KR20080025823A - Method for transforming image format by interpolation - Google Patents

Abstract

A method for converting an image format by using interpolation is provided to display images in a unit of RGB(Red, Green and Blue) sub pixels by performing RGB image format conversion by the interpolation, thereby improving a resolution and further exactly expressing the images. At least one sub pixel of RGB(Red, Green and Blue) sub pixels is a first sub pixel, and the rest sub pixels are second sub pixels. Second image data of a pixel corresponding to Y luminance information and Cb/Cr chrominance information is generated. By interpolation of the second image data corresponding to neighboring pixels, the second image data corresponding to the second sub pixels is changed.

Description

Method for transforming image format by interpolation

1 is a diagram schematically illustrating a method of converting an image format using interpolation for displaying an image of a delta type LCD according to a preferred embodiment of the present invention.

FIG. 2 is a block diagram schematically illustrating an apparatus for converting a video format according to the video format converting method using the interpolation of FIG. 1.

3 is a block diagram schematically illustrating an image format converter of FIG. 2.

<Explanation of symbols for the main parts of the drawings>

10: video format converter, 11: input unit,

12: storage, 13: control,

14: video format conversion unit, 15: display unit,

141: RGB generator, 142: interpolation processor.

The present invention relates to an image format conversion method, and more particularly, to an image format conversion method using interpolation for displaying an image in units of red, green, and blue sub-pixels.

A typical delta type liquid crystal display (LCD) has an arrangement of pixel structures in which the positions of even and odd rows of sub pixels are alternated with each other. That is, each pixel includes sub-pixels of red, green, and blue, and positions of the red, green, and blue sub-pixels of each of even and odd rows are staggered from each other. .

In the conventional video format conversion method, YCbCr includes image data of Y information (luminance, luminance) and Cb / Cr information (chrominance signal, chrominance). In this case, the 4: 2: 2 format is a ratio of the sample number of the luminance Y and the color difference Cb / Cr, which means that the sample ratio of the color difference is 1/2 of the luminance. That is, the first pixel is generated from the first image information, and the second pixel is generated from the second luminance information and the first color difference signal.

In this case, in the delta type LCD, since even-numbered and odd-numbered subpixel positions are alternately arranged, there is a problem that a stroke or a picture of a letter may appear crooked. In order to solve this problem, an image signal in RGB format may be generated by an average value of two adjacent pixels, but in this case, a stroke of a letter or an edge of a picture may be spread.

According to the present invention, by converting the RBG image format by interpolation and displaying images in units of red, green, and blue sub-pixels, the image format can be changed using interpolation to improve resolution and express images more accurately. It aims to provide a method of exchange.

The present invention provides the first image data of the YCbCr image format including Y luminance information and Cb / Cr chrominance information corresponding to each pixel of a display panel on which image information is displayed. And converting to second image data of an RGB image format corresponding to blue subpixels, at least one of the subpixels becomes a first subpixel, and the remaining subpixels become second subpixels. ,

a) generating the second image data of a pixel corresponding to each of the Y luminance information and the Cb / Cr chrominance information; And

and (b) changing the second image data corresponding to the second sub-pixels by interpolation of the second image data corresponding to adjacent pixels. .

Pixels of the nth column and pixels of the n + 1th column are adjacent to each other, and in the step (b), the second image data corresponding to the second subpixels is equal to {x × (pixels of the nth column). It is preferable to change it by the relation of the second image data) + y × (second image data corresponding to the pixel of the n + 1th column)} / (x + y).

In the subpixels closer to the n-th column of the second subpixels, the x value is greater than the y value, and in the subpixels closer to the n + 1th pixel among the second subpixels, the y-value is greater than the x-value. It is desirable to be large.

In the display panel, pixels in the m th row and pixels in the m + 1 th row are alternately arranged, and in the display panel, pixels in the m th row and subpixels in the m + 1 th pixels are different from each other. It is preferable to arrange in order.

In the pixels of the m th row, the sub pixels are arranged in the order of red, green, and blue sub pixels in the direction of the n + 1 th column from the n th column, and the red sub pixels become the first sub pixel. Preferably, the green and blue subpixels become the second subpixels.

In this case, the second image data corresponding to the green sub-pixels is {2 × (second image data corresponding to the pixel of the nth column) + 1 × (second image data corresponding to the pixel of the n + 1th column. ), And the second image data corresponding to the blue subpixels is changed to {1 × (second image data corresponding to pixels in the nth column) + 2 × (n + 1th). The second image data corresponding to the pixels of the column)} / 3 is preferably changed.

In the pixels of the m + 1 th row, the sub pixels are arranged in the order of green, blue, and red sub pixels in the direction of the n + 1 th column from the n th column, and the green sub pixels are arranged in the first sub pixel. The blue and red sub pixels may be the second sub pixels.

