JPH0620044A - Method and device for image processing - Google Patents

Abstract

PURPOSE:To ensure the execution of the effective image processing over an entire due area by using the value of the effective picture elements in a pre scribed area when the value of each picture element is decided based on the value of those picture elements in the prescribed area including the relevant picture element. CONSTITUTION:The value of the noticed picture element included in a set mask area is decided by the two-dimensional space filtering processing. In this case, a picture element is selected in a rectangular area around the noticed picture element. If the selected picture element is included in the mask area, the value of this picture element is used for the two-dimensional space filtering processing operation. If not, the value of the picture element is not used for the operation. When such processing is carried out to all picture elements included in the rectangular area, even such noticed picture element whose rectangular area overflows the mask area can also effectively processed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method and apparatus for performing image processing for determining the value of each pixel in an image based on the value of the pixel in a predetermined area including the pixel.

[0002]

2. Description of the Related Art As a data processing method in a conventional image processing apparatus, there is a processing method of calculating the pixel value of a target pixel based on the pixel values of its surroundings. In such a processing method, the value of the pixel of interest is determined by performing a predetermined calculation by using the pixel value of the pixel existing in the rectangular area specified by the pixel of interest, for example. Examples include spatial filtering processing and smoothing processing.

In the two-dimensional spatial filtering process, a rectangular area having a predetermined size centered on the pixel of interest in the image is set, and the sum of products of each pixel value in this rectangular area and a coefficient designated for each pixel. Calculate. Then, a value obtained by dividing this by the designated scale factor is set as the value of the pixel of interest.

The principle of the two-dimensional spatial filtering process is
This will be described with reference to FIG. Reference numeral 1 is a digitized image, and image 1 is divided into many pixels 2. In this example, the number of pixels 2 is N in the horizontal direction and M in the vertical direction (N and M are both integers greater than 1). The pixel order is
The left end is 0 in the horizontal direction, N-1 is in the right end, and the upper end is 0 in the vertical direction.
When displaying the pixel value specified up to the pixel position by counting so that the lower end becomes M-1, the horizontal direction is xth and the vertical direction is y.
The pixel value of the th will be displayed as a _xy . Each pixel 2 has about 256 gradations, and a smaller number represents a darker color and a larger number represents a brighter color.

Now, as shown in FIG. 4, a rectangular area 21 having n pixels in the horizontal direction and m pixels in the vertical direction with the pixel of interest 22 at the center.
Then, the two-dimensional spatial filtering process is performed (n and m are both odd numbers larger than 1. However, n and m
Must not both be 1). Where n ',
Define m ′ as n ′ = (n−1) / 2 m ′ = (m−1) / 2. n ′ and m ′ correspond to the number of pixels from the target pixel to the left and right ends and the number of pixels to the upper and lower ends, respectively. Then, the coefficients designated for each pixel in the rectangular area of n pixels × m pixels are b _{(-n ') (-m')} , b _{(-n '+ 1) (-m')} , ..., B
_{(n ') (-m')} , b _{(-n ') (-m' + 1)} , b _{(-n '+ 1) (-m' + 1)} , ...,
b _{(n ') (-m' + 1)} , ..., b _{(-n ') (m')} , b _{(-n '+ 1) (m')} ,
, B _{(n ') (m')} , and the scale factor is s.

In this case, the pixel of interest (the coordinate value is x,
If the vertical direction y) is in the central region of the image, the value a of the two-dimensional spatial filtering process can be obtained by performing the following calculation. That is, a = (a _{(x-n ') (y-m')} * b _{(-n ') (-m')} + a _{(x-n '+ 1) (y-m')} * b _{(-n '+1) (-m')} +… + a _{(x + n ') (y-m')} × b _{(n ') (-m')} + a _{(x-n ') (y-m' + 1)} × b _{(-n ') (-m' + 1)} + a _{(x-n '+ 1) (y-m' + 1)} × b _{(-n '+ 1) (-m' + 1)} + ... + a _{(x + n ') (y-m' + 1)} xb _{(n ') (-m' + 1)} + ... + a _{(x-n ') (y + m')} xb _{(-n ') ( m ')} + a _{(x-n' + 1) (y + m ')} xb _{(-n' + 1) (m ')} + ... + a _{(x + n') (y + m ')} xb _{(n ') (m')} ) / s.

In the smoothing process, a rectangular area of a predetermined size centered on the pixel of interest in the image is set,
The average value of the pixel values in this rectangular area is calculated, and this is set as the value of the pixel of interest.

The principle of the smoothing process will be described with reference to FIGS. 3 and 4 similarly to the above-mentioned two-dimensional spatial filtering process. Now, as shown in FIG. 4, smoothing processing is performed in a rectangular region 21 having n pixels in the horizontal direction and m pixels in the vertical direction with the pixel of interest 22 at the center (n and m are both odd numbers larger than 1). However, both n and m must not be 1). Here, n ′ and m ′ are defined as n ′ = (n−1) / 2 m ′ = (m−1) / 2. n ′ and m ′ correspond to the number of pixels from the target pixel to the left and right ends and the number of pixels to the upper and lower ends, respectively.

At this time, if the coordinate value of the pixel of interest is x,
In the case of the vertical direction y, the value a for smoothing processing is obtained by performing the following calculation.

A = (a _{(x-n ') (y-m')} + a _{(x-n '+ 1) (y-m')} + ... + a _{(x + n ') (y-m')} + a _{(x-n ') (y-m' + 1)} + a _{(x-n '+ 1) (y-m' + 1)} + ... + a _{(x + n ') (y-m' + 1)} + ... + A _{(x-n ') (y + m')} + a _{(x-n '+ 1) (y + m')} + ... + a _{(x + n ') (y + m')} ) / (n × m) Becomes

[0011]

In the image processing apparatus of the above-mentioned conventional example, for example, when it is desired to perform the data processing only on a portion other than the main subject of a landscape photograph, or only on the scenery outside the window of the indoor photograph. When the above data processing is performed only on a predetermined area of the original image, for example, when the above data processing is desired, the following is performed.

First, a mask image showing an area where data processing is desired to be performed is created. Next, the above data processing is performed on the entire original image. Finally, only the mask area of the image subjected to the above data processing is combined on the original image.

When this method is used to increase the value of n or m and perform image processing such as two-dimensional spatial filtering processing or smoothing processing in a large rectangular area,
At the boundary portion of the mask area, the pixel value of the area where the image processing is not performed is used. Therefore, there is a problem that an unnatural color appears as a result of the image processing calculation. Particularly in smoothing processing, since the effect of "blurring" is enhanced by increasing the value of n or m, the value of n or m is often set to a large value. And, for example,
In an image with a white house in front of a green forest, if the two-dimensional spatial filtering process or smoothing process is performed on the background forest part, the green of the forest and the white of the house are mixed near the boundary between the house and the forest. Colors appear.

That is, in the conventional image processing apparatus, when the image processing for calculating the value of the target pixel by the value of the peripheral pixel is executed, if the peripheral pixel includes the pixel outside the predetermined area, this effect appears. It will result in an unnatural image.

