JP2002300377A - Image data thinning out/interpolation device, image data thinning out/interpolation method, image data thinning out/interpolation program and computer-readable recording medium for recording the image data thinning out/interpolation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image data thinning out/interpolation device that interpolates color image data with high image quality at a high-speed. SOLUTION: (1) An original image recorded on an HDD is read under the instruction from a CPU1, (2) and the CPU1 reads an image on a RAM1 and compresses the image. (3) The CPU1 writes the compressed data to other areas of the RAM1. (4) A RAM2 in a printer records the compressed data under the instruction of the CPU1. (5) A CPU2 in the printer reads the compressed data to obtain a decoded value and to expand the image. (6) The CPU2 writes data after expansion to the RAM2. (7) Then the printer prints out the expanded data by a prescribed procedure of 'applying variable power'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image data thinning / interpolating apparatus for thinning / interpolating color image data, an image data thinning / interpolating method, and an image data thinning / interpolating method.
The present invention relates to an interpolation program and a computer-readable recording medium that records an image data thinning / interpolation program.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Unexamined Patent Application Publication No.
It is known that a thinning method is used at the time of compression and interpolation is performed by a single method at the time of decompression, as described in “Method and Apparatus for Thinning out Color Image Data and Method for Compressing Color Image Data” described in Japanese Unexamined Patent Publication (Kokai) No. H10-26095.

However, when the degree of thinning is large and the area to be interpolated is wide, the image quality is deteriorated by the interpolation using a single method. Also, in order to maintain the image quality after interpolation, it is necessary to devise thinning.

Accordingly, in the present application, when thinning out, the thinning position of three components is changed, and a plurality of interpolation methods (for example, 3 methods described in "Introduction to Computer Image Processing").
And two interpolation methods (nearest neighbor method, linear interpolation method, and cubic interpolation method).

[0005]

Here, the number of interpolation methods to be used and the combination of the interpolation methods are to improve the accuracy in the order of the luminance component and the color difference component. It is also desirable to change the accuracy between the color difference components.

For example, when the color conversion is RCT, R = U
+ G, G = Y-((U + V) / 4 (, B = V + G. This is because if the UUV value after quantization is subjected to the YUV inverse transform, the decoded R ' Although the value of G'B 'is obtained, an error naturally occurs between the value of the original RGB and the value of R'G'B', and such an error causes a color error (for example, in a known Lab space) by an observer. Color difference, hereinafter referred to as Lab color difference).

[0007] When the degree of quantization is small, the resulting color error is small and the observer often cannot perceive it.
However, when it is desired to increase the degree of quantization (compression ratio), the color error reaches a perceptible level, so that the accuracy is changed by the color differences U and V. By selecting an interpolation method that matches the characteristics of these three components, high-speed and high-quality color image data interpolation can be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above-described problems, and has an image data thinning / interpolating apparatus capable of performing high-speed and high-quality color image data interpolation, an image data thinning / interpolating method, and image data. It is an object of the present invention to provide a computer-readable recording medium on which a thinning / interpolation program and image data thinning / interpolation program are recorded.

[0009]

According to a first aspect of the present invention, there is provided an apparatus for thinning image data, comprising the steps of:
The interpolation device uses the thinned color image data,
An image data decimation / interpolation device for interpolating data of an original pixel group, wherein a luminance component is interpolated by two or more interpolation methods,
It is characterized in that the two color difference components are interpolated by the following method of the type of the interpolation method of the luminance component.

According to a second aspect of the present invention, there is provided an image data thinning / interpolating apparatus for interpolating original pixel group data using thinned color image data. The luminance component and one chrominance component are interpolated by two or more interpolation methods, and the other chrominance component is interpolated by a method equal to or less than the type of interpolation method between the luminance component and one chrominance component.

According to a third aspect of the present invention, in the image data thinning / interpolating apparatus, the luminance component is interpolated by two interpolation methods, and the two color difference components are interpolated by one method. .

According to a fourth aspect of the present invention, in the image data thinning / interpolating apparatus, the luminance component is interpolated by two interpolation methods, one color difference component is interpolated by one interpolation method, and the other color difference component is interpolated by another interpolation method. The color difference component is interpolated by an interpolation method different from the interpolation method applied to one color difference component.

According to a fifth aspect of the present invention, in the image data thinning / interpolating apparatus, the luminance component and one color difference component are interpolated by two interpolation methods, and the other interpolation method is one interpolation method. It is characterized by interpolation.

According to a sixth aspect of the present invention, there is provided an image data thinning / interpolating apparatus for thinning out data of an original pixel group for color image data, the image data thinning / interpolating apparatus comprising a luminance component and two color differences. In the component, there is no pixel in which each pixel group in the thinning range overlaps.

According to a seventh aspect of the present invention, there is provided an image data thinning / interpolating apparatus for thinning out data of an original pixel group for color image data, the image data thinning / interpolating apparatus comprising a luminance component and one color difference. In the component and the other color difference component, there is no pixel in which the pixel groups in the respective thinning ranges overlap.

An image data thinning / interpolating apparatus according to the invention of claim 8 is an image data thinning / interpolating apparatus for thinning out data of an original pixel group for color image data, wherein a luminance component and two color difference In the components, the number of pixel groups in each thinning range is minimized.

