WO2004057531A1

WO2004057531A1 - Image synthesizer and program

Info

Publication number: WO2004057531A1
Application number: PCT/JP2002/013337
Authority: WO
Inventors: Shigeaki Nakata; Tatsuya Honmaru
Original assignee: Jicoux Datasystems, Inc.
Priority date: 2002-12-20
Filing date: 2002-12-20
Publication date: 2004-07-08
Also published as: AU2002357631A1; JPWO2004057531A1

Abstract

An image synthesizer for creating a synthesized image from a first image and a second image, in the first image and the second image having an overlapping common image, characterized by comprising a section for comparing the lightness of the common image of the first image, i.e. a first common image, with that of the common image of the second image, i.e. a second common image, a section for regulating the lightness at at least a part of the second image to that of the first image based on the comparison results, and a section for creating a synthesized image including the second image having lightness regulated by the regulating section and the first image.

Description

Image compositing equipment and related programs Technical field

The present invention relates to an image composition device that generates a composite image from a plurality of images.

Light

Background art

Conventionally, image composition for generating one composite image field from a plurality of original images has been performed. For example, a plurality of images obtained by photographing small regions at different positions are combined to generate a combined image of one large region. Conceptually, a composite image is synthesized by projecting each original image onto a plane.

As an example of such image synthesis, there is a case where a plurality of satellite images are synthesized to generate one synthesized image. In this case, a synthesized image of a large area is generated by synthesizing the original images of different latitudes and longitudes.

However, in the conventional image synthesis, if the shooting conditions of the original image are different, the synthesized image obtained by image synthesis may not be preferable. For example, if the shooting time is different, the color of each original image is different, and thus the color of each region of the composite image is different. If the brightness of the original image is different, the brightness of each area of the composite image will be different.

In addition, when a plurality of satellite images are combined to generate a combined image having topographical information of a large area, if a cloud is photographed in each satellite image, the topographical information of the corresponding location is lost.

Therefore, an object of the present invention is to provide an image synthesizing apparatus and a program capable of solving the above-mentioned problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous embodiments of the present invention. Disclosure of the invention

In order to solve the above problems, a first embodiment of the present invention is an image synthesizing apparatus that generates a synthetic image from a first image and a second image, wherein the first image and the second image overlap each other. A comparison unit that has a common image and compares the brightness of the first common image, which is a common image of the first image, with the brightness of the second common image, which is a common image of the second image, and a comparison result of the comparison unit. An adjustment unit that adjusts at least a part of the brightness of the second image to the brightness of the first image based on the second image and a combined image including the second image and the first image whose brightness is adjusted by the adjustment unit An image synthesizing device, comprising: a synthesized image generating unit.

The comparison unit compares the brightness of the first common image with the brightness of the second common image for each predetermined color, and the adjustment unit determines at least a part of the second image based on the comparison result of the comparison unit. The brightness of each of the predetermined colors may be adjusted to the brightness of each of the predetermined colors of the first image. The comparing unit further compares the chromaticity of the first common image with the chromaticity of the second common image, and the adjusting unit determines the chromaticity of at least a part of the second image based on the comparison result of the comparing unit. May be further adjusted to the chromaticity of the first image.

The comparing unit calculates a brightness difference between each pixel of the second common image and each corresponding pixel of the first common image, and calculates a correction coefficient for each brightness of the pixels of the second image based on the brightness difference. A positive coefficient calculation unit, wherein the adjustment unit adjusts the brightness of each pixel of the second image based on the correction coefficient for each brightness. The correction coefficient calculation unit calculates a brightness difference between a pixel in the second common image having a brightness within a predetermined range and a pixel of the first common image corresponding to a pixel of the second common image having a brightness within a predetermined range. May be calculated, and correction coefficients for all the brightnesses of the second image may be calculated based on the brightness difference.