Further, in the data processing in the conventional image processing apparatus described above, when the pixel of interest is in the peripheral area of the image, a part of the rectangular area of n pixels × m pixels appears outside the image 1, There is a problem that arithmetic processing cannot be performed. For example, FIG. 10 shows a state in which a rectangular area 41 centered on the pixel of interest 4 extends outside the original image 1. As a conventional method for dealing with the pixel of interest in which the rectangular area goes out of the original image, (1) 2 is set for the pixel of interest in which the rectangular area goes out of the image 1. The pixel values of the original image are used as they are without performing dimension filtering. (2) Only the part that has been subjected to the two-dimensional filtering process is cut out from image 1 and used. (3) In the two-dimensional spatial filtering process, the left end of the image is virtually connected to the right end of the image, and the upper end of the image is virtually connected to the lower end of the image. There is.

However, in the above method (1), when the size (n, m) of the rectangular area is increased and the processing is performed on the large rectangular area, the processing is performed on the image obtained as the processing result. There is a problem that the difference between the part and the part that is not done becomes noticeable. Further, the method (2) has a problem that the larger the rectangular area size, the smaller the usable image area. Further, the method (3) has a problem in that the color existing at the edge of the image is used for the calculation on the opposite side of the screen, so that the calculation result is unnatural. For example, if two-dimensional spatial filtering processing or smoothing processing is performed on an image with sky blue on the top and green on the bottom,
At the top edge, a mixture of sky blue and mountain green appears.

The present invention has been made in view of the above problems, and is effective in determining the value of each pixel on the basis of the value of the pixel in the predetermined area including the pixel. It is an object of the present invention to provide an image processing method and apparatus that enables image processing to be performed using pixel values and that enables effective image processing over the entire area in which image processing is to be performed.

[0018]

An image processing apparatus according to the present invention for achieving the above object has the following configuration.
That is, an image processing apparatus that performs image processing that determines the value of each pixel in an image based on the value of a pixel in a predetermined area that includes the pixel, and the area in which the image processing is performed in the image is the execution area Setting means for setting, extraction means for extracting pixels existing in the execution area among pixels existing in the predetermined area, and pixels extracted by the extraction means for each pixel in the execution area And executing means for executing the image processing by using.

An image processing method according to the present invention for achieving the above object has the following configuration. That is, an image processing method for performing image processing for determining the value of each pixel in an image based on the value of a pixel in a predetermined area including the pixel, wherein the area in which the image processing is executed in the image is set as an execution area. A setting step of setting, an extraction step of extracting pixels existing in the execution area among pixels existing in the predetermined area, and a pixel extracted by the extraction step for each pixel in the execution area And an execution step of executing the image processing by using.

[0020]

With the above configuration, when performing the image processing in which the value of each pixel is determined based on the value of the pixel in the predetermined area, only the pixels existing in the predetermined area and in the set execution area are executed. It is possible to execute the image processing by using, and the effective image processing is performed over the entire execution area.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a block diagram showing the schematic arrangement of an image processing apparatus according to the first embodiment. In the figure, 11 is an image input unit. This image input unit 11
The original image input in (4) is sent to the processing unit 12 described later as digital image data. A processing unit 12 performs a two-dimensional spatial filtering process on the image. Further, the processing unit 12 includes the image input unit 11 described above, a storage unit 13, a display unit 14, a command input unit 15,
Image data is transferred and control data is exchanged between the image output unit 16 and the coordinate input unit 17 to control the entire image processing apparatus.

A storage unit 13 stores image data and processing programs. Under the control of the processing unit 12, the image data read by the image input unit 11 is stored in the storage unit 13.
Stored in. Further, the processing program, image data, control data, etc. required in the processing unit 12 are read from the storage unit 13. A display unit 14 displays images and characters. Further, the display unit 14 displays an image according to an instruction from the processing unit 12, displays a processing instruction content from a command input unit 15 described later, or displays a content currently being processed. Further, a coordinate input unit 17 described later
The coordinate position designated by is always displayed on the display unit 14 as the cursor position.

A command input unit 15 includes a keyboard and the like. The command input section 15 is used for command input and parameter specification. An image output unit 16 includes an inkjet printer, a color laser printer, and the like. The image output unit 16 is used to output the image processed by the processing unit 12 as a still image print. The image output unit 16 may be a film output device such as a film recorder. Reference numeral 17 is a coordinate input unit, which is provided with an input device such as a mouse or a digitizer. The position designated by the coordinate input unit 17 is displayed as a cursor position in the display unit 14. The coordinate input unit 17 is used when designating the mask area of the image.

Next, the processing operation of the image processing apparatus having the above configuration will be specifically described with reference to the flowchart of FIG.

First, in step S1, an image is input. In the process of step S1, the original image is read using the image input unit 11, this is input as digital image data, and stored in the storage unit 13 via the processing unit 12. When a photograph or printed matter is used as the original image, the image input unit 11 performs analog / digital conversion while scanning the image using an image sensor such as a CCD like a known film scanner or flatbed scanner. Any device with a function may be used. The image data converted to digital here is stored in the storage unit 13 via the processing unit 12.

If the original image is a three-dimensional object,
You can take a picture of this with a camera in advance and input it using the film scanner described above. When using a video camera, a known video memory device may be used as the image input unit 11. This video memory device is a device for analog / digital conversion of one field or one frame of a video signal and can digitize any one screen of video. Here, the image data converted to digital is stored in the storage unit 13 via the processing unit 12.

When the original image is an already digitized image such as an image created by a computer graphics program, the image input unit 11 directly reads digital data such as that of a known MT device. A device may be used. Here, the read digital image data is stored in the storage unit 13 via the processing unit 12.

As described above, the digitized original image is stored in the storage unit 13. The following description will be made assuming that the original image is the image 1 having N pixels in the horizontal direction and M pixels in the vertical direction as shown in FIG. Further, each pixel has 256 gradations from 0 to 255,
It is assumed that 0 is black and 255 is a monochrome image that represents white.

Next, in step S2, the command input unit 15 inputs parameters. Here, the rectangular area size of the two-dimensional spatial filtering process, the coefficient for each pixel, and the scale factor are set as parameters. When a parameter is input using the command input unit 15, this value is displayed on the display unit 14. Therefore, the operator can recognize the input value by the display on the display unit 14. The following description will be given assuming that the parameters input here are as follows. As the setting values of the rectangular area size, the size in the horizontal direction is n, and the size in the vertical direction is m (n and m are not 1 at the same time, a positive odd number). Also, the coefficients for each pixel are b _{(-n ' ) ( -m')} , b _{(-n '+ 1) ( -m')} , ..., b
_{(n ') (-m')} , b _{(-n ') (-m' + 1)} , b _{(-n '+ 1) (-m' + 1)} , ...,
b _{(n ') (-m' +1)} , ..., b _{(-n ') (m')} , b _{(-n '+ 1) (m')} ,
, B _{(n ') (m')} , and the scale factor is s (where n '= (n-1) / 2, m' = (m-1) / 2).
By the above operation, the pixel of interest 22 as shown in FIG.
A rectangular area 21 of n pixels × m pixels centered at is designated. In FIG. 4, as one specific example of the rectangular area, n =
7 shows a case where m = 5 is set.

Next, in step S3, a mask image is created. Here, the original image 1 input in step S1 is read from the storage unit 13 and displayed on the display unit 14. The operator uses the coordinate input unit 17 (coordinate input device such as a mouse or a digitizer) to
The cursor is moved so as to trace the mask area of the original image displayed on the display unit 14. When the entire mask area is designated in this way, the completed mask image is stored in the storage unit 13. A method of designating an image area (mask area) using the coordinate input unit 17 is known,
The detailed description is omitted here.