According to a ninth aspect of the present invention, there is provided an image data thinning / interpolating apparatus for thinning out data of an original pixel group for color image data, the image data thinning / interpolating apparatus comprising a luminance component and one color difference. In the component and the other color difference component, the number of pixels in the range to be thinned out is minimized.

According to a tenth aspect of the present invention, there is provided an image data thinning / interpolating apparatus for thinning out data of an original pixel group for color image data. It is characterized in that the pixel groups in the range in which the color difference components are thinned out are of the dot dispersion type.

An image data thinning / interpolating apparatus according to the present invention is characterized in that the luminance component and the two color difference components are respectively restored by a nearest neighbor method.

According to a twelfth aspect of the present invention, there is provided the image data thinning / interpolating apparatus according to any one of the sixth to ninth aspects, wherein a pixel group in a thinning range of a luminance component is provided. The method is characterized in that pixels adjacent to a pixel group in a thinning range in one color difference component are restored by a nearest neighbor method.

According to a thirteenth aspect of the present invention, there is provided the image data thinning / interpolating apparatus, wherein pixels other than those of the nearest neighbor method are restored by a linear interpolation method.

An image data thinning-out / interpolating apparatus according to the invention of claim 14 is characterized in that pixels other than the ones restored by the nearest neighbor method are restored by a cubic interpolation method.

According to a fifteenth aspect of the present invention, in the image data thinning / interpolating apparatus, two or one color difference components are restored by the nearest neighbor method.

According to a sixteenth aspect of the present invention, the image data thinning-out / interpolating apparatus restores one color difference component by the nearest neighbor method and restores another color difference component by the cubic interpolation method. Features.

According to a seventeenth aspect of the present invention, in the image data thinning / interpolating apparatus, the first pixel group in the luminance component is Xy × Yy pixels, and the second pixel group is m × n pixels. Xu ×
It is characterized in that the Yu pixel, the fourth pixel group are mu × nu pixels, the fifth pixel group in the other color difference component is Xv × Yv pixels, and the sixth pixel group is mv × nv pixels.

The image data thinning-out / interpolating apparatus according to the eighteenth aspect of the present invention provides the image data thinning / interpolating apparatus, wherein
y, wherein Yy is m−Xy ≧ 3, n−Yy ≧ 3 or 2x <m, 2y <n.

The image data thinning / interpolating method according to the present invention is an apparatus for interpolating original pixel group data for thinned color image data, wherein the luminance component has two or more luminance components. , Wherein the two color difference components are equal to or less than the number of luminance component interpolation methods.

According to a twentieth aspect of the present invention, there is provided an image data thinning / interpolating method for thinning out data of an original pixel group for color image data, wherein a pixel group in a first range in a luminance component is selected. It is characterized in that there are no pixels overlapping the third and fifth pixel groups in the two color difference components.

According to a twenty-first aspect of the present invention, there is provided an image data thinning / interpolating apparatus for thinning out data of an original pixel group for color image data, wherein a pixel group in a first range in a luminance component is extracted. A feature is that the number of overlapping pixels of the third and fifth pixel groups in the two color difference components is minimized.

An image data thinning / interpolating method according to the invention of claim 22 is an apparatus for thinning out data of an original pixel group for color image data, wherein a first component of a luminance component, a color difference component, and a color difference component is provided. , 3, and 5 are of a dot dispersion type.

According to a twenty-third aspect of the present invention, an image data decimation / interpolation program causes a computer to realize the functions of the image data decimation / interpolation device according to the first to eighteenth aspects.

[0032] A computer-readable recording medium according to a twenty-fourth aspect of the present invention is characterized by recording the program according to the twenty-third aspect.

According to a twenty-fifth aspect of the present invention, an image data thinning / interpolating program causes a computer to realize the functions of the image data thinning / interpolating method according to the nineteenth to twenty-second aspects.

According to a twenty-sixth aspect of the present invention, a computer-readable recording medium has recorded thereon the program according to the twenty-fifth aspect.

Thus, according to the first aspect of the present invention, there is provided an apparatus for interpolating data of an original pixel group using thinned color image data, wherein two or more luminance components are used. Since the interpolation method and the two color difference components are equal to or less than the number of the luminance component interpolation methods, high image quality can be achieved by increasing the number of the interpolation methods for the luminance component compared to the color difference components.

According to the second aspect of the present invention, there is provided an apparatus for interpolating data of an original pixel group using thinned color image data, wherein a luminance component and one color difference component are two. Since the above interpolation method and the other color difference component are equal to or less than the number of interpolation methods for the luminance component and one color difference component, by changing the number of interpolation methods according to the characteristics of each of the two color difference components, high image quality and can do.

According to the third aspect of the present invention, in the first aspect, the luminance component is interpolated by two interpolation methods.
Since the two color difference components are interpolated by one method, high speed and high image quality can be achieved as compared with the case where all three components are interpolated by the same method.

According to a fourth aspect of the present invention, in the first aspect, the luminance component is interpolated by two interpolation methods.
Since one color difference component is interpolated by one interpolation method and the other color difference component is interpolated by an interpolation method different from the interpolation method applied to one color difference component, two color difference components are restored by the same interpolation method. As compared with, an interpolation method suitable for the characteristics of each component can be selected, so that high image quality can be achieved.

According to a fifth aspect of the present invention, in the second aspect, the luminance component and one color difference component are interpolated by two interpolation methods, and the other interpolation method is interpolated by one interpolation method. Therefore, it is possible to achieve high speed and high image quality as compared with the case where the other color difference component is restored by one method.

