JP3584198B2 - Image processing method and apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image processing method and apparatus for generating a mosaic image by combining a plurality of material images like a mosaic.
[0002]
[Prior art]
Conventionally, mosaic has been widely known as "a combination of small pieces of stone, glass, marble, etc. of various colors, fitted into floors, walls, etc., and designed, or the technique" (Sanseido Modern Japanese Dictionary). . Using this technique, a number of photographic images can be combined to form a design or a single photographic image.
[0003]
[Problems to be solved by the invention]
When creating such a mosaic image, the original image is divided into a plurality of areas (tile areas), and a material image (tile image) constituting the mosaic image is incorporated into each of these areas (tile areas). Create an image. In this case, a material image close to the color of the divided tile area of the original image is selected from a plurality of material images and mechanically pasted.
[0004]
At this time, if there is no material image sufficiently similar to the color of each tile area, there is a problem that the quality of the generated mosaic image is not good.
[0005]
The present invention has been made in view of the above conventional example, and focuses on a luminance component, not a color difference component of an original image, and performs processing of selecting and pasting a corresponding material image to generate a monochrome mosaic image. It is an object to provide a processing device and a method thereof.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an image processing apparatus according to the present invention has the following configuration. That is,
An image processing apparatus that creates an image imitating an original image by combining a plurality of material images selected from a plurality of material images,
Dividing means for dividing the original image into a plurality of regions;
Calculating means for calculating an average density and an average luminance of each color of each of the plurality of regions divided by the dividing means;
Based on the average density of each color of each of the material image and the average density of each color of calculating said plurality of regions by said calculating means, an image selection means for selecting a material images corresponding to each of the plurality of regions ,
Image pasting means for generating a color image by pasting the material images selected by the image selecting means to the corresponding areas,
Inspection means for inspecting the quality of the color image bonded by the image bonding means,
Means for determining whether or not to convert the color image to monochrome, according to an inspection result by the inspection means,
At the time of the monochrome conversion, the image selection unit is configured to calculate the material image corresponding to each of the plurality of regions based on the average luminance of the plurality of regions and the average luminance of the material image calculated by the calculation unit. Is selected, the selected material image is converted to a monochrome image, and the monochrome image is generated by pasting the selected material image on a corresponding area .
In order to achieve the above object, an image processing apparatus according to the present invention has the following configuration. That is,
An image processing apparatus that creates an image imitating an original image by combining a plurality of material images selected from a plurality of material images,
Dividing means for dividing the original image into a plurality of regions;
Calculation means for calculating the respective average density及 beauty average luminance of each color of the plurality of regions divided by the dividing means,
An image selection unit that selects a material image corresponding to each of the plurality of regions based on an average density of each color of each of the plurality of regions and an average density of each color of the material image calculated by the calculation unit; ,
Image pasting means for generating a color image by pasting the material images selected by the image selecting means to the corresponding areas,
Inspection means for inspecting the quality of the color image bonded by the image bonding means,
Means for determining whether or not to convert the color image to monochrome, according to an inspection result by the inspection means,
At the time of the monochrome conversion, the image selection unit is configured to calculate the material image corresponding to each of the plurality of regions based on the average luminance of the plurality of regions and the average luminance of the material image calculated by the calculation unit. Is selected, and the selected material images are pasted to corresponding areas to generate color images, and the entirety of the generated color images is converted to monochrome.
[0007]
In order to achieve the above object, the image processing method of the present invention includes the following steps. That is,
An image processing method for creating an image imitating an original image by combining a plurality of material images selected from a plurality of material images,
A dividing step of dividing the original image into a plurality of regions;
A calculating step of calculating an average density and an average luminance of each color of each of the plurality of regions divided in the dividing step;
Based on the average density of each color of each of the material image and the average density of each color of the plurality of areas calculated in the calculating step, an image selection step of selecting the material images corresponding to each of the plurality of regions ,
Image pasting step of pasting the material image selected in the image selecting step to the corresponding area to generate a color image,
An inspection step of inspecting the quality of the color image bonded in the image bonding step,
A step of determining whether or not to convert the color image to monochrome according to the inspection result of the inspection step,
At the time of the monochrome conversion, in the image selecting step, based on the average luminance of each of the plurality of areas and the average luminance of the material image calculated in the calculating step, the material image corresponding to each of the plurality of areas. Is selected, the selected material image is converted to a monochrome image, and the monochrome image is generated by pasting the selected material image on a corresponding area .