The comparison unit calculates the first standard deviation, which is the standard deviation of the brightness distribution of each pixel in the first common image, and the second standard deviation, which is the standard deviation of the brightness distribution of each pixel in the second common image. And a correction coefficient calculating unit that calculates a first common value having a brightness within a constant multiple of the first standard deviation from the average value of the brightness in the first common image. A pixel in the image and a pixel in the second common image having a brightness within a constant multiple of the second standard deviation from the average value of the brightness in the second common image and corresponding to a pixel in the second common image. The brightness difference may be calculated, and the correction coefficient may be calculated based on the brightness difference.

In the first common image and the second common image, when the high brightness pixels having brightness higher than the predetermined brightness are adjacent to each other by a predetermined number of pixels or more, the comparing unit compares the brightness in an area other than the high brightness pixels. You may.

The correction coefficient calculating unit may extract an area where the brightness difference is smaller than a predetermined value from the calculated brightness difference, and calculate the correction coefficient based on the brightness difference in the extracted area. The image combining device further combines the third image to generate a combined image, the third image has a third common image overlapping the second image, and the second image overlaps the third common image. The comparison unit has a common image, and based on a comparison result between the brightness of the first common image and the brightness of the second common image, and a comparison result between the brightness of the third common image and the brightness of the fourth common image. The brightness of at least a part of the third image is further adjusted to the brightness of the first image, and the composite image generating unit compares the second image, the third image, and the first image whose brightness has been adjusted by the adjusting unit. A composite image may be generated.

The image synthesizing device further includes a selection unit that selects a specified image as a first image from among the plurality of given images and selects another image as a second image, The brightness of at least a part of the first image may be adjusted to the brightness of the specified first image.

Further, the image synthesizing device selects, as the first image, an image having the largest standard deviation of the brightness distribution of each pixel in the common image from the plurality of given images, and selects another image as the second image. The adjustment unit may further include a selection unit that adjusts the brightness of at least a part of the second image to the brightness of the first image having the largest standard deviation.

In the first image and the second image, when the high brightness pixels having brightness higher than the predetermined brightness are adjacent to each other by a predetermined number or more in the first image and the second image, the composite image generation unit replaces the high brightness pixel area with another image. May be used to generate a composite image. According to a second aspect of the present invention, there is provided a program for causing a computer to function as an image synthesizing apparatus that generates a synthetic image from a first image and a second image, wherein the first image and the second image overlap each other. A comparison unit that compares the brightness of the first common image that is the common image of the first image with the brightness of the second common image that is the common image of the second image, An adjustment unit that adjusts the brightness of at least a part of the second image to the brightness of the first image based on the comparison result, and a second image and a first image whose brightness is adjusted by the adjustment unit Provided is a program that functions as a composite image generation unit that generates a composite image.

The above summary of the present invention does not list all of the necessary features of the present invention, and sub-combinations of these features may also be included in the present invention. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing an example of a configuration of an image synthesizing device 100 according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of the operation of the image synthesizing device 100.

FIG. 3 is a diagram illustrating an example of the operation of the comparison unit 10. FIG. 3 (a) shows an example of the brightness distribution of the first common image calculated by the deviation calculation unit 20. FIG. 3 (b) shows the brightness distribution of the second common image calculated by the deviation calculation unit 20. 4 shows an example of a distribution.

FIG. 4 is a diagram illustrating an example of the distribution of the brightness difference between the pixels of the first common image and the corresponding pixels of the second common image.

FIG. 5 is a diagram illustrating an example of the first common image and the second common image.

FIG. 6 is a diagram illustrating an example of a combined image combined by the combined image generation unit 60. FIG. 7 is a flowchart showing an example of the operation of the image synthesizing device 100. FIG. 8 is a diagram showing an example of a configuration of a computer 200 functioning as the image synthesizing device 100. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described through embodiments of the present invention. However, the following embodiments do not limit the invention according to the scope of the patent request, and all combinations of features described in the embodiments are described. Is not necessarily essential to the solution of the invention.

FIG. 1 shows an example of a configuration of an image synthesizing apparatus 100 according to an embodiment of the present invention. The image synthesizing device 100 generates a synthesized image of overlapping common images from a plurality of images. In this example, a case where a composite image is generated from a first image and a second image having overlapping common images will be described.

