JP4209140B2 - Image processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus capable of performing smoothing processing in the same manner even when the pixel arrangement is symmetrical vertically and horizontally.
[0002]
[Prior art]
When performing the smoothing, a matrix of pixels around the target pixel (for example, 3 × 3 pixels centered on the target pixel) is extracted, and the black and white of the target pixel is determined based on the black and white arrangement of the matrix. Further, when performing not only smoothing but also resolution conversion, for example, when enlarging twice in the main scanning direction and the sub-scanning direction, respectively, it is 4 pixels, and when enlarging only in the main scanning direction or only in the sub-scanning direction, it is 2 pixels. , Each pixel of interest is converted.
[0003]
Conventionally, as shown in FIG. 5, for example, a register of 0 to 11 is provided for a 3 × 3 pixel matrix, and the register “8” is used when the main scanning direction and the sub-scanning direction are doubled. , “9”, “10”, “11” are selected in the order of pixel data, and when the pixel data is enlarged only in the sub-scanning direction, the pixel data is selected in the order of registers “8”, “10”, and the main scanning direction In the case of enlargement to only the pixel data, the pixel data is selected in the order of the registers “8” and “9”, and in the case of noise removal without enlargement, the pixel data of only the register “8” is selected.
[0004]
[Problems to be solved by the invention]
In the above conventional pixel conversion, as shown in FIGS. 6A and 6B, even when the image at the register time is symmetrical and has the same interpolation information, the output image is asymmetric at the time of sub-scan enlargement. Become. That is, black data is registered in the register “10” at the time of the register shown in FIG. 6A, and in the sub-scan enlargement, as shown in FIG. 5, the registers “8” and “10” are arranged in this order. Since it is selected, the output image has been subjected to smoothing processing. On the other hand, black data is registered in the register “11” at the time of FIG. 6B, but since the data in the register “11” is not adopted during sub-scanning enlargement, the output image is smoothed. Will not be given.
[0005]
Such a problem can occur not only in a left-right symmetric image but also in a vertically symmetric image. Therefore, even if the pixel arrangement pattern is bilaterally symmetric or vertically symmetric, there are cases where smoothing processing is not performed during sub-scanning enlargement.
[0006]
The present invention has been made paying attention to such problems, and provides an image processing apparatus capable of performing smoothing processing in the same manner even when the pixel arrangement is symmetrical vertically and horizontally. It is an object.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an image processing apparatus according to the present invention performs smoothing when the pixel of interest extracted from an image is subjected to resolution conversion twice in the main scanning direction and the sub scanning direction, the sub scanning direction, or the main scanning direction. When the processing is performed, the pixel extraction means for extracting the pixel of interest and the surrounding 3 × 3 pixel matrix around the pixel of interest and the resolution conversion based on the black and white arrangement of the extracted 3 × 3 pixel matrix be those with a pixel data generating means for determining a black-and-white of the pixel of interest, the pixel data generating means, for pixels other than the target pixel of the 3 × 3 pixel matrix, corresponding to each pixel Each pixel has one register, and for the target pixel, when the resolution conversion is doubled in the main scanning direction and the sub-scanning direction, the target pixel is a total of two pixels in the main scanning direction and two pixels in the sub-scanning direction. There are four registers according to conversion to pixels, and when converting the resolution twice in the sub-scanning direction, there are two registers according to converting the pixel of interest into two pixels in the sub-scanning direction, When the resolution conversion is performed twice in the main scanning direction, there are two registers corresponding to the conversion of the pixel of interest into two pixels in the main scanning direction, and each register corresponds to the 3 × 3 pixel matrix. When the pixel data generation means converts the resolution of the pixel of interest twice in the main scanning direction and the sub-scanning direction, the pixel data generation unit stores four pixels of the four registers. The register data corresponding to the two pixels in the upper row is selected as the data of the upper two pixels in the four pixels of the pixel of interest after resolution conversion as it is, and the register data corresponding to the lower two pixels in the four pixels is selected. If the data is selected as data of two pixels in the lower row of the four pixels of the pixel of interest after resolution conversion and the pixel of interest is subjected to resolution conversion twice in the sub-scanning direction, the register data corresponding to the two pixels is selected. Are selected as the data of the two pixels of the pixel of interest after resolution conversion, and when the pixel of interest is subjected to resolution conversion twice in the main scanning direction, the register data corresponding to the two pixels is directly subjected to resolution conversion. The selection is made as data of two pixels of the target pixel .