In step S4, the target pixel is designated.
Each pixel 2 of the original image 1 of FIG. 3 is sequentially designated as a pixel of interest. Then, the calculation of the two-dimensional spatial filtering for this pixel of interest is performed in the following steps S5 and S6. In the following description, the pixel of interest is the x-th pixel a _xy in the horizontal direction and the y-th pixel in the vertical direction. In step S5, it is determined whether or not the pixel of interest designated in step S4 is a mask area, and if it is within the mask area, the process proceeds to step S6 to execute a two-dimensional spatial filtering process. Further, if it is outside the mask area, it is not necessary to perform the two-dimensional filtering calculation, so that the process proceeds to step S7.

Step S6 is a part for performing a two-dimensional spatial filtering process. Details of the processing of this part are shown in FIG.
This will be described with reference to the flowchart in FIG.

Step S21 is data initialization.
A variable sum for storing the sum of products of pixel values and coefficients and a variable count for storing the sum of coefficients for each pixel are set to 0. That is,
In step S21, the calculation formula sum = 0 count = 0 is executed.

Step S22 is the selection of pixels, in which pixels within a rectangular area having the size set in step S2 are designated in order with the specified pixel of interest as the center, and the following steps S23 to S25 are performed. Process. Here, the relative distance between the selected pixel and the target pixel a _xy designated in step S4 of FIG. 3 is x ′ in the horizontal direction and y ′ in the vertical direction. Therefore, the selected pixel is a _{(x + x ') (y + y')}
Is. A step S23 decides whether or not the pixel selected in the step S22 is within the mask area. If the pixel selected in step S22 is within the mask area, the process proceeds to step S24 to execute a predetermined calculation (described later). Also,
If it is outside the mask area, the process proceeds to step S25 without executing step S24.

Step S24 is an operation when the pixel selected in step S22 is within the mask area, and the value a _{(x + x ') (y + y') of} the pixel selected for the variable sum and The product of the corresponding coefficient b _{(x ') (y')} is added, and the variable count
Add b _{(x ') (y')} to. That is, sum = sum + a _{(x + x ') (y + y')} * b _{(x ') (y')} count = count + b _{(x ') (y')} .

In step S25, it is determined whether or not the above-mentioned processes have been completed for all the pixels in the rectangular area.
If the result of this determination is that there is a pixel that has not yet been processed, the process returns to step S22 and the next pixel is processed. If the processing for all the pixels in the rectangular area is completed, the process proceeds to step S26. The process in step S26 is a two-dimensional spatial filtering operation. The variable s obtained in the processing of steps S21 to S25
The two-dimensional spatial filtering calculation value a is obtained using um and the value of the variable count. The calculation formula used here is a = sum / s ', where s' = s * count / (b _{(-n ') (-m')} + b _{(-n '+ 1) (-m')} + ... + B _{(n ') (-m')} + b _{(-n ') (-m' + 1)} + b _{(-n '+ 1) (-m' + 1)} + ... + b _{(n ') (-m' + 1)} + ... + b _{(-n ') (m')} + b _{(-n '+ 1) (m')} + ... + b _{(n ') (m')} ).

As described above, the two-dimensional spatial filter calculation for the target pixel a _xy set in step S4 is completed, and the calculated value a obtained here is set as the pixel value after the image processing of a _xy .

When the two-dimensional spatial filtering process of step S6 is completed as described above, the process proceeds to step S7. In step S7, it is determined whether the processing of all pixels is completed. If there is a pixel that has not been processed, the process returns to step S4, the next target pixel is designated, and the above-described two-dimensional spatial filtering operation is repeated. If the processing for all the pixels is completed, the process proceeds to step S8 to perform the output processing. In step S8, the created two-dimensional spatial filtering processing image is processed by the image output device 1 of FIG.
6 is used for output. With the above, all processing is completed.

As described above, according to the image processing apparatus of the first embodiment, the two-dimensional spatial filter calculation is executed using only the pixels included in the mask area. The value of the scale factor s is set by the ratio of the sum of the coefficients of the pixels used for the calculation and the sum of the coefficients of all the pixels. By performing the above-described processing, it is possible to obtain an effective image processing result for all the target pixels without the colors outside the mask area being mixed in the two-dimensional spatial filtering processing.

<Second Embodiment> An image processing apparatus according to the second embodiment has the same configuration as that of the first embodiment (FIG. 1). Then, the two-dimensional spatial filtering processing is executed according to the flowchart of FIG. 2, but another method is used in the processing procedure of the two-dimensional spatial filtering calculation in step S6. The processing procedure of the two-dimensional spatial filtering calculation in the second embodiment will be described below with reference to the flowchart of FIG.

Step S31 is data initialization.
A variable sum that puts the combination of the product of the pixel value and the coefficient is set to 0. That is, the arithmetic expression sum = 0 is executed.

In step S32, the pixels are selected. The pixels in the rectangular area centered on the pixel of interest designated in step S4 are designated in order, and the processes from step S33 to step S36 described below are performed. The relative distance between the pixel selected here and the target pixel a _xy designated in step S2 of FIG. 2 is defined as the horizontal direction x ′ and the vertical direction y ′. Therefore, the value of the selected pixel is a _{(x + x ') (y + y')} . Step S3
In 3, it is determined whether the pixel selected in step S32 is within the mask area. Then, step S32
If the pixel selected in step S34 is within the mask area, step S34
If it is outside the mask region, the process proceeds to step S35.

Step S34 is an operation when the pixel selected in step S32 is within the mask area, and the pixel values a _{(x + x ') (y + y')} and b _(x are selected for the variable sum. _{') (y')}
Add the product of and. That is, the calculation of sum = sum + a _{(x + x ') (y + y')} * b _{(x ') (y')} is executed.

On the other hand, steps S35 and S36 are processes to be performed when the pixel selected in step S32 is outside the mask area. First, in step S35, the shortest distance mask pixel is selected. The shortest-distance mask pixel is a pixel in the mask area that is closest to the pixel selected in step S32. Specifically, the distance between the pixel selected in step S32 and all the pixels in the mask area is calculated, and the pixel having the shortest distance among them is set as the shortest distance mask pixel. Then, the pixel value of the mask pixel at the shortest distance (this is referred to as a ′) is obtained in step S
Proceed to 36.

In step S36, the sum calculation is executed using the value a'determined in step S35. That is, for the variable sum, the values a'and b _{(x ') (y')} obtained in step S35
Add the product of and. Therefore, the arithmetic expression is sum = sum + a '* b _{(x') (y ')} .

In step S37, it is determined whether selection and processing have been completed for all pixels in the rectangular area. If there is a pixel that has not been selected yet, the process returns to step S32 and the next pixel is selected and calculation is performed. If all pixels in the rectangular area have been selected and processed, step S38 is performed.
Proceed to. In step S38, the two-dimensional spatial filtering result is calculated. Here, the two-dimensional spatial filtering calculation value a is calculated using the variable sum calculated in steps S31 to S37. The calculation formula at this time is a = sum / s.

As described above, the calculation for the target pixel a _xy set in step S4 of the flowchart of FIG. 2 is completed. In this way, for pixels outside the mask area,
Since the pixel value of the pixel in the mask area at the closest distance is used instead, the colors outside the mask area are not mixed and an effective two-dimensional spatial filtering result can be obtained.

As described above, according to the image processing apparatuses of the first and second embodiments, even when the two-dimensional spatial filtering process is performed only on the area designated by the mask image,
It is possible to obtain an effective two-dimensional spatial filtering processing result over all the target pixels without the color outside the mask area being mixed in.