The image synthesizing device 100 includes a comparing unit 10, a selecting unit 40, an adjusting unit 50, and a synthesized image generating unit 60. The selection unit 40 selects which of the first image and the second image is to be used for adjusting the brightness and chromaticity of another image. For example, the selection unit 40 selects one of the first image and the second image as a reference image based on an instruction signal given in response to an instruction of the user, and adjusts the brightness and color of the other image. Select as the adjustment image to be applied.

In another example, the selection unit 40 may select the reference image and the adjustment image based on the standard deviation of the chromaticity and lightness distribution of the first image and the second image. For example, the selection unit 40 may select an image having the largest standard deviation of the chromaticity distribution as the reference image. That is, by adjusting the lightness and chromaticity of an image having a large range to the lightness and chromaticity of another image, a more preferable image can be synthesized. The selection unit 40 may select a reference image from a plurality of images based on shooting conditions such as shooting time, weather at the time of shooting, and shooting angle. Further, the selecting unit 40 selects an image photographed under substantially the same photographing conditions from the plurality of images given to the image synthesizing device 100, and the image synthesizing device 100 selects the selected image. Images may be combined to generate a combined image. Further, the selection unit 40 may select an image based on the shooting time and shooting location of a given image, and weather information at the time of shooting at the shooting location. In this example, a case will be described in which the selection unit 40 selects the first image as the reference image and selects the second image as the adjustment image.

The comparison unit 10 receives the first image and the second image, and is a common image of the first image. The brightness and chromaticity of the first image or the second image are adjusted by comparing the brightness and chromaticity of the first common image with the brightness and chromaticity of the second common image that is a common image of the second image. Calculate the correction coefficient. Further, it is preferable that the comparing section 10 compares the lightness of the first common image with the lightness of the second common image for each predetermined color.

Further, the comparing unit 10 calculates a distribution and a standard deviation of the brightness and chromaticity of the pixel in each common image, and notifies the selecting unit 40 of the deviation calculating unit 20, and the first image and the second image. A correction coefficient calculating unit that calculates a correction coefficient for adjusting the lightness and chromaticity of one of the images based on the difference between the lightness and chromaticity of the image; The correction coefficient calculation unit 30 calculates a correction coefficient according to the reference image and the selected image selected by the selection unit 40. The details of the operation of the deviation calculator 20 and the correction coefficient calculator 30 will be described later.

The adjustment unit 50 adjusts the brightness of at least a part of the second image to the brightness of the first image based on the comparison result of the comparison unit 10. That is, the adjustment unit 50 adjusts the brightness and chromaticity of the adjustment image selected by the selection unit 40 according to the correction coefficient calculated by the correction coefficient calculation unit 30. Further, it is preferable that the adjusting unit 50 adjusts the brightness of each of the predetermined colors in at least a part of the second image to the brightness of each of the predetermined colors of the first image.

The composite image generation unit 60 generates a composite image including the second image and the first image whose brightness has been adjusted by the adjustment unit 50. Details of the operation of the composite image generation unit 60 will be described later.

According to the image synthesizing device 100 of the present example, it is possible to adjust the difference between the brightness and the chromaticity of a plurality of images, and to generate a synthesized image with the unified brightness and chromaticity. That is, since the first common image and the second common image are images obtained by photographing the same area, the brightness difference, the chromaticity difference, and the like between the corresponding pixels are calculated, and the first common image and the second common image are calculated according to the calculated brightness difference. Lightness and chromaticity can be adjusted by correcting the entire pixel value of the first image or the second image. For this reason, even when images are synthesized from a plurality of satellite images with different brightness, chromaticity, and the like, which are shot under different shooting conditions such as different times, different weather, different shooting angles, etc., the first common image and the first 2 By correcting the image based on the brightness difference of the common image, the brightness and chromaticity are the same as when combining images taken under the same shooting conditions. Can generate a unified composite image.