In order to achieve the above object, the image processing method of the present invention includes the following steps. That is,
An image processing method for creating an image imitating an original image by combining a plurality of material images selected from a plurality of material images,
A dividing step of dividing the original image into a plurality of regions;
A calculating step of calculating an average density and an average luminance of each color of each of the plurality of regions divided in the dividing step;
An image selection step of selecting a material image corresponding to each of the plurality of regions based on the average density of each color of each of the plurality of regions and the average density of each color of the material image calculated in the calculation step; ,
Image pasting step of pasting the material image selected in the image selecting step to the corresponding area to generate a color image,
An inspection step of inspecting the quality of the color image bonded in the image bonding step,
A step of determining whether or not to convert the color image to monochrome according to the inspection result of the inspection step,
At the time of the monochrome conversion, in the image selecting step, based on the average luminance of each of the plurality of areas and the average luminance of the material image calculated in the calculating step, the material image corresponding to each of the plurality of areas. Is selected, and the selected material images are pasted to corresponding areas to generate color images, and the entirety of the generated color images is converted to monochrome.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0009]
FIG. 1 is a block diagram illustrating a schematic configuration of an image processing apparatus according to an embodiment of the present invention.
[0010]
In FIG. 1, reference numeral 101 denotes a CPU, which controls the operation of the entire apparatus according to a program stored in a RAM 105. A keyboard 102 is used by a user together with a mouse or the like serving as a pointing device 102a, and is used to input various data to the apparatus. A display unit 103 includes, for example, a CRT or a liquid crystal. A ROM 104 and a RAM 105 store programs used in this apparatus and various data. A hard disk device 106 stores programs and data installed from a floppy disk 107 or a CD-ROM drive (not shown). The hard disk device 106 and the floppy disk device 107 also constitute an external storage device used for the file system of the image processing device. Reference numeral 108 denotes a printer, such as a color inkjet printer or an electrophotographic printer.
[0011]
The hard disk device 106 stores a plurality (P) of tile images (material images) serving as constituent elements of a mosaic image. According to a program described later, M × N images selected from these images are stored in the hard disk device 106. As shown in FIG. 2, a mosaic image is created by arranging and combining M images in the horizontal direction and N images in the vertical direction. The mosaic image thus created is stored as an image file on the hard disk device 106, or displayed on the CRT 103, or output to the printer 108 and printed.
[0012]
Note that the hard disk device 106 may store the average brightness of each of the material images together with the material images.
[0013]
FIG. 3 is a diagram illustrating a relationship between a plurality of types of images used in the mosaic method according to the present embodiment.
[0014]
In FIG. 3, an image 201 is an original design or image when an image is formed using a mosaic method. The image 202 is an image formed by using a plurality of small images (tile images) by a mosaic method. The image 201 is configured by dividing the image 201 into a plurality of tile areas, and selecting and pasting a material image suitable for each tile area. ing. The material image 203 is a material image used to compose the image 202. Here, it is assumed that P (plural) sheets are prepared. The number P of these material images is generally large enough to prepare the types of colors and textures necessary to form the image 202.
[0015]
Here, for the sake of explanation, the size of each of the P material images 203 is set to the same size as the tile area. However, the size of each material image does not necessarily need to match the size of the tile area. Also, it is not necessary that all P sheets have the same size. When the size of each material image is different as described above, it is necessary to convert the size of the material image 203 when pasting the image to the corresponding tile area of the image 202. Here, the number of sheets P is a number sufficiently larger than the above-mentioned M × N sheets.
[0016]
FIG. 4 is a diagram showing an example in which the image 201 is divided into 4 × 5 tile areas, where the number of pixels in the horizontal direction of the image 201 is X, the number of pixels in the vertical direction is Y, and the number of pixels in the horizontal direction of each tile area. The number is indicated by p, and the number of pixels in the vertical direction is indicated by q (X = 4p, Y = 5q). Each tile area is indicated by TL (x, y: x = 0 to 3, y = 0 to 4) according to its position.