According to the invention described in claim 6, there is provided an apparatus for thinning out data of an original pixel group for color image data, wherein a pixel group in a thinning-out range for each of a luminance component and two color difference components is provided. Since there are no overlapping pixels, 3
By having information over a wider range than having information at the same position for both components, it is possible to reduce the number of pixels that have no information at all and reduce image quality degradation due to interpolation.

According to the seventh aspect of the present invention, there is provided an apparatus for thinning out data of an original pixel group for color image data, wherein each of a luminance component, one color difference component, and another color difference component is provided. Since there is no overlapping pixel group in the thinning range, by holding information in a wider range compared to having two components of color difference at the same position, the number of pixels having no information is reduced, and image quality is reduced. Deterioration can be further reduced.

According to the eighth aspect of the present invention, there is provided an apparatus for thinning out data of an original pixel group for color image data, wherein a pixel group in a thinning range of each of a luminance component and two color difference components is provided. By minimizing the number of pixels that have no information at all, by reducing the number of pixels that have no information at all, by reducing the number of pixels that have no information at all, compared to having the information at the same position in all three components Can be.

According to the ninth aspect of the present invention, there is provided an apparatus for thinning out data of an original pixel group from color image data, wherein each of a luminance component, one color difference component, and another color difference component is provided. Since the number of pixels in the range to be thinned is minimized, the number of pixels having no information is reduced by providing information in a somewhat wide range as compared to having two components of color difference at the same position, Image quality deterioration can be further reduced.

According to the tenth aspect of the present invention,
For color image data, this is a device for thinning out the data of the original pixel group, and since the pixel groups in the range in which the luminance component, the color difference component, and the color difference component are thinned out are each of the dot dispersion type, the number of pixels having no information at all is determined. By ideally dispersing, high image quality can be obtained.

According to the eleventh aspect of the present invention,
In the tenth aspect, since the luminance component and the two color difference components are respectively restored by the nearest neighbor method, it is possible to maintain a high speed to some extent by using only the nearest neighbor method for the luminance component.

According to the twelfth aspect of the present invention,
In the sixth to ninth aspects, a pixel group in a thinning range in a luminance component is restored. In the seventh and ninth aspects, a pixel adjacent to a pixel group in a thinning range in one color difference component is restored by a nearest neighbor method. Although the number of pixels to be restored is small, the speed is reduced, but the image quality can be maintained to a certain extent without jaggies being noticeable.

According to the thirteenth aspect of the present invention,
In the twelfth aspect, since pixels other than those restored by the nearest neighbor method are restored by the linear interpolation method, a certain speed is maintained as compared with restoring all the luminance Y component or color difference V component by the nearest neighbor method. While maintaining the image quality.

According to the fourteenth aspect of the present invention,
In the twelfth aspect, since pixels other than those restored by the nearest neighbor method are restored by the cubic interpolation method, the image quality can be improved although the speed is lower than that of the pixel restored by the linear interpolation method.

According to the fifteenth aspect of the present invention,
Since the two or one color difference components are restored by the nearest neighbor method, the speed can be maintained by restoring all the two or one color difference components by the nearest neighbor method.

According to the sixteenth aspect of the present invention,
10. The method according to claim 7, wherein one of the color difference components is restored by the nearest neighbor method and the other color difference component is restored by the cubic interpolation method. But the image quality can be improved.

According to the seventeenth aspect of the present invention,
In Claims 13 and 14, the first pixel group in the luminance component is Xy × Yy pixels, the second pixel group is m × n pixels, and the third pixel group in one color difference component is Xu × Yu pixels. Since the fourth pixel group is mu × nu pixels, the fifth pixel group in the other color difference component is Xv × Yv pixels, and the sixth pixel group is mv × nv pixels,
Since it is a simple form, interpolation can be performed at high speed.

According to the eighteenth aspect of the present invention,
In claim 17, since m−Xy ≧ 3, n−Yy ≧ 3 or 2x <m, 2y <n, the effect of maintaining the high speed and maintaining the image quality by widening the pixel width can be maintained.

According to the nineteenth aspect of the present invention,
This is a proposal of the image interpolation method according to claim 1, wherein high-speed and high-quality images can be obtained as compared with the case where all three components are interpolated by the same method.

According to the twentieth aspect of the present invention,
7. An image compression method according to claim 6, wherein the three components have information in a wide range as compared with having information in the same range, so that the image quality degradation due to pixels having no information is reduced moderately. Can be done.

According to the twenty-first aspect of the present invention,
This is a proposal of the image compression method according to claim 8, in which information is provided in a wide range to some extent, so that image quality deterioration due to a pixel having no information can be reduced moderately.

According to the twenty-second aspect of the present invention,
This is a proposal of the image compression method according to claim 10, wherein the interpolation method can be simplified by making each component a dot dispersion type.

According to the twenty-third or twenty-fifth aspect of the present invention, a computer can realize each of the above functions.

According to the computer-readable recording medium of the invention according to claim 24 or 26, by recording a program for causing a computer to execute the above functions, the program can be read by a computer. Thus, the above operation can be realized by a computer.

[0059]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the accompanying drawings, an image data thinning / interpolating apparatus, an image data thinning / interpolating method, an image data thinning / interpolating program, and an image data thinning / interpolating program according to the present invention will be described below. A preferred embodiment of the computer-readable recording medium described above will be described in detail.