FIG. 2 is a diagram illustrating an example of the operation of the image composition device 100. In this example, a case will be described in which the image combining device 100 combines the first image, the second image, and the third image. The first image includes a first common image overlapping the second image, and the third image includes a third common image overlapping the second image. Further, the second image includes a second common image overlapping the first image and a fourth common image overlapping the third image.

The selection unit 40 selects the first image as a reference image, and sequentially selects the second image and the third image as adjustment images. The comparing unit 10 performs the third comparison based on the comparison result between the brightness of the first common image and the brightness of the second common image and the comparison result between the brightness of the third common image and the brightness of the fourth common image. Adjust the brightness of at least part of the image to the brightness of the first image.

The correction coefficient calculation unit 30 calculates a correction coefficient based on a difference between brightness and chromaticity in the common image. That is, the correction coefficient calculator 30 calculates the difference between the brightness and chromaticity of the second common image, the brightness and chromaticity of the first common image, the brightness and chromaticity of the third common image, and the fourth common image. The difference between brightness and chromaticity is calculated. The correction coefficient calculating unit 30 calculates a correction coefficient for correcting the second image based on the difference between the brightness and chromaticity of the second common image and the brightness and chromaticity of the first common image, Based on the difference between the brightness and chromaticity of the second common image and the brightness and chromaticity of the first common image, and based on the difference between the brightness and chromaticity of the third common image and the brightness and chromaticity of the fourth common image. Then, a correction coefficient for correcting the third image is calculated. The adjusting unit 50 adjusts the lightness and chromaticity of the entire corresponding second image and the entirety of the third image to the lightness and chromaticity of the first image based on the correction coefficient.

The composite image generation unit 60 composites the second image and the third image whose brightness and chromaticity have been adjusted, and the first image by projecting them on one plane to generate a composite image. Further, the composite image generation section 60 may trim the composite image based on a predetermined trimming frame. At this time, for the area of the common image, a combined image is generated using the common image selected by the selection unit 40. In this example, the first common image is used for the common image area of the first image and the second image, and the second common image is used for the common image area of the second image and the third image. For example, the selection unit 40 is configured to, for each common image, There are few images! / You may select a common image.

FIG. 3 is a diagram illustrating an example of the operation of the comparison unit 10. As described above, since the first common image and the second common image are images of the same region, the brightness difference, chromaticity difference, etc. of the corresponding pixels are calculated, and the first common image and the second common image are calculated according to the calculated brightness difference, etc. By correcting the entire pixel value of the first image or the second image, the brightness and the chromaticity can be adjusted. When an unnecessary image such as a cloud or a shadow is captured in any of the common images, if the brightness difference is calculated including these image elements, the brightness difference cannot be calculated accurately. . The comparison unit 10 in the present example removes these unnecessary image elements and calculates the lightness difference between the first common image and the second common image.

First, the deviation calculator 20 extracts a first common image and a second common image from the given first image and second image. The deviation calculator 20 extracts the first common image and the second common image based on, for example, the additional information added to the first image and the second image. In other words, each common image may be extracted based on the latitude and longitude information of the image capturing area. In addition, the information of the common image is added to the first image and the second image in advance, and the comparing unit 10 may extract each common image based on the information.

The correction coefficient calculating unit 30 calculates a brightness difference between each pixel of the first common image and each corresponding pixel of the second common image, and calculates a correction coefficient for each brightness of the pixels of the second image based on the brightness difference. Is calculated. Here, the correction coefficient calculation unit 30 calculates a δ pixel in the first common image having a lightness within a predetermined range and a second delta pixel having a lightness within a predetermined range and corresponding to a pixel of the first common image. The brightness difference from the pixel of the common image is calculated, and the correction coefficient is calculated based on the brightness difference. The predetermined range is notified from the deviation calculator 20. It is preferable that the correction coefficient calculating section 30 calculates the correction coefficient for each predetermined color. For example, the correction coefficient calculation unit 30 calculates the correction coefficient for each of the red, blue, and green color elements.