[0017]
FIG. 5 shows a state where each tile area is composed of red (R), green (G), and blue (B) color planes when the image 201 is a color image.
[0018]
[Color mosaic image generation processing]
FIG. 6 is a flowchart showing a mosaic image generation process by the image processing apparatus according to the present embodiment.
[0019]
First, in step 11, the original image 201 is divided into M × N areas (tile areas). As a result of this division, for example, as shown in FIG. 4 described above, the first image 201 has M × N rectangular tiles TL (0,0), TL (1,0), TL (2,0),. . . . , TL (2, 4) and TL (3, 4). In FIG. 4, X and Y indicate the number of pixels in the horizontal and vertical directions of the image 201, respectively, and p and q indicate the number of pixels in the horizontal and vertical directions of each tile area. Therefore, the following relationship holds: X = p × M, Y = q × N. Here, for the sake of simplicity, it is assumed that all tile areas have the same size, but this is not necessarily required in the present embodiment.
[0020]
FIG. 5 is a diagram showing a data configuration of each tile area. Each pixel of each tile area is decomposed into p × q three primary colors, red (R), green (G), and blue (B).
[0021]
Next, the process proceeds to step S12, and the average density of RGB is calculated for each of the M × N tile areas divided in step S11 according to the following equation.
[0022]
Rd_av = ΣRi / (p × q)
Gd_av = ΣGi / (p × q)
Bd_av = ΣBi / (p × q)
Here, d_av means the average value of the destination (the original image 201). Therefore, each of Rd-av, Gd-av, and Bd-av indicates the average density of each of red, green, and blue in each tile region. Σ indicates the sum of i = 0 to (pq−1).
[0023]
Next, in step S13, the average density of R, G, and B is calculated for each of the P material images 203 according to the following equation, and the average density is stored in the RAM 105. Note that, as described above, if the average density of these material images 203 has been previously obtained and stored in the hard disk device 106 corresponding to each of these material images, this calculation is not necessary. Nor.
[0024]
Rs-av = ΣRi / (p × q)
Gs-av = ΣGi / (p × q)
Bs-av = ΣBi / (p × q)
Here, s-av means an average value of a source (source image 203). Therefore, each of Rs-av, Gs-av, and Bs-av indicates the average density of each of red, green, and blue in each material image. Σ indicates the sum of i = 0 to (pq−1).
[0025]
Next, the process proceeds to step S14, where the counters Xpos (0 ≦ Xpos ≦ M−1) and Ypos (0 ≦ Ypos ≦ N−1) indicating the position of the target tile area are both set to “0”, and the upper left corner of the image 201 The tile area (tile: TL (0, 0)) is set as the processing start position.
[0026]
Next, the process proceeds to step S15, and the material image having the smallest difference from the average density of the target tile area is selected from the P material images 203. In this selection method, for example, the distance ΔE of the RGB3 stimulus values is calculated, and the one with the smallest stimulus value is selected. The evaluation formula is shown below.
[0027]
ΔE = (Rs-av-Rd-av) ＾ 2 + (Gs-av-Gd-av) ＾ 2 + (Bs-av-Bd-av) ＾ 2
Here, “(Rs−av−Rd−av) ＾ 2” represents the square of (Rs−av−Rd−av).
[0028]
Based on this evaluation formula, a material image having the smallest distance ΔE of the RGB three stimulus values is selected from the P material images 203 and pasted to the tile area to be processed.
[0029]
Next, the process proceeds to step S16, in which the tile area of the image 201 to be processed is moved to the next position. In step S17, it is determined whether or not the processing for all the tile areas of the image 201 has been completed. The processes of S15 and S16 are repeatedly executed.
[0030]
[Monochrome mosaic image generation processing]
Next, a case of a monochrome image will be described.
[0031]
FIG. 7 is a flowchart showing a flow of processing for synthesizing a monochrome mosaic image according to the present embodiment.