FIG. 14 shows an example of an apparatus configuration according to the present invention. HDD, RAM1 via data bus
(Within the PC), the CPU 1 (within the PC), and the printer are connected. When the original image is printed out, the data is compressed and the compressed data is transmitted to the printer. Since the amount of data to be transmitted to the printer is reduced, the transmission time is shortened, and high-speed printing is possible even in consideration of the time required for compression and decompression.

FIG. 1 and FIG. 2 show the contents of the present embodiment (Embodiment 1). FIG. 1 is a diagram showing thinning positions for color image data, and FIG. 2 is a diagram showing thinning positions for two color difference components. It is to be noted that, first, numerals shown in the drawings are indicated by numerals in parentheses for convenience of explanation. That is, (1) is set. The same applies to other numbers.

Here, there is no pixel overlapping the black portion of the luminance component and the two color difference components. This gives 3
By having information over a wider range than having both components in the same range, image quality degradation due to pixels having no information at all is reduced.

Here, each of the three components has 5 × 5 pixels as one unit. Referring to FIG. 1, when generating 5 × 5 pixels from 2 × 2 pixels which are black portions, interpolation other than the black portions is performed by one or more methods.

Referring to FIG. 2, the black portion 2 ×
When generating 5 × 5 pixels from two pixels, interpolation is performed by one method. First, when a pixel adjacent to two sides of the black portion in FIG. 1 is set as a gray portion, the gray portion is interpolated by a certain method,
Interpolate the white part by another method.

The nearest neighbor method was used for gray parts, and the linear interpolation method was used for white parts. The gray part is obtained by directly interpolating the data of the adjacent black part, and the white part is (9) = ((1) +
(2)) / 2, (10) = ((5) + (7)) / 2,
(11) = ((3) + (4)) / 2, (12) =
((5) + (6)) / 2, (13) = ((7) +
(8)) / 2, (14) = ((6) + (8)) / 2
Interpolation is performed as (15) = ((12) + (13)) / 2.

Next, the nearest neighbor method was used to restore the white portion of FIG. In this method, the white portion directly interpolates the data of the black portion. As a result, compared to restoring all the luminance components by the nearest neighbor method, while maintaining the speed,
The image quality can be maintained to a certain extent without the jaggy being noticeable.

Here, when it is assumed that m × n pixels are generated from Xy × Yy pixels in the luminance component, m−Xy ≧ 3,
n−Yy ≧ 3 or 2x <m, 2y <n and X ≦ Xy,
When Y ≦ Yy, there is an effect by combining the interpolation methods. Therefore, FIG. 15 shows the flow of the above-described processing for the contents of the first embodiment.

FIGS. 3 and 4 show the contents of the first embodiment. FIG. 3 is a diagram showing the thinning positions of the color image data, and FIG. Here, the pixels overlapping the black portions of the luminance component and the two color difference components are minimized.

By providing information in a somewhat wide range as compared with having information at the same position for all three components, the number of pixels having no information is reduced, and image quality degradation is reduced moderately.

Here, 5 × 5 pixels are defined as one unit for all three components. Referring to FIG. 3, when generating 5 × 5 pixels from 3 × 3 pixels which are black portions, interpolation other than the black portions is performed by one or more methods. Referring to FIG. 4, when generating 5 × 5 pixels from 3 × 3 pixels which are black portions, interpolation is performed by one method.

First, when a pixel adjacent to two sides of the black portion in FIG. 3 is set as a gray portion, the gray portion is interpolated by the first method, and the white portion is interpolated by a method other than the first method. The nearest neighbor method was used for gray parts, and the linear interpolation method was used for white parts.

The gray part is obtained by directly interpolating the data of the adjacent black part, and the white part is (7) = ((1) +
(4)) / 2, (8) = ((2) + (5)) / 2
Interpolation is performed as (9) = ((3) + (6)) / 2.

Next, the nearest neighbor method was used to restore the white portion of FIG. In this method, the white portion directly interpolates the data of the black portion. As a result, as compared with the case where all the luminance Y components are restored by the nearest neighbor method, the speed is reduced, but the image quality can be maintained to a certain extent with less jaggies.

Here, when it is assumed that m × n pixels are generated from Xy × Yy pixels in the luminance component, m−Xy ≧ 3,
n−Yy ≧ 3 or 2x <m, 2y <n and X ≦ Xy,
When Y ≦ Yy, there is an effect by combining the interpolation methods.

FIG. 15 shows the flow of the above-described processing for the contents of the first embodiment.

FIGS. 5, 6, and 7 show examples of the invention according to the second embodiment. Regarding the color image data, FIG. 5 shows a luminance component, FIG. 6 shows one color difference component, and FIG. 7 shows a thinning position of another color difference component. Here, it is assumed that there is no pixel in which the black portions of all three components overlap.

As a result, by holding information in a wider range than when two components of color difference are held at the same position, the number of pixels having no information is reduced, and image quality deterioration is further reduced.

Here, 5 × 5 pixels are defined as one unit. FIG.
When generating 5 × 5 pixels from 2 × 2 pixels which are black portions, interpolation other than the black portions is performed by one or more methods. 6 and 7, the black portion 2
When generating 5 × 5 pixels from × 2 pixels, they are interpolated by different methods one by one.