<Third Embodiment> In a third embodiment, an image processing apparatus for performing smoothing processing will be described. The schematic configuration of the image processing apparatus according to the third embodiment is the same as that of FIG. 1 of the first embodiment, and the description thereof is omitted here. However, in the processing unit 12, smoothing processing is performed on the input original image. Different from the first embodiment.

Next, the procedure of the smoothing processing by the image processing apparatus of the third embodiment will be concretely described with reference to the flowchart of FIG.

First, in step S41, an image is input. The process of step S41 is the step S of the first embodiment.
Since it is the same as No. 1, detailed description thereof will be omitted. The original image will be described below as an image 1 having N horizontal pixels and M vertical pixels as shown in FIG. In addition, each pixel is assumed to be a monochrome image having 256 gradations from 0 to 255, 0 being black and 255 being white.

Next, in step S42, the command input unit 15 inputs parameters. Here, the rectangular area size for smoothing processing is set as a parameter. When a parameter is input using the command input unit 15, this value is displayed on the display unit 14. Therefore, the operator can recognize the input value by the display on the display unit 14. The following description will be made assuming that the parameter input here, that is, the setting value of the rectangular area size, has a horizontal size of n and a vertical size of m (n and m are not 1 at the same time, a positive odd number). By the above operation, the n × m rectangular area 21 as shown in FIG. 4 is designated. Also, FIG.
In, n ′ and m ′ are n ′ = (n−1) / 2 and m ′ = (m−1) / 2.

Next, in step S43, a mask image is created (processing similar to step S3 of the first embodiment),
In the subsequent step S44, the pixel of interest is designated (the same process as step S4 in the first embodiment). Then, the smoothing calculation for the target pixel is performed in the following steps S45,
This is performed in step S46. In the description below, it is assumed that the pixel of interest is the x-th pixel ax _y in the horizontal direction and the y-th pixel in the vertical direction. A step S45 decides whether or not the pixel of interest designated in the step S44 is a mask region, and if it is within the mask region, the process advances to a step S46 to execute a smoothing calculation. Further, if it is outside the mask area, it is not necessary to perform the smoothing calculation, so that the process proceeds to step S47.

Step S46 is a part for performing smoothing processing. Details of the processing of this part will be described with reference to the flowchart of FIG.

In FIG. 8, step S51 is data initialization, in which a variable sum for storing the total pixel value and a variable count for counting the number of pixels in the mask area are set to 0. That is, in step S51, the calculation formula sum = 0 count = 0 is executed.

Step S52 is the selection of pixels, in which the pixels in the rectangular area having the size set in step S42 are sequentially specified with the specified pixel of interest as the center, and the following steps S53 to S55 are executed. Process.
Here, the relative distance between the selected pixel and the pixel of interest a _xy specified in step S44 is calculated as the horizontal direction x ′ and the vertical direction y ′.
And Therefore, the value of the selected pixel is a _{(x + x ') (y + y')} . A step S53 decides whether or not the pixel selected in the step S52 is within the mask area. If the pixel selected in step S52 is within the mask area, the flow advances to step S54 to execute a predetermined calculation (described later). Also,
If it is outside the mask area, the process proceeds to step S55 without executing step S54.

Step S54 is an operation when the pixel selected in step S52 is in the mask area, and the value a _{(x + x ') (y + y')} of the selected pixel is added to the variable sum to obtain a variable. Add one count. That is, the arithmetic expression sum = sum + a _{(x + x ') (y + y')} count = count + 1 is executed.

In step S55, it is determined whether or not the above-mentioned processes have been completed for all the pixels in the rectangular area.
If the result of this determination is that there is a pixel that has not yet been processed, the process returns to step S52 and the next pixel is processed. If the processing for all the pixels in the rectangular area is completed, the process proceeds to step S56. The process in step S56 is the calculation of the smoothing result. Step S
The smoothing calculation value a is obtained using the values of the variable sum and the variable count obtained in steps 51 to S55. The calculation formula used is s = sum / count.

Thus, the two-dimensional spatial filter calculation for the pixel of interest set in step S44 is completed.

Returning again to the flowchart of FIG. 7, the processing of step S47 and thereafter is executed. In step S47, it is determined whether or not all the pixels have been processed. If there is any unprocessed pixel, the process returns to step S44, the next target pixel is designated, and the smoothing calculation is repeated. If the processing for all pixels is completed, the process proceeds to step S48. In step S48, the image output device 16 is used to output the created smoothing-processed image, and all the processes are completed.

As described above, according to the image processing apparatus of the third embodiment, since the calculation for obtaining the average value is performed using only the pixels included in the mask area, the color outside the mask area is calculated. Is not mixed, and an effective smoothing result can be obtained for all the target pixels.

<Embodiment 4> An image processing apparatus according to Embodiment 4 has the same configuration as that of Embodiment 3 (FIG. 1). Then, the smoothing process is also executed according to the flowchart of FIG. 7, but another method is used in the processing procedure of the smoothing calculation executed in step S46. less than,
The processing procedure of the smoothing calculation in the fourth embodiment will be described with reference to the flowchart of FIG.

In FIG. 9, step S61 is data initialization, and a variable sum for putting the sum of pixel values is set to zero. That is, the arithmetic expression sum = 0 is executed.

Step S62 is the selection of pixels, as shown in FIG.
The pixels in the rectangular area centered on the pixel of interest designated in step S44 are designated in order, and the following step S6 is performed.
The processing from 3 to step S66 is performed. The pixel selected here and the target pixel a designated in step S44 of FIG.
The relative distance to _xy is _x'in the horizontal direction and y'in the vertical direction. Therefore, the value of the selected pixel is a _{(x + x ') (y + y')} . A step S63 decides whether or not the pixel selected in the step S62 is within the mask area. If the pixel selected in step S62 is within the mask region, the process proceeds to step S64, and if it is outside the mask region, the process proceeds to step S65.

Step S64 is an operation when the pixel selected in step S62 is within the mask area, and the value a _{(x + x ') (y + y')} of the selected pixel is added to the variable sum. That is, the calculation of sum = sum + a _{(x + x ') (y + y')} is executed.

On the other hand, steps S65 and S66 are processes to be performed when the pixel selected in step S62 is outside the mask area. First, in step S65, the shortest distance mask pixel is selected. The shortest distance mask pixel is the pixel in the mask area that is closest to the pixel selected in step S62. Specifically, the distance between the pixel selected in step S62 and all the pixels in the mask area is obtained, and the pixel having the shortest distance among them is set as the shortest distance mask pixel. Then, the pixel value of the mask pixel at the shortest distance (this is referred to as a ′) is obtained in step S
Proceed to 66.

In step S66, the sum calculation is executed using the value a'determined in step S65. That is, the value a ′ obtained in step S65 is added to the variable sum. Therefore, the arithmetic expression is: sum = sum + a '.

In step S67, it is determined whether selection and processing have been completed for all pixels in the rectangular area. If there is a pixel that has not been selected yet, the process returns to step S62 and the calculation for the next pixel is performed. When the selection and processing of all pixels in the rectangular area are completed, the process proceeds to step S68. Step S68 is an operation of the smoothing result, and the variable s obtained in steps S61 to S67
The smoothing calculation value a is obtained using um. The calculation formula at this time is a = sum / (n × m).