The deviation calculating unit 20 calculates the above-described predetermined range based on the brightness distribution of each pixel of the first common image and the second common image. It is preferable that the comparison unit 10 calculates the distribution of the brightness for each predetermined color. For example, the comparison unit 10 has red, blue, + The brightness distribution is calculated for each of the green and green color components.

FIG. ³ (a) shows an example of the brightness distribution of the first common image calculated by the deviation calculating section 20. In Fig. 3 (a), the horizontal axis indicates the intensity of lightness, and the vertical axis indicates the frequency of each lightness. The deviation calculator 20 calculates the average value of the brightness of the first common image and the first standard deviation, which is the standard deviation of the brightness distribution of each pixel in the first common image, based on the calculated brightness distribution. I do. Further, the deviation calculating unit 20 calculates a range of lightness that is a constant multiple of the first standard deviation from the average value of the lightness of the first common image, and calculates a predetermined range of lightness of the first common image (x ₂ to The correction coefficient calculation unit 30 is notified as y ₂ ).

FIG. 3B shows an example of the brightness distribution of the second common image calculated by the deviation calculating section 20. In Fig. 3 (b), the horizontal axis indicates the intensity of lightness, and the vertical axis indicates the frequency of each lightness. The deviation calculator 20 calculates an average value of the brightness of the second common image and a second standard deviation which is a standard deviation of the brightness distribution of each pixel in the second common image based on the calculated brightness distribution. I do. Further, the deviation calculation unit 20 calculates a range of lightness that is a constant multiple of the second standard deviation from the average value of lightness of the second common image, and calculates a predetermined range of lightness of the second common image (x ₂ to The correction coefficient calculation unit 30 is notified as y ₂ ). Here, it is preferable that the deviation calculator '20 calculates a range obtained by multiplying the first standard deviation and the second standard deviation by the same constant. Thereby, in the first common image and the second common image, it is possible to calculate the brightness range including the brightness of the same number of pixels.

According to the deviation calculating unit 20 in this example, the brightness of pixels having high brightness and low brightness compared to the surroundings, such as a cloud or a shadow, can be excluded from a predetermined range. 30 makes it possible to accurately calculate the brightness difference between the first common image and the second common image. Further, the deviation calculator 20 may notify the correction coefficient calculator 30 of a predetermined range of brightness as a predetermined range.

FIG. 4 is a diagram illustrating an example of the distribution of the brightness difference between the pixels of the first common image and the corresponding pixels of the second common image. In FIG. 4, the horizontal axis represents the brightness of the pixels of the second common image, and the vertical axis represents the brightness difference between the pixels of the second common image and the corresponding pixels of the first common image. The correction coefficient calculator 30 calculates the brightness difference for each pixel of the second common image. Is calculated. Next, the correction coefficient calculation unit 30 determines whether the brightness of each of the pixels of the first common image and the pixels of the second common image is within a predetermined range notified from the deviation calculation unit 20. Extract the brightness difference. That is, the correction coefficient calculation unit 3 0, the brightness of the pixels of the second common image is within a predetermined brightness range (x ₂ ~y _2), and the brightness of the pixels of the corresponding first Common image is a predetermined The lightness difference between pixels within the lightness range ( _Xl to _yi ) is extracted.

Next, the correction coefficient calculation unit 30 calculates a correction coefficient for correcting the brightness of the pixels of the second common image based on the extracted brightness difference. For example, the correction coefficient calculation unit 30 calculates a correction coefficient for the entire brightness of the second image by linearly approximating the extracted brightness difference. Further, the correction coefficient calculating section 30 may calculate the correction coefficient by performing a higher-order approximation.

According to the correction coefficient calculating section 30 in this example, it is possible to calculate the brightness difference when an unnecessary image is removed from the same image including unnecessary clouds and shadows, for example. Therefore, the correction coefficient can be calculated with high accuracy.

Further, the correction coefficient calculation unit 30 may extract an area where the brightness difference is smaller than a predetermined value from the calculated brightness difference, and calculate the correction coefficient based on the brightness difference in the area. Since the first common image and the second common image photograph the same area, the brightness difference between the corresponding pixels is mostly within the predetermined range, but any one of the images has clouds or shadows. When is photographed, the brightness difference at the relevant location may increase. By extracting a region where the brightness difference is smaller than a predetermined value, the correction coefficient can be calculated with high accuracy.