When a pixel adjacent to two sides of the black portion in FIG. 5 is set as a gray portion, the gray portion is interpolated by the first method, and the white portion is interpolated by a method other than the first method. The nearest neighbor method is used for gray parts, and the cubic interpolation method is used for white parts.

That is, in the gray part, the data of the adjacent black part is directly interpolated. Also, (1) to (1)
6) are points G to V, and (17) is a point Z.
Using the 16 points G to V around the point Z, interpolation is made to (17) by the following equation.

F (Z) = f (G) C (xG-xZ) C (yG-
yZ) + f (H) C (xH-xZ) C (yH-yZ) + ‥‥ +
f (V) C (xV-xZ) C (yV-yZ)

C (t) = 1-2t2 + | t | 3 (0 ≦ | t | <1)

C (t) = 4-8 | t | + 5t2- | t | 3 (1 ≦ | t | <2)

C (t) = 0 (2 ≦ | t |)

Here, C (t) is an approximate expression of a function sinπx / πx constituting the sampling theorem.
Used for each of the components G and B. Since interpolation is performed using 16 points of information, the speed is lower than when linear interpolation is used, but blurring is reduced and high image quality is obtained. The predetermined value is determined by conditions such as the display capability of the display device and the observation distance, and the above values are merely examples.

Next, the nearest neighbor method was used to restore the white portion of FIG. In this method, the white portion directly interpolates the data of the black portion. In addition, a cubic interpolation method was used to restore the white portion in FIG.

This is interpolated as in FIG. As a result, the speed is considerably reduced as compared with the case where one of the color difference components is restored by the nearest neighbor method, but the image quality is high.

Here, when it is assumed that m × n pixels are generated from Xy × Yy pixels in the luminance component, m−Xy ≧ 3,
n−Yy ≧ 3 or 2x <m, 2y <n and X ≦ Xy,
When Y ≦ Yy, there is an effect by combining the interpolation methods.

FIG. 16 shows the flow of the above-mentioned processing in the example of the invention according to the second embodiment.

FIGS. 8, 9, and 10 show the contents of the third embodiment. FIG. 8 is a diagram illustrating the thinning position of the color image data, FIG. 9 is a diagram illustrating the thinning position of one color difference component, and FIG. Here, the black portions of the three components are arranged such that overlapping pixels are minimized.

By providing information in a wider range to some extent as compared to having two components of color difference at the same position, the number of pixels having no information is reduced, and image quality deterioration is further reduced.

Here, 5 × 5 pixels are defined as one unit. 8 and 10, 3 × 3 pixels, which are black portions, are converted to 5 ×
When generating five pixels, interpolation other than the black part is performed by one or more methods. Referring to FIG. 9, when generating 5 × 5 pixels from 3 × 3 pixels which are black portions, interpolation is performed one by one using a different method.

First, when a pixel adjacent to two sides of the black portion in FIGS. 8 and 10 is set as a gray portion, the gray portion is interpolated by a certain method and the white portion is interpolated by another method. The nearest neighbor method was used for the gray part, and the linear interpolation was used for the white part.

In the gray part, the data of the adjacent black part is directly interpolated, and in the white part, (7) = ((1) +
(4)) / 2, (8) = ((2) + (5)) / 2
Interpolation is performed as (9) = ((3) + (6)) / 2.

Next, the nearest neighbor method was used to restore the white portion of FIG. In this method, the white portion directly interpolates the data of the black portion. As a result, although the speed is slightly reduced as compared with the case where the color difference V component is obtained only by the nearest neighbor method, jaggies become less noticeable and the image quality is improved to some extent.

FIG. 17 shows the flow of the above-mentioned processing in the example of the invention according to the third embodiment.

FIGS. 11, 12, and 13 show the contents of the fourth embodiment. FIG. 1 shows color image data.
1 is a luminance component, FIG. 12 is a diagram of one color difference component, and FIG. 13 is a diagram of a thinning position of another color difference component. The three components are of a dot dispersion type as shown in FIGS.

Thus, by ideally dispersing the number of pixels having no information at all, high image quality can be achieved, and all three components are restored by the nearest neighbor method. here,
For the white part, the data of the black part is directly interpolated. This is to increase the speed by using the nearest neighbor method for the luminance component.

FIG. 18 shows the flow of the above processing for the contents of the fourth embodiment.

FIG. 14 shows an example of an apparatus configuration according to the present invention. HDD, R via data bus
AM1 (in PC), CPU1 (in PC), and printer are connected. When the original image is printed out, the data is compressed and the compressed data is transmitted to the printer. Since the amount of data to be transmitted to the printer is reduced, the transmission time is shortened, and high-speed printing is possible even in consideration of the time required for compression and decompression.

The original image recorded on the HDD is read into the RAM according to a command from the CPU.

The CPU 1 reads an image on the RAM 1 and performs compression.

The CPU 1 stores the compressed data in the RAM 1
Write to another area above.

The data after compression is recorded on the RAM 2 in the printer in accordance with an instruction from the CPU 1.

The CPU 2 in the printer reads the compressed data, obtains a decoded value, and expands the image.

The CPU 2 stores the expanded data in the RAM 2
Write on top.

Thereafter, the printer prints out the decompressed data according to a predetermined procedure [magnification is applied].

As described above, according to the present embodiment, there is provided an apparatus for interpolating data of an original pixel group using thinned color image data. Since the two color difference components are equal to or less than the number of luminance component interpolation methods, high image quality can be achieved by increasing the number of interpolation methods for the luminance components compared to the color difference components.