As described above, the calculation for the target pixel set in step S44 of the flowchart of FIG. 7 is completed. As described above, since the pixel value of the pixel in the mask area at the closest distance is substituted for the pixel outside the mask area, the colors outside the mask area are not mixed and the effective smoothing is performed. The result can be obtained.

As described above, according to the image processing apparatuses of the third and fourth embodiments, even when the smoothing process is performed only on the area designated by the mask image, the color outside the mask area is not mixed. It becomes possible to obtain an effective smoothing processing result.

<Embodiment 5> In the present embodiment 5, when the pixel of interest is in the peripheral portion of the original image and a part of the rectangular area goes out of the image, it is effective for this pixel of interest. An image processing device that enables data processing will be described.

In the image processing apparatus according to the fifth embodiment, the pixel value of the portion of the rectangular area included in the image is used for the pixel of interest in which a part of the rectangular area extends out of the image. And calculate. The image processing apparatus according to the fifth embodiment will be described below.

FIG. 11 is a block diagram showing the schematic arrangement of the image processing apparatus of the fifth embodiment. The configuration of the image processing apparatus is the same as that of the first embodiment (FIG. 1), and the description thereof will be omitted.
In the fifth embodiment, the coordinate input unit 17 is unnecessary (since a mask image is not created).

Next, the image processing procedure of the fifth embodiment will be described with reference to the flowchart of FIG.

In step S71, an image is input.
The details are the same as step S1 of the first embodiment, and here,
The description is omitted. The original image input here is composed of N pixels × M pixels as shown in FIG. That is, there are 0 to (N-1) th pixels in the horizontal direction and 0 to (M-1) th pixels in the vertical direction.

Next, in step S72, the command input unit 15 inputs parameters. This step is also the same as step S1 of the first embodiment, and detailed description thereof will be omitted. The following description will be given assuming that the parameters input here are as follows. As the setting values of the rectangular area size, the size in the horizontal direction is n, and the size in the vertical direction is m (n and m are not 1 at the same time, a positive odd number). In addition, the coefficient for each pixel is b _{(-n ') (-m')} ,
b _{(-n '+ 1) (-m')} , ..., b _{(n ') (-m')} , b _{(-n ') (-m' + 1)} ,
b _{(-n '+ 1) (-m' + 1)} , ..., b _{(n ') (-m' + 1)} , ..., b
_{Let (-n ') (m')} , b _{(-n '+ 1) (m')} , ..., b _{(n ') (m')} be the scale factor (note that n '= (n -1) /
2, m '= (m-1) / 2). By the above operation, the rectangular area 21 of n pixels × m pixels as shown in FIG. 4 is designated for each pixel.

In step S73, the pixel of interest is designated.
Each pixel 2 of the original image 1 of FIG. 10 is sequentially designated as a pixel of interest. Then, the calculation of the two-dimensional spatial filtering for this target pixel is performed in the following steps S74 to S86. In the following description, the pixel of interest is the x-th pixel a _xy in the horizontal direction and the y-th pixel in the vertical direction.

In step S74, it is determined whether or not the left end of the rectangular area formed around the pixel of interest is inside the original image 1. According to this determination, the process proceeds to step S76 if inside, and to step S75 if outside. The determination in step S74 is performed by the following conditional expression: if x−n ′ <0, proceed to step S75. If x−n ′ ≧ 0, proceed to step S76. Then, in steps S75 and S76, the distance from the target pixel to the leftmost pixel used for the calculation is set in the variable xs.

Step S75 is a process when the left end of the rectangular area is out of the image 1, and the distance between the pixel of interest and the left end pixel of the image 1 (the 0th pixel a _{0y in the} horizontal direction) is assigned to the variable xs. To do. Therefore, this process executes the arithmetic expression xs = x (the target pixel is the x-th pixel in the horizontal direction). On the other hand, step S7
6 is a process when the left end of the rectangular area is inside the image 1, and the distance between the pixel of interest and the left end pixel of the rectangular area is xs.
To. Therefore, this process executes the arithmetic expression xs = n '.

In step S77, it is determined whether the right end of the rectangular area is inside the image 1. If it is inside, it proceeds to step S79, and if it is outside, it proceeds to step S78. If the conditional expression for the determination in step S77 is: x + n '> N-1, go to step S78 If x + n'≤N-1, go to step S79. Then, in steps S78 and 79, a variable x indicating the distance from the pixel of interest to the rightmost pixel used for the calculation
Set e.

Step S78 is a process when the right end of the rectangular area extends beyond the image 1, and the pixel of interest and the image 1 are detected.
The distance from the rightmost pixel (the _(N-1) th pixel a _{(N-1) y in the} horizontal direction) is substituted for xe. Therefore, this process is represented by xe = N-1-x. On the other hand, in step S79, the processing is performed when the right end of the rectangular distance is inside the image 1, and the distance between the pixel of interest and the right end pixel of the rectangular area is substituted for xe. Therefore, the arithmetic expression xe = n 'is executed.

Next, in step S80, it is determined whether the upper end of the rectangular area is inside the image 1. According to this determination, the process proceeds to step S82 if it is inside, and to step S81 if it is outside. Specifically, if y−m ′ <0, the process proceeds to step S81, and if y−m ′ ≧ 0, the process proceeds to step S82. Then, step S8
In 1 and 82, the distance from the pixel of interest to the upper end pixel used for calculation is set in the variable ys.

Step S81 is a process when the upper end of the rectangular area extends beyond the image 1, and the variable ys is set to
The pixel of interest and the top pixel of image 1 (the 0th pixel a in the vertical direction
Substitute the distance from _x0 ). Therefore, the arithmetic expression in this processing is ys = y. On the other hand, step S82 is processing when the upper end of the rectangular area is inside the image 1, and the distance between the pixel of interest and the upper end pixel of the rectangular area is substituted into the variable ys. Therefore, the arithmetic expression in this processing is ys = m '.

Next, a step S83 decides whether or not the lower end of the rectangular area is inside the image 1. If it is inside, it proceeds to step S85, and if it is outside, it proceeds to step S84. Specifically, if y + m ′> M−1, the process proceeds to step S84, and if y + m ′ ≦ M−1, the process proceeds to step S85. Then, step S8
In 4 and 85, the distance from the target pixel to the lower end pixel used for the calculation is set in the variable ye.

Step S84 is a process when the lower end of the rectangular area extends from the image 1, and the variable ye is set to the target pixel and the lower end pixel of the image 1 (the (M-1) th pixel in the vertical direction (p _{x ( M -1)} )) Substitute the distance from Therefore, the arithmetic expression in this processing is ye = M-1-y. On the other hand, step S85 is processing when the lower end of the rectangular area is inside the image 1, and the distance between the pixel of interest and the lower end pixel of the rectangular area is substituted into the variable ye. Therefore, the following arithmetic expression ye = m 'is executed.

The above steps S74 to S85
By the processes up to, it is guaranteed that the area specified by xs, xe, ys, and ye within the rectangular area of n pixels × m pixels centering on the target pixel is included in the image 1. Specifically, [xs-th pixel to the left from the pixel of interest] to [xe-th pixel to the right of the pixel of interest] and [ys-th pixel above the pixel of interest]-[ye-th pixel below the pixel of interest] The area formed by [pixels] is always inside the original image 1.

Next, in step S86, the two-dimensional spatial filtering process is executed on the area specified by the above-mentioned xs, xe, ys, and ye. That is, the following arithmetic expression is executed.