In this case, the second image data corresponding to the blue subpixels is {2 × (second image data corresponding to the pixel of the nth column) + 1 × (2 + th image data corresponding to the pixel of the n + 1th column. ), And the second image data corresponding to the red subpixels is changed to {1 × (second image data corresponding to pixels of n-th column) + 2 × (n + 1). Second image data corresponding to pixels of the first column)} / 3.

In another embodiment, in the pixels of the m + 1 th row, the sub pixels are arranged in the order of blue, red, green sub pixels in the direction of the n + 1 th column from the n th column, and the blue sub pixels The first sub-pixel may be the red and green sub-pixels may be the second sub-pixels.

In this case, the second image data corresponding to the red sub-pixels is {2 × (second image data corresponding to the pixel of n-th column) + 1 × (second image data corresponding to the pixel of n + 1th column. ), And the second image data corresponding to the green sub-pixels is changed to {1 × (second image data corresponding to pixels in the nth column) + 2 × (n + 1th). The second image data corresponding to the pixels of the column)} / 3 is preferably changed.

According to the present invention, by performing the RBG image format conversion by interpolation to display an image in units of red, green, and blue sub-pixels, the resolution can be improved and more accurate image can be expressed.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram schematically illustrating a method of converting an image format using interpolation for displaying an image of a delta type LCD according to an exemplary embodiment of the present invention.

Referring to the drawings, an image format conversion method using interpolation according to the present invention includes a first YCbCr image format including Y luminance information and Cb / Cr color difference information corresponding to each pixel of a display panel on which image information is displayed. The image data is converted into second image data of an RGB image format corresponding to red, green, and blue subpixels included in each pixel. In this case, at least one subpixel among the subpixels becomes the first subpixels A and C, and the remaining subpixels become the second subpixels a, b, c, and d.

An image format conversion method using interpolation includes: (a) generating the second image data of a pixel corresponding to each of the Y luminance information and the Cb / Cr color difference information; And (b) changing the second image data corresponding to the second subpixels by interpolation of the second image data corresponding to adjacent pixels.

In this case, the first image data may be YCbCr image data of 4: 2: 2 format which is typically used in a Joint Photographic Experts Group (JPEG). That is, one Y luminance information may correspond to one pixel, and one Cb / Cr chrominance information may be image data corresponding to two adjacent pixels.

The meaning of the 4: 2: 2 format is the ratio of the number of samples of the luminance (Y) and the color difference (Cb / Cr), which means that the sample ratio of the color difference is 1/2 of the luminance. That is, the first pixels R11, G11 and B11 are generated from the first image information Y00, Cb00 and Cr00, and the second pixels R12, G12 and B12 are the second luminance information Y01 and the first color difference. Generated from signals Cb00 and Cr00.

From the YCbCr image data, RGB image data can be obtained by the relationship according to equation (1). Here, each of R, G, and B becomes red, green, and blue gray, Y is luminance, Cb is blue color difference, and Cr is red color difference.

R = Y + 1.402 × Cr

G = Y-0.344 × Cb-0.714 × Cr

B = Y + 1.772 × Cb

On the other hand, the delta type LCD (Liquid Crystal Display) has a pixel structure of the arrangement as shown on the screen. That is, each pixel includes sub-pixels of red (R), green (G), and blue (B), and the m-th row pixels and the m + 1-th row pixels The positions of each of the red (R), green (G), and blue (B) subpixels are alternately arranged. Here, the pixels of the m th row and the pixels of the m + 1 th row are adjacent to each other, and the pixels of the n th column and the pixels of the n + 1 th column are disposed adjacent to each other.

In the delta type display panel LCD, the pixels of the m-th row and the sub-pixels of the pixels of the m + 1th row may be arranged in different orders. That is, as shown in the figure, the pixels of the m th row are arranged in the order of the subpixels of red (R), green (G), and blue (B), and the pixels of the m + 1 th row are green (G). , Blue (B), and red (R) may be arranged in order. However, as another embodiment, the order of the subpixels is not limited thereto, and may be another order.

In addition, the red subpixel may be a first subpixel in pixels of an m th row, and a green subpixel G21 may be a first subpixel in pixels of an m + 1th row. In addition, the green (G11) and blue (B11) subpixels are the second subpixels in the pixels of the m th row, and the blue (B21) and red (G21) subpixels are the second subpixels in the pixels of the m + 1th row. It can be 2 sub pixels.

However, in the present invention, each pixel is represented by red (R), green (G), and blue (B) subpixels such as a plasma display panel (PDP) and organic light emitting diodes (OLED) display as well as an LCD. It can be applied to various display devices.