Further, according to the present embodiment, there is provided an apparatus for interpolating data of an original pixel group using thinned color image data, wherein a luminance component and one color difference component are two or more interpolation components. Method, the other color difference component is equal to or less than the number of interpolation methods for the luminance component and one color difference component, so that high image quality can be obtained by changing the number of interpolation methods according to the characteristics of each of the two color difference components. it can.

Further, according to the present embodiment, the luminance component is interpolated by two interpolation methods, and the two chrominance components are interpolated by one method, so that all three components are interpolated by the same method. , High speed and high image quality.

According to the present embodiment, the luminance component is interpolated by two interpolation methods, one color difference component is interpolated by one interpolation method, and the other color difference component is applied to one color difference component. Since interpolation is performed using an interpolation method different from the interpolation method,
Compared to reconstructing two color difference components using the same interpolation method,
Since an interpolation method suitable for the characteristics of each component can be selected, high image quality can be achieved.

According to the present embodiment, the luminance component and one color difference component are interpolated by two interpolation methods, and the other interpolation method is interpolated by one interpolation method. Higher speed and higher image quality can be achieved as compared with the case where restoration is performed by one method.

Further, according to the present embodiment, an apparatus for thinning out the data of the original pixel group from the color image data is provided. Since there is no information, it is possible to reduce the number of pixels having no information at all and to reduce the image quality deterioration due to interpolation by having information in a wider range than when all three components have information at the same position.

Further, according to the present embodiment, an apparatus for thinning out the data of the original pixel group from the color image data, wherein the luminance component, the one color difference component and the other color difference component have the respective thinning ranges Since there is no overlapping pixel group, having two pieces of color difference information in the same position and having information over a wider range reduces the number of pixels that have no information at all and reduces image quality degradation. Can be reduced.

Further, according to the present embodiment, an apparatus for thinning out the data of the original pixel group from the color image data, wherein the number of pixels in the thinning-out range of each of the luminance component and the two color difference components is minimized. Therefore, by providing information in a somewhat wider range than when all three components have information at the same position, the number of pixels having no information can be reduced, and image quality degradation can be reduced moderately.

Further, according to the present embodiment, an apparatus for thinning out the data of the original pixel group from the color image data, wherein the luminance component, one of the color difference components and the other color difference component has the respective thinning ranges. Since the number of pixels is minimized, the number of pixels that have no information is reduced by providing information in a somewhat wider range than when two components of color difference are stored in the same position, thereby further deteriorating image quality. Can be reduced.

Further, according to the present embodiment, an apparatus for thinning out the data of the original pixel group from the color image data, wherein each of the pixel groups in the range in which the luminance component, the color difference component and the color difference component are thinned out is of a dot dispersion type. Since there is an ideal number of pixels having no information at all, high image quality can be achieved.

Further, according to the present embodiment, since the luminance component and the two color difference components are respectively restored by the nearest neighbor method, it is possible to maintain a high speed to some extent by using only the nearest neighbor method for the luminance component.

Further, according to the present embodiment, pixels adjacent to a pixel group in a thinning range of a luminance component and pixels adjacent to a pixel group in a thinning range of one color difference component are restored by a nearest neighbor method. Although the number of pixels is small, the speed is reduced, but the image quality can be maintained to some extent without jaggies being noticeable.

According to the present embodiment, pixels other than those restored by the nearest neighbor method are restored by the linear interpolation method.
Compared with the case where all of the luminance Y component or the color difference V component is restored by the nearest neighbor method, the image quality can be maintained while maintaining a certain speed.

According to the present embodiment, pixels other than those restored by the nearest neighbor method are restored by the cubic interpolation method.
The image quality can be improved though the speed is reduced as compared with the case where restoration is performed by the linear interpolation method.

Further, according to the present embodiment, since two or one of the color difference components is restored by the nearest neighbor method, the speed is maintained by restoring all the two or one color difference components by the nearest neighbor method. Can be.

According to the present embodiment, one of the chrominance components is restored by the nearest neighbor method, and the other chrominance component is restored by the cubic interpolation method. Although the speed is lower than that of the restoration, the image quality can be improved.

According to the present embodiment, the first pixel group in the luminance component is Xy × Yy pixels, the second pixel group is m × n pixels, and the third pixel group in one color difference component is Xu × Yu pixels, the fourth pixel group is mu × nu pixels, the fifth pixel group in the other color difference component is Xv × Yv pixels, and the sixth pixel group is mv × nv pixels. By doing so, interpolation can be performed at high speed because of the simple form.

According to the present embodiment, m−Xy ≧
Since 3, n−Yy ≧ 3 or 2x <m, 2y <n, it is possible to maintain the effect of maintaining the image quality at high speed by widening the pixel width.

Further, the image data thinning / interpolating method may be a computer-readable program prepared in advance, and is realized by executing the program on a computer such as a personal computer or a workstation. This program is recorded on a computer-readable recording medium such as an HD (hard disk), FD (floppy (registered trademark) disk), CD-ROM, MO, or DVD, and is executed by being read from the recording medium by the computer. You. Further, the program may be a transmission medium that can be distributed via a network such as the Internet.

[0127]

As described above, the apparatus according to the first aspect has an effect that high image quality can be obtained by increasing the number of interpolation methods for the luminance component and the color difference component.