A = (a _{(x-xs) (y-ys)} × b _{(-xs) (-ys)} + a _{(x-xs + 1) (y-ys)} × b _{(-xs + 1) (- ys)} ＋… ＋ a _{(x + xe) (y-ys)} × b _{(xe) (-ys)} + a _{(x-xs) (y-ys + 1)} × b _{(-xs) (-ys + 1)} + a _{(x-xs + 1) (y-ys + 1)} xb _{(-xs + 1) (-ys + 1)} + ... + a _{(x + xe) (y-ys + 1)} xb _{(xe) (- ys + 1)} + ... + a _{(x-xs) (y + ye)} xb _{(-xs) (ye)} + a _{(x-xs + 1) (y + ye)} xb _{(-xs + 1) (ye)} + ... + a _{(x + xe) (y + ye)} xb _{(xe) (ye)} ) / s 'However, s' = _sx (b _{(-xs) (-ys)} + b _{(-xs + 1) ( -ys)} + ... + b _{(xe) ( -ys )} + b _{(-xs) (-ys + 1)} + b _{(-xs + 1) (-ys + 1)} + ... + b _{(xe) (-ys + 1)} + … + B _{(-xs) (ye)} + b _{(-xs + 1) (ye)} +… + b _{(xe) (ye)} ) / (b _{(-n ') (-m')} + b _{(-n '+ 1) (-m ')} + ... + b _{(n') (-m ')} + b _{(-n') (-m '+ 1)} + b _{(-n' + 1) (-m '+ 1)} + ... + b _{(n ') (-m' + 1)} + ... + b _{(-n ') (m')} + b _{(-n '+ 1) (m')} + ... + b _{(n ') (m')} ).

This two-dimensional spatial filtering calculation value a
Is set to the pixel value of the corresponding pixel of the output image, and the calculation for this pixel is completed.

In step S87, it is determined whether each of the above-described processes has been completed for all the pixels of the image 1. If there is an unprocessed pixel, the process returns to step S73, the next target pixel is designated, and the two-dimensional spatial filtering operation is repeated. If the processing is completed for all pixels, the process proceeds to step S88. In step S88, the image output unit 16
Thus, the two-dimensional spatial filtering processing image created by this processing is output. This is the end of the process.

As described above, according to the image processing apparatus of the fifth embodiment, it is determined whether or not the rectangular area of the two-dimensional spatial filtering process extends over the image 1, and only the pixels in the internal area of the image 1 are used for the two-dimensional processing. Performs spatial filtering operations. Therefore, unlike the conventional image processing apparatus, it is not possible to process the end portion of the image and the color on the opposite side of the image is not mixed, and effective two-dimensional spatial filtering processing can be performed on the entire image. .

<Embodiment 6> Embodiment 6 shows another example of an image processing apparatus which enables effective two-dimensional spatial filtering processing for a pixel of interest protruding from a rectangular area as in Embodiment 5.

The schematic configuration of the image processing apparatus of the sixth embodiment is similar to that of the fifth embodiment. The two-dimensional spatial filtering processing by the image processing apparatus of the sixth embodiment will be described below with reference to the flowchart of FIG.

In step S91, an original image is input. This is the same as step S71 of the fifth embodiment described above, and the description thereof is omitted. In step S92, parameters are input. This processing is also the step S of the fifth embodiment.
Similar to 72. The parameters set here will be described below. As the setting value of the rectangular area size, the horizontal size is n and the vertical size is m.
(N and m are not 1 at the same time, a positive odd number). In addition, the coefficient for each pixel is b _{(-n ') (-m')} ,
b _{(-n '+ 1) ( -m')} , ..., b _{(n ' ) ( -m')} , b _{(-n ') ( -m ' + 1)} ,
b _{(-n '+ 1) (-m' + 1)} , ..., b _{(n ') (-m' + 1)} , ..., b
_{Let (-n ') (m')} , b _{(-n '+ 1) (m')} , ..., b _{(n ') (m')} be the scale factor (note that n '= (n -1) /
2, m '= (m-1) / 2). By the above operation, FIG.
A rectangular area 21 of m pixels × n pixels is designated as shown in FIG.

Next, in step S93, image expansion processing is performed. The expansion of this image will be described with reference to FIG. In this expansion processing, an area of n'pixels is expanded in the horizontal direction of the original image 1 and m'in the vertical direction.
Expand the pixel area. Then, the pixel value of the original image 1 closest in distance is substituted as the value of each expanded pixel. Therefore, the pixel value at the upper left corner of the original image (0th pixel value in the horizontal direction and 0th pixel value in the vertical direction a ₀₀ ) is assigned to each pixel of the area 31. Similarly, the pixel value a _{(N-1) 0 at the} upper right end of the original pixel is set in each pixel of the area 33, and the pixel value a _{(N-1) 0 at the} lower right end of the original image is set in each pixel of the area 35.
_{(N-1) (M-1)} is assigned to the pixel a _{0 (M-1)} at the lower left corner of the original image in each pixel of the area 37. Further, in the area 32, the pixel values (a ₀₀ to
a _{(N-1) 0} ) are respectively substituted. Similarly, area 3
4 shows the pixel value of the rightmost column of the original image in the area 36
Is assigned to the pixel value of the lowermost first column of the original image, and the region 38 is assigned to the pixel value of the first leftmost column of the original image.

By the above processing, the rectangular areas of all the target pixels in the original image can be accommodated inside the expanded screen.

In step S94, the target pixel is set. This sequentially specifies each pixel of the original image 1 inside the expanded image. Hereinafter, the pixel of interest will be described as the x-th pixel in the horizontal direction and the y-th pixel in the vertical direction.

In step S95, a two-dimensional spatial filtering process is executed. In the sixth embodiment, pixels always exist in the rectangular area of n pixels × m pixels centering on the pixel of interest, so the following calculation formula: a = (a _{(x-n ') (y-m')} × b _{(-n ') (-m')} + a _{(x-n '+ 1) (y-m')} × b _{(-n '+ 1) (-m')} +… + a _{(x + n ') (y-m ')} xb _{(n') (-m ')} + a _{(x-n') (y-m '+ 1)} xb _{(-n') (-m '+ 1)} + a _{(x- n '+ 1) (y-m' + 1)} xb _{(-n '+ 1) (-m' + 1)} + ... + a _{(x + n ') (y-m' + 1)} xb _{(n ') (-m' + 1)} ＋… ＋ a _{(x-n ') (y + m')} × b _{(-n ') (m')} + a _{(x-n '+ 1) (y + m')} × b _{(-n '+ 1) (m')} + ... + a _{(x + n ') (y + m')} × b _{(n ') (m')} ) / s The calculated value a of the two-dimensional spatial filtering a Can be asked.

In step S96, it is determined whether the processing has been completed for all pixels of the original image. If unprocessed pixels remain, the process returns to step S94, the next target pixel is designated, and the two-dimensional spatial filtering operation is repeated. Also, if processing has been completed for all pixels,
It proceeds to step S97. In step S97, the image output unit 16 outputs the two-dimensional spatial filtering processing image created by this processing. This is the end of the process.

As described above, according to the image processing apparatus of the sixth embodiment, the image area is expanded in advance so that the pixels always exist in the rectangular area of the two-dimensional spatial filtering.
Therefore, even if the pixel of interest is at the end of the original image, it is possible to execute the calculation of the two-dimensional spatial filtering as usual. Since the pixel value of the original image closest in distance is assigned to the expanded image area, it is possible to prevent unnatural color from being mixed in the calculation result.