[0032]
First, in step 61, the image 201 is divided into M × N areas (tile areas). As a result of this division, as shown in FIG. 4, the first image 201 has M × N tiles TL (0,0), TL (1,0), TL (2,0),. , 4), and TL (3, 4).
[0033]
Here, for the sake of simplicity, the sizes of the tile regions are all assumed to be equal, but this is not necessarily required in the present embodiment. FIG. 5 shows the configuration of each tile area. Each tile area is decomposed into p × q three primary colors, red (R), green (G), and blue (B).
[0034]
Next, the process proceeds to step S62, and the average luminance of each of the M × N tile areas divided in step S61 is calculated. Here, the average density of R, G, and B is calculated first in the same manner as in step S12 described above.
[0035]
Rd_av = ΣRi / (p × q)
Gd_av = ΣGi / (p × q)
Bd_av = ΣBi / (p × q)
From this value, the average luminance is calculated based on the following equation.
[0036]
Ys_av = (Rd_av × 77 + Gd_av × 150 + Bd_av × 29 + 128) / 256
Next, the process proceeds to step S63, where the average luminance is calculated for each of the P material images 203. Here, first, the average density of R, G, and B is calculated in the same manner as in step S13 described above.
[0037]
Rs_av = ΣR / (p × q)
Gs_av = ΣGi / (p × q)
Bs_av = ΣBi / (p × q)
From this value, the average luminance is calculated based on the following equation.
[0038]
Ys_av = (Rs_av × 77 + Gs_av × 150 + Bs_av × 29 + 128) / 256
Next, proceeding to step S64, similarly to step S14, the counters Xpos (0 ≦ Xpos ≦ M−1) and Ypos (0 ≦ Ypos ≦ N−1) indicating the position of the tile area being processed are both set to “ Initialize to 0 ". Here, (Xpos, Ypos) = (0, 0) indicates the tile area at the upper left corner of the image 201.
[0039]
Next, the process proceeds to step S65, and the material image most suitable for the tile area specified by the position counters Xpos and Ypos is selected from the P material images 203. In this selection method, for example, the distance ΔE of the Y stimulus value is calculated, and the one with the smallest stimulus value ΔE is selected. The evaluation formula is shown below.
[0040]
ΔE = | Ys_av−Yd_av |
Based on this evaluation formula, the one with the smallest stimulus value ΔE is selected from the P material images.
[0041]
Next, proceeding to step S66, the selected material image 203 is read from the hard disk 106, decoded, further converted to monochrome, and pasted.
[0042]
Next, the process proceeds to step S67, in which the tile area of the target image 201 is moved to the next tile position. In step S68, it is determined whether the processing for all the tile areas of the image 201 has been completed. , The above-described processes of steps S65 to S68 are repeatedly executed.
[0043]
Note that a monochrome mosaic image can be obtained by converting a color mosaic image created according to the above-described description of FIG. 6 into a monochrome image. However, since extra color information is considered in the process of selecting a material image, the There is a possibility that the quality of the mosaic image to be obtained will deteriorate.
[0044]
On the other hand, as in the present embodiment, a high-quality monochrome mosaic image is generated by comparing the average luminance of each tile region and each material image and selecting the most suitable material image for the target tile region. can do.
[0045]
[Other embodiments]
Instead of deciding whether or not to make a monochrome mosaic image from the beginning as in the present embodiment, whether or not to make a monochrome mosaic image may be automatically determined according to the quality of the created mosaic image. good. In this case, a color mosaic image is first created, and if a mosaic image of sufficient quality cannot be obtained there, a monochrome mosaic image may be obtained.
[0046]
As a criterion for determining the quality of the mosaic image in this case, for example, a well-known S / N ratio is used, and if the S / N ratio of the original image 201 and the formed mosaic image 202 does not reach a certain reference value, it is converted to monochrome. You may do it.
[0047]
The processing in this case is shown in the flowchart of FIG.
[0048]
In FIG. 8, first, at step S71, the S / N ratio of the mosaic image created according to the flowchart of FIG. 6 is checked, and at step S72, it is determined whether the checked S / N ratio is equal to or less than a predetermined reference value. View. If so, the process proceeds to step S73, where the mosaic image is converted to a monochrome image.