Further, in the device according to the second aspect,
By changing the number of interpolation methods depending on the characteristics of each of the two color difference components, there is an effect that high image quality can be achieved.

Further, in the device according to the third aspect,
As compared with the case where all three components are interpolated by the same method, there is an effect that high speed and high image quality can be achieved.

Further, in the device according to the fourth aspect,
Compared to reconstructing two color difference components using the same interpolation method,
By selecting an interpolation method suitable for the characteristics of each component, there is an effect that high image quality can be achieved.

In the apparatus according to the fifth aspect,
As compared with the case where the other color difference component is restored by one method, an effect that high speed and high image quality can be obtained is achieved.

In the apparatus according to the sixth aspect,
By having information in a wider range than when all three components have information at the same position, it is possible to reduce the number of pixels having no information at all and to reduce the deterioration of image quality due to interpolation.

In the apparatus according to the seventh aspect,
By having information over a wider range than having two components of color difference at the same position, it is possible to reduce the number of pixels having no information at all and to reduce image quality deterioration. .

In the apparatus according to the eighth aspect,
By providing information in a somewhat wider range as compared to having information at the same position for all three components, the number of pixels having no information can be reduced and the image quality degradation can be reduced moderately. .

Further, in the device according to the ninth aspect,
By providing information in a wider range to some extent than having two components of color difference at the same position, the effect of reducing the number of pixels having no information at all and reducing image quality deterioration can be reduced. Play.

Further, in the device according to the tenth aspect, by dispersing the number of pixels having no information at all ideally, there is an effect that high image quality can be obtained.

In the apparatus according to the eleventh aspect, the use of only the nearest neighbor method for the luminance component has an effect that a high speed can be maintained to some extent.

Further, in the device according to the twelfth aspect, although the speed is reduced due to a small number of pixels restored by the nearest neighbor method, the effect that jaggies are not so noticeable and the image quality can be maintained to some extent.

Further, in the apparatus according to the thirteenth aspect, it is possible to maintain the image quality while maintaining a certain speed as compared with the case where all the luminance components or the color difference components are restored by the nearest neighbor method.

The apparatus according to the fourteenth aspect has the effect that the image quality is improved although the speed is reduced as compared with the case where the image is restored by the linear interpolation method.

The apparatus according to the fifteenth aspect has an effect that the speed can be maintained by restoring all two or one color difference components by the nearest neighbor method.

Further, in the apparatus according to the sixteenth aspect, although the speed is reduced as compared with the case where all the color difference components are restored by the nearest neighbor method, there is an effect that high image quality can be obtained.

Further, in the device according to the seventeenth aspect, the rectangular shape has an effect that interpolation can be performed at high speed because of a simple form.

In the device according to the eighteenth aspect, the effect of maintaining the high speed and maintaining the image quality can be maintained by widening the width of the pixel.

The method according to claim 19 is a proposal of the image interpolation method according to claim 1, which achieves higher speed and higher image quality as compared with the case where all three components are interpolated by the same method. This has the effect that it can be performed.

Further, the method according to claim 20 is a proposal of the image compression method according to claim 6, wherein information is provided in a wide range so that image quality deterioration due to a pixel having no information is prevented. This has the effect of being able to be reduced.

Further, the method according to claim 21 is a proposal of the image compression method according to claim 8, wherein the image is degraded by a pixel having no information by providing information in a certain wide range. Can be reduced.

Further, the method according to claim 22 is a proposal of the image compression method according to claim 9, wherein the interpolation method can be simplified by making each component a dot dispersion type. To play.

Further, in claim 23 or 25,
There is an effect that the above functions can be realized by a computer.

According to the computer-readable recording medium of the invention according to claim 24 or 26, by recording a program for causing a computer to execute the above functions, the program can be read by a computer. Accordingly, an effect is obtained that the above operation can be realized by a computer.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing contents of an image data thinning / interpolating apparatus according to an embodiment of the present invention;

FIG. 2 is an explanatory diagram showing another content of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 3 is an explanatory diagram showing another content of the image data thinning / interpolating device according to the embodiment of the present invention;

FIG. 4 is an explanatory diagram showing another content of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 5 is an explanatory diagram showing another content of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 6 is an explanatory diagram showing another content of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 7 is an explanatory diagram showing another content of the image data thinning / interpolating device according to the embodiment of the present invention;

FIG. 8 is an explanatory diagram showing another content of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 9 is an explanatory diagram showing another content of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 10 is an explanatory diagram showing another content of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 11 is an explanatory diagram showing another content of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 12 is an explanatory diagram showing another content of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 13 is an explanatory diagram showing another content of the image data thinning / interpolating device according to the embodiment of the present invention;

FIG. 14 is an explanatory diagram showing a configuration example of an image data thinning / interpolating device according to the embodiment of the present invention;

FIG. 15 is a flowchart illustrating a flow of processing of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 16 is a flowchart showing another processing flow of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 17 is a flowchart showing another processing flow of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

FIG. 18 is a flowchart showing another processing flow of the image data thinning / interpolating apparatus according to the embodiment of the present invention;

Continued on the front page F-term (reference) 5B057 CA01 CA08 CA16 CB01 CB08 CB16 CC02 CD06 CD07 CH01 CH11 CH14 5C076 AA21 AA22 BA06 BB04 BB06 BB15 BB24 BB40 5C077 LL19 MP08 NP05 PP20 PP28 PP36 PQ12 PQ22 LA17B02 LA0211 PA03