[0008]
Since this image processing apparatus has the above-described configuration, smoothing processing is similarly performed after resolution conversion even if the surrounding 3 × 3 pixel matrix centered on the pixel of interest is a pixel array that is symmetrical vertically or horizontally. Can do.
[0009]
Further, in the above configuration, the pixel data generation unit has one register for the target pixel when the resolution conversion is not performed for the target pixel, and the register includes black data of the target pixel in the 3 × 3 pixel matrix or When white data is stored and the pixel data generation means does not convert the resolution of the pixel of interest, the data of the register may be selected as data of the pixel of interest that does not perform resolution conversion as it is.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to embodiments. However, the present invention is characterized in that pixel data that has been subjected to smoothing and resolution conversion is generated based on surrounding pixel data, and this point will be mainly described.
[0011]
A circuit diagram of a main part of the image processing apparatus according to the embodiment is shown in FIG. Here, it is assumed that a 3 × 3 pixel matrix around the target pixel is extracted when smoothing is performed. Corresponding to each pixel, there are storage cells “0”, “1”, “2”, “3”, “4”, “5”, “6”, “7”, “X” of the register 4; Video signals (decoded image data) are sequentially input to the line memories 1, 2, 3, and the data in the line memory 1 are stored in the storage cells “0”, “7”, “6” of the register 4 a in the line memory 2. The data is sequentially input to the storage cells “1”, “X”, and “5” of the register 4b, and the data of the line memory 3 is sequentially input to the storage cells “2”, “3”, and “4” of the register 4c.
[0012]
Pixel data for resolution conversion in the main scanning direction and sub-scanning direction, pixel data for resolution conversion in the main scanning direction, pixel data for resolution conversion in the sub-scanning direction, pixels for noise removal without enlargement A circuit diagram for generating each data is as shown in FIG.
[0013]
In FIG. 2, at the time of enlarging in the main scanning direction and the sub-scanning direction, the stored contents of the target pixel X are input to the thumb switch 13, and the stored contents of the storage cells “8” and “9” are further input to the pixel switch 10. The storage contents of the memory cells “10” and “11” are input to the pixel switch 11, and the outputs of the pixel switches 10 and 11 are input to the thumb switch 13 via the line switch 12.
[0014]
When enlarging in the main scanning direction and the sub-scanning direction, first, in a state where the line switch 12 is turned on in the upper row of the target pixel, the contents of the memory cells “8” and “9” Then, the signals are sequentially selected and output to the thumb switch 13. Next, when the scanning shifts to the lower row of the target pixel and the line switch 12 is turned on to the lower row, the contents of the memory cells “10” and “11” are sequentially selected and output to the thumb switch 13 via the pixel switch 11 and the line switch 12. Is done.
[0015]
At the time of enlargement in the sub-scanning direction, the stored contents of the pixel of interest X are input to the sum switch 13, the stored contents of the storage cells "12" and "13" are input to the line switch 12, and the output of the line switch 12 is the sum switch. 13 is input. In this case, the content of the memory cell “12” is output to the thumb switch 13 via the line switch 12 in a state where the line switch 12 is turned on in the upper line in the target pixel, and then the line switch 12 is output in the target pixel. When turned on in the lower row, the contents of the memory cell “13” are selectively output from the line switch 12 to the thumb switch 13.
[0016]
At the time of enlargement in the main scanning direction, the stored contents of the target pixel X are input to the thumb switch 13, the stored contents of the storage cells "14" and "15" are input to the pixel switch 10, and the output of the pixel switch 10 is the sum switch. 13 is input. In this case, the contents of the memory cells “14” and “15” are sequentially selected and output to the thumb switch 13 via the pixel switch 10.
[0017]
When there is no enlargement, the stored contents of the pixel of interest X are input to the thumb switch 13 and the stored contents of the memory cell “16” are directly input to the thumb switch 13.
[0018]
Next, the operation of the pixel data generation circuit configured as described above will be described. In this pixel data generation circuit, as shown in FIG. 3, there is a register having 0 to 16 memory cells (hereinafter, each memory cell is simply referred to as a register) for a 3 × 3 pixel matrix. When enlarging both the direction and the sub-scanning direction twice, the registers “8”, “9”, “10”, and “11” are selected in this order. When enlarging only in the sub-scanning direction, the register “ When selecting 12 ”and“ 13 ”in this order and enlarging only in the main scanning direction, select in the order of registers“ 14 ”and“ 15 ”. When removing noise without enlargement, register“ 16 ” Only have selected.
