaped region having a frequency greater than the value as a second strip-shaped region;
Detecting an area where the first strip-shaped area and the second strip-shaped area intersect as a divided image core part, and determining the arrangement of the small image based on the arrangement of the divided image core part;
The image processing program according to claim 7, further comprising: The image dividing step includes
Obtaining a three-dimensional histogram in which the vertical and horizontal axes of the captured image are the y-axis and the x-axis, respectively, and the z-axis is a lightness frequency other than the background lightness;
In the three-dimensional histogram, detecting a region on the xy plane having a frequency greater than a preset value as a divided image core portion, and arranging the small images based on the arrangement of the divided image core portions. Seeking steps,
The image processing program according to claim 7, further comprising: When the vertical direction of the captured image is the Y axis and the horizontal direction is the X axis,
Detecting, as an X movement point, a point in which each vertex of the rectangle constituting the divided image core portion is moved in the X-axis direction until the brightness of the image reaches the background brightness in the outer direction of the rectangle;
Detecting a point where each vertex of the rectangle is moved in the Y-axis direction in the outer direction of the rectangle until the brightness of the image reaches the background brightness, as a Y movement point;
Detecting a rectangle that includes all of the X movement point and the Y movement point and has the smallest area as an enlarged rectangle, and obtaining an arrangement of the small image based on the arrangement of the enlarged rectangle;
The image processing program according to claim 8, further comprising: When a plurality of the enlarged rectangles are overlapped, detecting a rectangle including all of the overlapped enlarged rectangles and having the smallest area as a combined rectangle, and arranging the small image based on the arrangement of the combined rectangles Seeking steps,
The image processing program according to claim 10, further comprising: Providing at least one check point for each side constituting the enlarged rectangle or the combined rectangle, and moving the side including the check point outward until the lightness of the check point becomes background lightness, Detecting a rectangle or a correction rectangle obtained by enlarging the combined rectangle; and determining an arrangement of the small image based on the correction rectangle;
The image processing program according to claim 10, further comprising:

Images