Claims (26)

[Claims] An image data thinning-out / interpolating apparatus for interpolating data of an original pixel group using thinned color image data, wherein a luminance component is interpolated by two or more interpolation methods, An image data decimation / interpolation apparatus characterized in that the components are interpolated by the following methods. 2. An image data decimation / interpolation device for interpolating data of an original pixel group using thinned color image data, wherein a luminance component and one color difference component are interpolated by two or more interpolation methods. An image data decimation / interpolation apparatus characterized in that the other chrominance component is interpolated by the following method of the type of interpolation between the luminance component and one chrominance component. 3. The apparatus according to claim 1, wherein the luminance component is interpolated by two interpolation methods, and the two color difference components are interpolated by one method. 4. An interpolation method different from the interpolation method applied to one color difference component, wherein the luminance component is interpolated by two interpolation methods, one color difference component is interpolated by one interpolation method. 2. The image data thinning / interpolating apparatus according to claim 1, wherein interpolation is performed by: 5. The method according to claim 2, wherein the luminance component and one color difference component are interpolated by two interpolation methods, and the other interpolation method is interpolated by one interpolation method. Interpolator. 6. An image data thinning-out / interpolation apparatus for thinning out data of an original pixel group for color image data, wherein in a luminance component and two color difference components, there is no pixel in which a pixel group in each thinning-out range overlaps. Characteristic image data thinning / interpolation device. 7. An image data thinning-out / interpolating apparatus for thinning out data of an original pixel group for color image data, wherein a pixel group in a thinning-out range of each of a luminance component, one color difference component, and another color difference component is obtained. An image data decimation / interpolation device characterized by having no overlapping pixels. 8. An image data thinning-out / interpolating apparatus for thinning out data of an original pixel group with respect to color image data, wherein a pixel group in a thinning-out range of each of a luminance component and two color difference components is minimized. Characteristic image data thinning / interpolation device. 9. An image data thinning-out / interpolating apparatus for thinning out data of an original pixel group for color image data, wherein a pixel group in a thinning-out range of each of a luminance component, one color difference component and another color difference component is provided. An image decimation / interpolation device characterized in that it is minimized. 10. An image data thinning-out / interpolating apparatus for thinning out data of an original pixel group with respect to color image data, wherein a pixel group in a range where a luminance component, a color difference component, and a color difference component are thinned out is a dot dispersion type. Characteristic image data thinning / interpolation device. 11. The apparatus according to claim 10, wherein the luminance component and the two chrominance components are respectively restored by a nearest neighbor method. 12. A pixel group in a range to be thinned out in a luminance component according to any one of claims 6 to 9, or a pixel adjacent to a pixel group in a range to be thinned out in one of the color difference components according to claim 7 or 9. An image data decimation / interpolation device characterized by restoration by a method. 13. The method according to claim 12, further comprising restoring pixels other than the nearest neighbor method using a linear interpolation method.
2. The image data thinning / interpolating device according to 1. 14. The method according to claim 12, wherein pixels other than the pixels restored by the nearest neighbor method are restored by a cubic interpolation method.
2. The image data thinning / interpolating device according to 1. 15. The apparatus for thinning out and interpolating image data according to claim 6, wherein two or one color difference components are restored by the nearest neighbor method. 16. The image data thinning / interpolating apparatus according to claim 7, wherein one color difference component is restored by the nearest neighbor method, and the other color difference component is restored by the cubic interpolation method. . 17. A first pixel group in the luminance component is Xy × Yy pixels, a second pixel group is m × n pixels, and a third pixel group in one color difference component is Xu × Yu pixels,
The fourth pixel group is mu × nu pixels, and the fifth pixel group in the other color difference component is Xv × Yv
15. The image data thinning / interpolating apparatus according to claim 13, wherein the pixels and the sixth pixel group are mv × nv pixels. 18. The m, the n, the Xy, and the Yy
18. The image data thinning / interpolating apparatus according to claim 17, wherein m-Xy≥3, n-Yy≥3 or 2x <m, 2y <n. 19. An apparatus for interpolating original pixel group data for thinned color image data, wherein a luminance component is equal to or more than two interpolation methods, and two color difference components are equal to or less than the number of luminance component interpolation methods. An image data thinning / interpolation method characterized by the following. 20. An apparatus for thinning out data of an original pixel group for color image data, comprising:
Characterized in that no pixel group in the range of (1) overlaps with the pixel group in the third and fifth ranges of the two color difference components. 21. An apparatus for thinning out data of an original pixel group for color image data, comprising:
Wherein the number of overlapping pixels between the pixel group in the range and the pixel group in the third and fifth ranges in the two color difference components is minimized. 22. An apparatus for thinning out original pixel group data for color image data, wherein the first, third, and fifth pixel groups of a luminance component, a chrominance component, and a chrominance component are each a dot dispersion type. Image data thinning / interpolation method. 23. An image data decimation / interpolation program for causing a computer to realize the functions of the image data decimation / interpolation device according to claim 1. Description: 24. A computer-readable recording medium on which the program according to claim 23 is recorded. 25. An image data decimation / interpolation program for causing a computer to realize the functions of the image data decimation / interpolation method according to claim 19. 26. A computer-readable recording medium on which the program according to claim 25 is recorded.