[0049]
Further, in the above-described embodiment, when pasting the material images, it is described that each material image is converted to a monochrome image and then pasted to each corresponding tile region. Even after the image is generated, the same result can be obtained even if the entire mosaic image is converted to monochrome.
[0050]
In the above embodiment, the Y average luminance was calculated from the RGB values of the image data of the tile area and the material image. However, if image data originally expressed in the YUV color space like a well-known JPEG image is used, The calculation of the Y average luminance can be omitted.
[0051]
Further, a well-known sepia tone processing is further performed on the created monochrome mosaic image, so that a sepia tone mosaic image can be obtained.
[0052]
As described above, according to the present embodiment, the quality of a mosaic image can be improved.
[0053]
【The invention's effect】
As described above, according to the present invention, it is possible to generate a monochrome mosaic image by performing a process of selecting and pasting a corresponding material image by focusing on a luminance component instead of a color difference component of an original image.
[0054]
Further, according to the present invention, there is an effect that the quality of the obtained mosaic image can be improved.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an image processing apparatus according to an embodiment.
FIG. 2 is a diagram illustrating a mosaic image.
FIG. 3 is a diagram illustrating a process of generating a mosaic image.
FIG. 4 is a diagram illustrating an example in which an original image is divided into tile areas.
FIG. 5 is a diagram illustrating a color configuration of each tile area forming a mosaic image.
FIG. 6 is a flowchart illustrating a flow of a color mosaic image generation process according to the present embodiment.
FIG. 7 is a flowchart illustrating a flow of a monochrome mosaic image generation process according to the present embodiment.
FIG. 8 is a flowchart illustrating a process of converting a color mosaic image into a monochrome mosaic image according to another embodiment of the present invention.

Claims (9)

An image processing apparatus that creates an image imitating an original image by combining a plurality of material images selected from a plurality of material images,
Dividing means for dividing the original image into a plurality of regions;
Calculating means for calculating an average density and an average luminance of each color of each of the plurality of regions divided by the dividing means;
Based on the average density of each color of each of the material image and the average density of each color of calculating said plurality of regions by said calculating means, an image selection means for selecting a material images corresponding to each of the plurality of regions ,
Image pasting means for generating a color image by pasting the material images selected by the image selecting means to the corresponding areas,
Inspection means for inspecting the quality of the color image bonded by the image bonding means,
Means for determining whether or not to convert the color image to monochrome, according to an inspection result by the inspection means,
At the time of the monochrome conversion, the image selection unit is configured to calculate the material image corresponding to each of the plurality of regions based on the average luminance of the plurality of regions and the average luminance of the material image calculated by the calculation unit. An image processing apparatus comprising : selecting a material image, converting the selected material image to monochrome, and pasting the selected material image to a corresponding area to generate a monochrome image . An image processing apparatus that creates an image imitating an original image by combining a plurality of material images selected from a plurality of material images,
Dividing means for dividing the original image into a plurality of regions;
Calculating means for calculating an average density and an average luminance of each color of each of the plurality of regions divided by the dividing means;
Based on the average density of each color of each of the plurality of areas and the average density of each color of the material image calculated by the calculation unit, each of the plurality of areas corresponds to each of the plurality of areas. Image selection means for selecting a material image to be
Image pasting means for generating a color image by pasting the material images selected by the image selecting means to the corresponding areas,
Inspection means for inspecting the quality of the color image bonded by the image bonding means,
Means for determining whether or not to convert the color image to monochrome, according to an inspection result by the inspection means,
At the time of the monochrome conversion, the image selecting unit sets the material image corresponding to each of the plurality of regions based on the average luminance of the plurality of regions and the average luminance of the material image calculated by the calculating unit. And generating a color image by pasting the selected material images to corresponding areas, respectively, and converting the generated color image into a monochrome image. The image processing apparatus according to claim 1 , further comprising a unit configured to convert the monochrome image into a sepia image. An image processing method for creating an image imitating an original image by combining a plurality of material images selected from a plurality of material images,
A dividing step of dividing the original image into a plurality of regions;
A calculating step of calculating an average density and an average luminance of each color of each of the plurality of regions divided in the dividing step;
Based on the average density of each color of each of the material image and the average density of each color of the plurality of areas calculated in the calculating step, an image selection step of selecting the material images corresponding to each of the plurality of regions ,