In addition, the correction coefficient calculation unit 30 may extract a region with a small variation in distribution from the calculated brightness difference, and calculate the correction coefficient based on the brightness difference in the region.

FIG. 5 shows an example of the first common image and the second common image. In this example, unnecessary clouds 102 are captured in the first common image, and unnecessary shadows 104 are captured in the second common image. As described in FIG. 4, the comparison unit 10 includes the first common image and the second common image. The correction coefficient is calculated based on the brightness difference between the corresponding pixels of the passing image. As described with reference to FIG. 4, in the first common image and the second common image, the cloud 102 and the shadow 100 are calculated. The correction coefficient is calculated excluding the brightness difference of the pixels in the area corresponding to 4. As a result, the correction coefficient can be accurately calculated.

The adjustment unit 50 described with reference to FIG. 1 calculates the brightness of each pixel of the second image based on the correction coefficient for each brightness calculated by the correction coefficient calculation unit 30 described with reference to FIG. Correct for each specified color. Thereby, the brightness and chromaticity of the second image can be adjusted to the brightness and chromaticity of the first image. Further, the comparing unit 10 compares the chromaticity of the first common image with the chromaticity of the second common image in the same manner as the lightness correction coefficient described with reference to FIGS. 50 may adjust at least a part of the chromaticity of the second image to the chromaticity of the first image based on the comparison result of the comparing unit 10.

Also, as described with reference to FIGS. 3 and 4, the comparing unit 10 excludes the cloud and the shadow area based on the distribution of the brightness difference, but in other examples, the cloud and the shadow are excluded by the image processing. May be extracted and excluded. For example, in the first common image and the second common image, when the high-brightness pixels having the brightness higher than the predetermined brightness are adjacent to each other by a predetermined number of pixels or more, the comparison unit 10 may determine the area other than the high-brightness pixels. The lightness at may be compared.

FIG. 6 shows an example of a combined image combined by the combined image generation unit 60. In this example, the composite image generation unit 60 removes unnecessary cloud and shadow images from the composite image. First, a case where an unnecessary image is present in the area of the common image in the composite image will be described. For example, when an unnecessary image is captured in the fourth common image of the second image, the composite image generation unit 60 replaces the second common image with the third image whose brightness and chromaticity have been adjusted. A composite image is generated using the third common image. In other words, in the overlapping common images, it is preferable to combine the images by preferentially using a common image in which an unnecessary image is not captured.

Further, the composite image generation unit 60 extracts an area of the common image where an unnecessary image is captured by image processing, and places the area in a corresponding area of another common image. You may change it. For example, when the high brightness pixels having brightness higher than a predetermined brightness in the common image are adjacent to each other by a predetermined number of pixels or more, the composite image generation unit 60 determines the high brightness pixel as a cloud, and Alternatively, an image may be synthesized using a corresponding area of another common image.

Next, when there is an unnecessary image in a region other than the common image in the composite image, the composite image generation unit 60 extracts the region by image processing and replaces the region with another image. Good. The other images are preferably provided in advance. For example, when a high-brightness pixel having a brightness higher than a predetermined brightness is adjacent to a predetermined number of pixels or more, the composite image generation unit 60 uses another image instead of the high-brightness pixel area. May be synthesized. Further, when there are a plurality of images obtained by photographing the same area, the image synthesizing apparatus 100 may preferentially select an image having a small number of unnecessary image elements to generate a synthesized image.

According to the image synthesizing device 100 in the present example, it is possible to easily generate a synthesized image from which unnecessary images have been removed.