As described above, according to the image processing devices of the fifth and sixth embodiments, even when the two-dimensional spatial filtering process is executed with a large rectangular size, the calculation is executed for all the pixels up to the peripheral part. be able to. Further, it is possible to obtain an effective result of the two-dimensional spatial filtering process without the unnatural color being mixed in.

<Embodiment 7> In the present embodiment 7, when the pixel of interest is in the peripheral portion of the original image and a part of the rectangular area goes out of the image, it is effective for this pixel of interest. An image processing apparatus that enables smoothing processing will be described.

In the image processing apparatus according to the seventh embodiment, the pixel value of the portion of the rectangular area included in the image is used for the pixel of interest in which a part of the rectangular area extends out of the image. Smoothing calculation. The image processing apparatus according to the seventh embodiment will be described below.

The schematic configuration of the image processing apparatus according to the seventh embodiment is similar to that of the fifth embodiment, and the description thereof is omitted here.

Next, the image processing procedure of the seventh embodiment will be described with reference to the flowchart of FIG.

In step S101, an image is input. The details are the same as step S71 of the fifth embodiment, and the description thereof is omitted here. The following description will be made assuming that the original image input in step S101 is the original image 1 having N pixels in the horizontal direction and M pixels in the vertical direction as shown in FIG. Also, each pixel is from 0 to 255
It is assumed that the monochrome image has 256 gradations up to 0, 0 is black and 255 is white.

Next, in step S102, the command input unit 15 inputs parameters. The process of step S102 is also the same as that of step S72 in the fifth embodiment, but the parameter set here is the rectangular area size for the smoothing process. The following description will be given assuming that the parameter input here, that is, the rectangular area size, has a horizontal size of n and a vertical size of m (n and m are not 1 at the same time, a positive odd number). By the above operation, the rectangular area 21 of n pixels × m pixels is designated as shown in FIG. 4 (where n ′ = (n−1) / 2, m ′).
= (M-1) / 2).

Step S103 is the designation of the pixel of interest, and each pixel 2 of the image 1 of FIG. 10 is designated in order as the pixel of interest. Then, the smoothing calculation for the target pixel is performed in the following steps S104 to S11.
Do in 6. In the following description, the pixel of interest is the x-th pixel a _xy in the horizontal direction and the y-th pixel in the vertical direction.

The processing from step S104 to step S115 is the same as the processing from step S74 to step S85 in the above-described fifth embodiment, and the description thereof is omitted.

As in the fifth embodiment, by performing the processing from step S104 to step S115, xs, xe, y in the rectangular area of n pixels × m pixels centering on the pixel of interest.
The area specified by s and ye is guaranteed to be inside the image 1. Then, in step S116, the smoothing process is performed by the above-mentioned xs, xe, ys,
Perform on the area specified by yes. That is, a = (a _{(x-xs) (y-ys)} + a _{(x-xs + 1) (y-ys)} + ... + a _{(x + xe) (y-ys)} + a _{(x-xs) (y -ys + 1)} + a _{(x-xs + 1) (y-ys + 1)} + ... + a _{(x + xe) (y-ys + 1)} + ... + a _{(x-xs) (y + ye)} + a ₍ The arithmetic expression of _{x-xs + 1) (y + ye)} + ... + a _{(x + xe) (y + ye)} ) / ((xs + xe + 1) × (ys + ye + 1)) is executed.

By setting this smoothing calculation value a as the pixel value of the corresponding pixel a _xy of the output image, the calculation for this pixel is completed.

In step S117, it is determined whether or not each of the above-mentioned processes has been completed for all the pixels of the image 1. If there is an unprocessed pixel, the process returns to step S103, the next pixel of interest is designated, and the smoothing calculation is repeated. If the processing is completed for all pixels, step S1
Proceed to 18. In step S118, the image output unit 16 outputs the smoothing-processed image created in this process. This is the end of the process.

As described above, according to the image processing apparatus of the seventh embodiment, it is determined whether or not the rectangular area of the smoothing process extends over the image 1, and the smoothing operation is performed only on the pixels in the internal area of the image 1. There is. Therefore, unlike the conventional image processing apparatus, it is possible to prevent the edge portion of the image from being processed and the color on the opposite side of the image to be mixed in, and it is possible to perform effective smoothing processing on the entire image.

<Embodiment 8> Embodiment 8 shows another example of an image processing apparatus capable of performing effective smoothing processing on a target pixel protruding from a rectangular area, as in Embodiment 7.

The schematic configuration of the image processing apparatus of the eighth embodiment is similar to that of the seventh embodiment. The smoothing process performed by the image processing apparatus according to the eighth embodiment will be described below with reference to the flowchart of FIG.

In step S121, the original image is input. This is step S1 in the above-described seventh embodiment.
Since it is the same as 01, the description is omitted. Here, the following description will be made assuming that the input image is the original image 1 having N pixels in the horizontal direction and M pixels in the vertical direction as shown in FIG. Further, each pixel has 256 gradations from 0 to 255,
It is assumed that 0 is black and 255 is a monochrome image that represents white.

In step S122, parameters are input. This processing is also similar to step S102 of the seventh embodiment. The parameter set here, that is, the rectangular area size, will be described assuming that the horizontal size is n and the vertical size is m (n and m are not 1 at the same time, a positive odd number). By the above operation, the rectangular area 21 as shown in FIG. 4 is designated (however, n ′ = (n−1) / 2,
m '= (m-1) / 2).

Next, in step S123, the image is expanded. This image expansion processing is the same processing as step S93 in FIG. 13 of the sixth embodiment, and the description thereof is omitted here. By this expansion processing, the rectangular areas of all the target pixels in the original image are accommodated inside the expanded screen.

In step S124, the target pixel is set. This sequentially specifies each pixel of the original image 1 inside the expanded image. In the following description, the target pixel is the x-th pixel in the horizontal direction and the y-th pixel in the vertical direction, a _xy .

In step S125, smoothing processing is executed. In the fourth embodiment, focusing on the pixel of interest,
Since pixels always exist in a rectangular area of n pixels × m pixels, the following calculation formula is used: a = (a _{(x-n ') (y-m')} + a _{(x-n '+ 1) (y-m ')} ＋… ＋ a _{(x + n') (y-m ')} ＋ a _{(x-n') (y-m '+ 1)} ＋ a _{(x-n' + 1) (y-m '+ 1)} ＋ … + A _{(x + n ') (y-m' + 1)} +… + a _{(x-n ') (y + m')} + a _{(x-n '+ 1) (y + m')} +… + a _{( x + n ′) (y + m ′)} ) / (n × m) can be used to obtain the smoothing operation value a.

In step S126, it is determined whether the processing has been completed for all the pixels of the original image. If unprocessed pixels remain, the process returns to step S124,
The smoothing calculation is repeated by designating the next target pixel.
If the processing has been completed for all pixels, the process proceeds to step S127. In step S127, the image output unit 1
From 6, the smoothing processed image created by this processing is output. This is the end of the process.

As described above, according to the image processing apparatus of the eighth embodiment, the image area is expanded in advance so that the pixels always exist in the smoothing rectangular area. For this reason,
Even if the pixel of interest is at the edge of the original image, the smoothing operation can be executed normally. Since the pixel value of the original image closest in distance is assigned to the expanded image area, it is possible to prevent unnatural color from being mixed in the calculation result.

As is clear from the above description, according to the image processing devices of the seventh and eighth embodiments, even when the smoothing process is executed with a large rectangular size, the calculation is executed for all the pixels up to the peripheral part. be able to. Further, it is possible to obtain an effective result of the smoothing processing without causing unnatural color to be mixed.