Image pasting step of pasting the material image selected in the image selecting step to the corresponding area to generate a color image,
An inspection step of inspecting the quality of the color image bonded in the image bonding step,
A step of determining whether or not to convert the color image to monochrome according to the inspection result of the inspection step ,
At the time of the monochrome conversion, in the image selecting step, based on the average luminance of each of the plurality of areas and the average luminance of the material image calculated in the calculating step, the material image corresponding to each of the plurality of areas. And generating a monochrome image by converting the selected material image into a monochrome image and pasting the monochrome image in a corresponding area . An image processing method for creating an image imitating an original image by combining a plurality of material images selected from a plurality of material images,
A dividing step of dividing the original image into a plurality of regions;
A calculating step of calculating an average density and an average luminance of each color of each of the plurality of regions divided in the dividing step;
An image selection step of selecting a material image corresponding to each of the plurality of regions based on the average density of each color of each of the plurality of regions and the average density of each color of the material image calculated in the calculation step; ,
Image pasting step of pasting the material image selected in the image selecting step to the corresponding area to generate a color image,
An inspection step of inspecting the quality of the color image bonded in the image bonding step,
A step of determining whether or not to convert the color image to monochrome according to the inspection result of the inspection step,
At the time of the monochrome conversion, in the image selecting step, a material image corresponding to each of the plurality of areas is based on the average luminance of each of the plurality of areas and the average luminance of the material image calculated in the calculating step. And generating a color image by pasting the selected material images to corresponding regions, and converting the generated color image into a monochrome image. The image processing method according to claim 4, further comprising a step of converting the monochrome image into a sepia image. Combining a plurality of material images selected from a plurality of material images, storing a program for executing an image processing method of creating an image imitating the original image, a computer-readable storage medium,
The program is
Dividing means for dividing the original image into a plurality of regions;
Calculating means for calculating an average density and an average luminance of each color of each of the plurality of regions divided by the dividing means;
An image selection unit that selects a material image corresponding to each of the plurality of regions based on an average density of each color of each of the plurality of regions and an average density of each color of the material image calculated by the calculation unit; ,
Image pasting means for generating a color image by pasting the material images selected by the image selecting means to the corresponding areas,
Inspection means for inspecting the quality of the color image bonded by the image bonding means,
Means for determining whether or not to convert the color image to monochrome, according to an inspection result by the inspection means,
At the time of the monochrome conversion, the image selecting unit sets the material image corresponding to each of the plurality of regions based on the average luminance of the plurality of regions and the average luminance of the material image calculated by the calculating unit. A computer-readable storage medium characterized in that a computer-readable storage medium is selected, and a monochrome image is generated by converting the selected material image into a monochrome image and attaching the monochrome image to a corresponding area. Combining a plurality of material images selected from a plurality of material images, storing a program for executing an image processing method of creating an image imitating the original image, a computer-readable storage medium,
The program is
Dividing means for dividing the original image into a plurality of regions;
The average density of each color of each of the plurality of areas divided by the dividing means Calculating means for calculating the average brightness and average brightness;
An image selection unit that selects a material image corresponding to each of the plurality of regions based on an average density of each color of each of the plurality of regions and an average density of each color of the material image calculated by the calculation unit; ,
Image pasting means for generating a color image by pasting the material images selected by the image selecting means to the corresponding areas,
Inspection means for inspecting the quality of the color image bonded by the image bonding means,
Means for determining whether or not to convert the color image to monochrome, according to an inspection result by the inspection means,
At the time of the monochrome conversion, the image selecting unit sets the material image corresponding to each of the plurality of regions based on the average luminance of the plurality of regions and the average luminance of the material image calculated by the calculating unit. A computer-readable storage medium characterized in that a color image is generated by selecting a selected material image in a corresponding area, and the generated color image is converted into a monochrome image. The computer-readable storage medium according to claim 7, wherein the program further includes a unit configured to convert the monochrome image into a sepia image.

Images