FIG. 7 is a flowchart illustrating an example of the operation of the image composition device 100. First, in the comparison stage, the comparison unit 10 compares the brightness of the common image (S300). In S300, the comparing unit 10 compares the brightness of the common image as described with reference to FIGS. Next, in the adjusting stage, the adjusting unit 50 adjusts the brightness of at least a part of the second image based on the comparison result of the comparing unit 10 (S302). In S302, the adjustment unit 50 adjusts the brightness of the second image as described with reference to FIGS. Next, in the image synthesizing step, the synthesized image generating section 60 generates a synthesized image (S304). In S304, the composite image generation unit 60 generates a composite image as described with reference to FIGS.

FIG. 8 shows an example of a configuration of a computer 200 functioning as the image synthesizing device 100. In this example, the computer 200 stores a program that causes the computer 200 to function as the image synthesizing device 100 described with reference to FIGS. Computer 200 has CPU 700, ROM 702, and RAM 704 , A communication interface 706, a hard disk drive 710, an FD disk drive 712, and a CD-ROM drive 716. The CPU 700 operates based on programs stored in the ROM 702, the RAM 704, the hard disk 710, the FD disk 714, and / or the CD-ROM 718. For example, a program that causes the computer 200 to function as the image synthesizing device 100 includes a computer 200 that has a brightness of a first common image that is a common image of a first image and a brightness of a second common image that is a common image of a second image. A comparison unit 10 that compares the brightness of the second image with the brightness of the first image based on the comparison result of the comparison unit 10; and a brightness adjustment unit 50 that adjusts the brightness of the second image. It is made to function as a composite image generation unit 60 that generates a composite image including the adjusted second image and the first image. For example, the program causes the CPU 700 to function as the image synthesizing device 100. The communication interface 706 communicates with the outside and receives an original image to be combined with an image. A hard disk drive 710 as an example of a storage device stores setting information, a received image, and a program for operating the CPU 700. The ROM 702, the RAM 704, and / or the hard disk drive 7 10 store a program for causing the image composition device 100 to function as the image composition device 100 described with reference to FIGS. In addition, the original image to be combined with the image may be stored in a flexible disk 720, a CD-ROM 722, a hard disk drive 7 10 or the like.

The FD drive 712 reads the program from the flexible disk 714 and provides it to the C-700. The CD-ROM drive 716 reads the program from the CD-ROM 718 and provides it to the CPU 700.

Further, the program may be read directly from the recording medium to the RAM and executed, or may be read into the RAM after being installed in the hard disk drive and executed. Further, the program may be stored on a single recording medium or on a plurality of recording media. The program stored in the recording medium may provide each function in cooperation with the operating system. For example The program may request the operating system to perform some or all of the functions, and provide the functions based on a response from the operating system.

Recording media for storing programs include flexible disks, CD-ROMs, optical recording media such as DVDs and PDs, magneto-optical recording media such as MDs, tape media, magnetic recording media, IC cards and miniature media. A semiconductor memory such as a card can be used. Further, a storage device such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet may be used as a recording medium.

As described above, the present invention has been described using the embodiment, but the technical scope of the present invention is not limited to the scope described in the above embodiment. It is obvious to those skilled in the art that various changes or improvements can be added to the above-described embodiment. It is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention. Industrial applicability

As is apparent from the above description, according to the present invention, when a plurality of images are combined to generate a combined image, the brightness and chromaticity of each image can be adjusted with high accuracy. Also, unnecessary image elements can be removed from the composite image.

Claims

The scope of the claims

1. An image synthesizing device that generates a composite image from a first image and a second image, wherein the first image and the second image have a common image that overlaps,

A comparing unit that compares the brightness of the first common image that is the common image of the first image with the brightness of the second common image that is the common image of the second image;

An adjusting unit that adjusts the brightness of at least a part of the second image to the brightness of the first image based on a comparison result of the comparing unit;

A composite image generation unit that generates a composite image including the second image and the first image whose brightness has been adjusted by the adjustment unit;

An image synthesizing apparatus comprising:

2. The comparing section compares the brightness of the first common image with the brightness of the second common image for each predetermined color,

The adjusting unit adjusts the brightness of each of the predetermined colors in at least a part of the second image to the brightness of each of the predetermined colors of the first image based on a comparison result of the comparison unit. The image synthesizing device according to claim 1, wherein

3. The comparing unit further compares the chromaticity of the first common image with the chromaticity of the second common image,

The method according to claim 1, wherein the adjusting unit further adjusts at least a part of the chromaticity of the second image to the chromaticity of the first image based on a comparison result of the comparing unit. Image synthesis device.