In each of the above embodiments, a monochrome image is described as an example, but in the case of a color image, the same effect can be obtained by repeating the same calculation three times for each of the three primary colors.

In the above embodiment, the rectangular area is
We used an odd number of pixels in both the horizontal and vertical directions, but if the number was even, the pixel of interest would be slightly displaced from the center, so the number of pixels on the left and right sides, and the number of pixels on the upper and lower sides would differ. Yes, it is possible to perform similar processing.

Further, in the above-described first to fourth embodiments, the operator uses the coordinate input device 17 to input the mask image to the display device 1.
Although the designation was made while looking at No. 4, if there is a mask image created in advance, it may be inputted using the image input device 11 in the same manner as the original image.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. It goes without saying that the present invention can also be applied to the case where it is achieved by supplying a system or apparatus with a program for executing the processing defined by the present invention.

[0129]

As described above, according to the image processing method and apparatus of the present invention, when the value of each pixel is determined based on the value of the pixel within the predetermined area including the pixel, the predetermined area is determined. It becomes possible to execute the image processing by using the effective pixel value in the image, and the effective image processing can be executed over the entire area where the image processing should be executed.

[0130]

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an image processing device according to first to fourth embodiments.

FIG. 2 is a flowchart illustrating a procedure of a two-dimensional spatial filtering process performed by the image processing apparatuses according to the first and second embodiments.

FIG. 3 is a diagram for explaining a target pixel in an image and its rectangular area.

FIG. 4 is a diagram showing a rectangular area.

FIG. 5 is a flowchart showing a calculation procedure by a two-dimensional spatial filtering process according to the first embodiment.

FIG. 6 is a flowchart showing a calculation procedure by a two-dimensional spatial filtering process according to the second embodiment.

FIG. 7 is a flowchart illustrating a procedure of smoothing processing performed by the image processing apparatuses according to the third and fourth embodiments.

FIG. 8 is a flowchart illustrating a calculation procedure by smoothing processing according to the third exemplary embodiment.

FIG. 9 is a flowchart illustrating a calculation procedure by smoothing processing according to the fourth exemplary embodiment.

FIG. 10 shows a relationship between a pixel of interest in an image and its rectangular area,
6A and 6B are diagrams illustrating a state in which a rectangular area extends beyond an image.

FIG. 11 is a block diagram showing a schematic configuration of an image processing apparatus according to Examples 5 to 8.

FIG. 12 is a flowchart illustrating a procedure of a two-dimensional spatial filtering process performed by the image processing apparatus according to the fifth exemplary embodiment.

FIG. 13 is a flowchart showing a procedure of two-dimensional spatial filtering processing by the image processing apparatus of the sixth embodiment.

FIG. 14 is a diagram illustrating an extension process.

FIG. 15 is a flowchart illustrating a procedure of a two-dimensional spatial filtering process performed by the image processing device according to the seventh embodiment.

FIG. 16 is a flowchart showing a procedure of two-dimensional spatial filtering processing by the image processing apparatus of the eighth embodiment.

[Explanation of symbols]

 11 image input unit 12 processing unit 13 storage unit 14 display unit 15 command input unit 16 image output unit 17 coordinate input unit

Claims (14)

[Claims] 1. An image processing apparatus for performing image processing for determining a value of each pixel in an image based on a value of a pixel in a predetermined area including the pixel, wherein an area for executing the image processing in the image is Setting means for setting as an execution area, extraction means for extracting pixels existing in the execution area among pixels existing in the predetermined area, and extraction by the extraction means for each pixel in the execution area An image processing apparatus comprising: an executing unit that executes the image processing using the generated pixels. 2. An image processing apparatus for performing image processing for determining a value of each pixel in an image based on a value of a pixel in a predetermined area including the pixel, wherein an area for performing the image processing in the image is Setting means for setting as the execution area, and setting means for resetting the value of the pixel existing outside the execution area among the pixels existing in the predetermined area based on the value of the pixel existing in the execution area, An image processing apparatus comprising: an execution unit that executes the image processing by using all the pixels in the predetermined area for each pixel in the execution area. 3. The setting means sets the values of pixels existing outside the execution area among pixels existing in the predetermined area,
The image processing apparatus according to claim 2, wherein the image processing apparatus is reset based on a value of a pixel closest to the pixel existing in the predetermined area and in the execution area. 4. An image processing apparatus for performing image processing for determining a value of each pixel in an image based on a value of a pixel in a predetermined area including the pixel, the portion of the predetermined area protruding from the image. An image processing apparatus comprising: a setting unit configured to set a remaining region obtained by removal as an execution region; and an execution unit configured to execute the image processing using pixels in the execution region. 5. An image processing apparatus for performing image processing for determining a value of each pixel in an image based on a pixel value of a predetermined area including the pixel, wherein the predetermined area for all pixels in the image is An image processing apparatus comprising: an expansion unit that expands a peripheral portion of the image so as to have a size that can be accommodated; and an execution unit that executes the image processing by using pixels in the predetermined region. 6. The expansion means expands the peripheral portion of the image so that the predetermined area for all the pixels in the image can be accommodated, and the pixel in the image is set as the value of the pixel of the expanded portion. The image processing apparatus according to claim 5, wherein a value of a pixel located closest to the pixel is used. 7. The image processing apparatus according to claim 1, wherein the image processing is a two-dimensional spatial filtering processing. 8. The image processing apparatus according to claim 1, wherein the image processing is smoothing processing. 9. An image processing method for performing image processing for determining a value of each pixel in an image based on a value of a pixel in a predetermined area including the pixel, the method comprising: A setting step of setting as an execution area, an extraction step of extracting pixels existing in the execution area among pixels existing in the predetermined area, and an extraction step for each pixel in the execution area An image processing method comprising: performing the image processing by using the generated pixels; 10. An image processing method for performing image processing for determining a value of each pixel in an image based on a value of a pixel in a predetermined area including the pixel, wherein an area for performing the image processing in the image is defined. A setting step of setting as an execution area, and a setting step of resetting the value of the pixel existing outside the execution area among the pixels existing in the predetermined area based on the value of the pixel existing in the execution area, An image processing method, comprising: performing the image processing on each pixel in the execution area by using all the pixels in the predetermined area. 11. In the setting step, among the pixels existing in the predetermined area, the value of a pixel existing outside the execution area is closest to the pixel existing in the predetermined area and within the execution area. The image processing method according to claim 10, wherein the setting is performed again based on the pixel value. 12. An image processing method for performing image processing for determining a value of each pixel in an image based on a value of a pixel in a predetermined area including the pixel, wherein a portion of the predetermined area protruding from the image is An image processing method comprising: a setting step of setting the remaining area obtained by removal as an execution area; and an execution step of executing the image processing by using pixels in the execution area. 13. An image processing method for performing image processing for determining a value of each pixel in an image based on a pixel value of a predetermined area including the pixel, wherein the predetermined area for all pixels in the image is An image processing method comprising: an expansion step of expanding the peripheral portion of the image so that the image can be accommodated; and an execution step of executing the image processing by using pixels in the predetermined area. 14. The expanding step expands a peripheral portion of the image so that the predetermined area for all pixels in the image is accommodated, and as a pixel value of the expanded portion,
The image processing method according to claim 13, wherein a value of a pixel located closest to the pixel among pixels in the image is used.