[0019]
In this pixel conversion, as shown in FIGS. 4A and 4B, when the image at the register point is symmetrical and has the same interpolation information, the sub-scan enlargement register “12” is used in the sub-scan enlargement. Since the data is taken from “,” “13”, the output image is also symmetrical. That is, at the time of the register shown in FIG. 4A, black data is registered in the register “13” at the time of sub-scan enlargement, and the register “13” is selected as it is, so that the output image is subjected to smoothing processing. Will be. Also, at the time of FIG. 4B, the same register “13” is employed, so that the output image has been subjected to smoothing processing.
[0020]
Of course, the smoothing process is similarly performed in the case of a vertically symmetrical image. Therefore, smoothing processing is performed even for a pixel arrangement pattern that is symmetrical or vertically symmetrical.
[0021]
【The invention's effect】
As described above , according to the image processing apparatus according to claim 1 of the present invention, since it has the above-described configuration, the surrounding 3 × 3 pixel matrix centered on the pixel of interest has a pixel arrangement that is symmetrical vertically and horizontally. Even in such a case, the smoothing process can be performed in the same manner after the resolution conversion .
[0022]
Further, with the configuration according to claim 2, it is possible to determine the data of the pixel of interest when the resolution is not converted.
[Brief description of the drawings]
FIG. 1 is a circuit diagram illustrating a main part of an image processing apparatus according to an embodiment.
FIG. 2 illustrates pixel data for resolution conversion in the main scanning direction and sub-scanning direction, pixel data for resolution conversion in the main scanning direction, pixel data for resolution conversion in the sub-scanning direction in the image processing apparatus; It is a circuit diagram which each produces | generates the pixel data for the noise removal at the time of no expansion.
FIG. 3 is a diagram showing each storage cell of a register for a 3 × 3 pixel matrix;
FIG. 4 is a diagram illustrating an image stored in a register, an input image, and an output image in the case of a symmetric image.
FIG. 5 is a diagram showing each storage cell of a register for a 3 × 3 pixel matrix according to a conventional example.
FIG. 6 is a diagram showing a stored image, an input image, and an output image of a register in the case of a symmetric image according to a conventional example.
[Explanation of symbols]
1-3 Line memory 4 Register 10, 11 Pixel switch 12 Line switch 13 Thumb switch

Claims (2)

When performing a smoothing process when the resolution of the pixel of interest extracted from the image is doubled in the main scanning direction and the sub-scanning direction, the sub-scanning direction, or the main scanning direction, the pixel of interest and the pixel of interest are centered. Pixel extraction means for extracting the surrounding 3 × 3 pixel matrix, and pixel data generation means for determining the black and white of the pixel of interest after resolution conversion based on the black and white arrangement of the extracted 3 × 3 pixel matrix an image processing apparatus,
The pixel data generation unit has one register corresponding to each pixel for pixels other than the target pixel in the 3 × 3 pixel matrix, and the target pixel in the main scanning direction and the sub-scanning direction. When converting the resolution to 2 times, there are 4 registers to convert the pixel of interest into 2 pixels in the main scanning direction and 2 pixels in the sub scanning direction, and the resolution is doubled in the sub scanning direction. When converting, it has two registers according to the conversion of the target pixel into two pixels in the sub-scanning direction, and when converting the resolution twice in the main scanning direction, the target pixel is converted into two pixels in the main scanning direction. Have two registers to do,
Each register stores black data or white data of a corresponding pixel in the 3 × 3 pixel matrix,
When the pixel data generation unit performs resolution conversion of the pixel of interest twice in the main scanning direction and the sub-scanning direction, among the four registers, the register data corresponding to the two pixels in the upper row of the four pixels, The data is selected as the data of the upper two pixels in the four pixels of the target pixel after the resolution conversion as it is, and the register data corresponding to the lower two pixels of the four pixels is directly converted into the lower row of the four pixels of the target pixel after the resolution conversion. Selected as data of 2 pixels,
When the resolution of the target pixel is doubled in the sub-scanning direction, the register data corresponding to the two pixels is selected as data of the two pixels of the target pixel after the resolution conversion as it is,
When performing resolution conversion of a pixel of interest twice in the main scanning direction, the data of the register corresponding to the two pixels is selected as it is as data of two pixels of the pixel of interest after resolution conversion. . The pixel data generation means has one register for the target pixel when the resolution conversion is not performed for the target pixel, and the register stores black data or white data of the target pixel in the 3 × 3 pixel matrix. 2. The image processing apparatus according to claim 1 , wherein the pixel data generation unit selects the data of the register as the data of the pixel of interest that does not perform resolution conversion as it is when the pixel of interest does not perform resolution conversion .

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