4. The comparison unit is

Correction for calculating a brightness difference between each pixel of the second common image and each corresponding pixel of the first common image, and calculating a correction coefficient for each brightness of the pixels of the second image based on the brightness difference Having a coefficient calculation unit,

2. The apparatus according to claim 1, wherein the adjustment unit adjusts the brightness of each pixel of the second image based on the correction coefficient for each brightness.

5. The correction coefficient calculation unit includes a pixel in the second common image having a brightness within a predetermined range and a pixel corresponding to the pixel in the second common image having a brightness within a predetermined range. 5. The image synthesizing apparatus according to claim 4, wherein a brightness difference from a pixel of the common image is calculated, and the correction coefficients for all brightnesses of the second image are calculated based on the brightness difference.

6. The comparing section

A deviation for calculating a first standard deviation which is a standard deviation of the brightness distribution of each pixel in the first common image, and a second standard deviation which is a standard deviation of the brightness distribution of each pixel in the second common image. Further comprising a calculating unit,

The correction coefficient calculation unit includes: a pixel in the first common image having a brightness within a range of a constant multiple of the first standard deviation from an average value of brightness in the first common image; and a brightness in the second common image. Calculating a brightness difference between a pixel of the first common image and a corresponding pixel of the second common image having a brightness within the constant multiple of the second standard deviation from the average value of the second standard deviation; 6. The image synthesizing apparatus according to claim 5, wherein the correction coefficient is calculated based on a brightness difference.

7. In the first common image and the second common image, the high brightness pixels having brightness higher than a predetermined brightness are adjacent to each other by a predetermined number of pixels or more. 2. The image synthesizing apparatus according to claim 1, wherein the lightness in the areas is compared.

8. The correction coefficient calculation unit may extract an area in which the brightness difference is smaller than a predetermined value from the calculated brightness difference, and calculate the correction coefficient based on the brightness difference in the extracted area. The image synthesizing apparatus according to claim 4, wherein

9. The image composition device further composes a third image to generate the composite image, wherein the third image has a third common image overlapping the second image,

The second image has a fourth common image overlapping the third common image, and the comparing unit is configured to compare a lightness of the first common image with a lightness of the second common image, and (3) Based on the comparison result between the brightness of the common image and the brightness of the fourth common image, And further adjusting the brightness of at least a portion of the third image to the brightness of the first image,

2. The composite image generation section, wherein the composite image generation section generates a composite image including the second image, the third image, and the first image whose brightness has been adjusted by the adjustment section. An image synthesizing device according to claim 1.

10. A selection unit for selecting a designated image as the first image from among the given plurality of images, and selecting another image as the second image,

2. The image synthesizing apparatus according to claim 1, wherein the adjustment unit adjusts at least a part of the brightness of the second image to a specified brightness of the first image.

11. From among the plurality of given images, an image having the largest standard deviation of the brightness distribution of each pixel in the common image is selected as the first image, and another image is selected as the second image. A selecting unit, wherein the adjusting unit adjusts at least a part <lightness of the second image to a lightness of the first image having the largest standard deviation. 2. The image synthesizing device according to claim 1, wherein:

12. The composite image generation unit, when the high brightness pixels having brightness higher than a predetermined brightness in the first image and the second image are adjacent to each other by a predetermined number of pixels or more, the area of the high brightness pixels The image synthesizing apparatus according to claim 1, wherein the synthesized image is generated using another image instead of the image.

13. A program that causes a computer to function as an image synthesis device that generates a synthesized image from the first image and the second image,

The first image and the second image have an overlapping common image,

The program causes the computer to:

Including the second image and the first image whose brightness has been adjusted by the adjusting unit A program for causing a computer to function as a composite image generation unit that generates a composite image