In the step (b), the second image data corresponding to the second sub-pixels corresponds to {x × (second image data corresponding to the pixel in the nth column) + y × (n + 1 pixel in the nth column). Second image data)} / (x + y) to be interpolated and changed. In this case, the x value is larger than the y value in the subpixels closer to the pixel of the nth column among the second subpixels, and the y value is larger than the x value in the subpixel closer to the pixel of the n + 1th column among the second subpixels. It is desirable to be large.

Here, the more accurate interpolation relation can be adjusted according to the distance between the subpixels of the LCD, the nonlinear effect of brightness in each subpixel, and the like. That is, the x and y values can be adjusted according to the distance between the subpixels of the LCD, the nonlinear effect of brightness in each subpixel, and the like.

As a specific embodiment of the interpolation relation, the RGB image data a corresponding to the green sub-pixels G11 may be represented as {2 × (second image data corresponding to the pixel of the nth column) + 1 × ( second image data corresponding to pixels of the n + 1th column)} / 3, and RGB image data b corresponding to the blue subpixels B11 is {1 × (pixels of the nth column). It can be changed by the relationship of the second image data corresponding to) + 2 × (the second image data corresponding to the pixel of the n + 1 th column)} / 3. Such an embodiment may be more useful when the distance between the subpixels of the LCD, the brightness at each subpixel, etc. are in a linear relationship.

Further, in the pixels of the m + 1st row, the subpixels are arranged in the order of the green (G21), blue (B21), red (R21) subpixels in the direction of the n + 1th column from the nth column, and the green sub The pixels G21 may be the first sub pixel C, and the blue B21 and red R21 sub pixels may be the second sub pixels c and d.

In this case, the RGB image data c corresponding to the blue subpixels B21 corresponds to {2 × (second image data corresponding to the pixel in the nth column) + 1 × (n + 1th pixel). RGB image data d generated by the relationship of the second image data)} / 3 and corresponding to the red subpixels R21 is equal to {1 × (second image data corresponding to the pixel of the nth column) + 2 × (second image data corresponding to pixels of the n + 1 th column)} / 3.

In the case of the present invention, by displaying an image in units of red, green, and blue sub-pixels, the resolution can be improved and more accurate image representation can be made.

In another embodiment, in the pixels of the m + 1th row, the subpixels are arranged in the order of blue, red, green subpixels in the direction of the n + 1th column from the nth column, and the blue subpixels are the first subpixel. And the red and green subpixels may be second subpixels. In this case, the RGB image data corresponding to the red subpixels is {2 × (second image data corresponding to the pixel of the nth column) + 1 × (second image data corresponding to the pixel of the n + 1th column)} / RGB image data generated by the relation of 3 and corresponding to the green sub-pixels is equal to {1 × (second image data corresponding to the pixel in the nth column) + 2 × (n + 1) corresponding to the pixel in the nth column 2 image data)} / 3.

In the conventional method, since the positions of even-numbered and odd-numbered sub-pixels are staggered from each other, in order to solve a problem in which a stroke or a picture of a letter may be skewed, the average value of two adjacent pixels may be solved. Although it is possible to generate an image signal in the RGB format, in this case, the stroke of the letters or the edges of the picture may be seen to spread.

However, according to the present invention, since images can be displayed in units of red, green, and blue sub-pixel units, the resolution can be improved and the image can be represented more accurately. In addition, it can improve the appearance of the skewed picture and the shape of the strokes of letters or the edges of the picture spread.

FIG. 2 is a block diagram schematically illustrating an apparatus for converting a video format according to the video format converting method using the interpolation of FIG. 1. 3 is a block diagram schematically illustrating an image format converter of FIG. 2.

Referring to the drawings, the image format conversion apparatus 10 using interpolation includes an input unit 11, a storage unit 12, a control unit 13, an image format conversion unit 14, and a display unit 15. Also, the image format converter 14 may include an RGB generator 141 and an interpolation processor 142.

YCbCr format image data may be input through the input unit 11, and image data may be stored in the storage unit 12, or image data may be read from the storage unit 12.

The control unit 13 sends the YCbCr format image data from the input unit 11 or the storage unit 12 to the image format conversion unit 14, and in the image format conversion unit 14 by the method shown in FIG. The image data of the YCbCr format is converted into the image data of the RGB format, so that the display unit 15 can express the image on a display panel such as an LCD.

The image format converter 14 converts the image data of the YCbCr format into the image data of the RGB format by the image format conversion method using interpolation according to the present invention as shown in FIG. 1.

The RGB generator 141 converts the YCbCr format image data into pixel data of each pixel unit, and the interpolation processor 142 converts the converted RGB image data into subpixel units by interpolation. Generate video data.

According to the image format conversion method using interpolation according to the present invention, by converting the RBG image format by interpolation and displaying images in units of red, green, and blue sub-pixels, the resolution is improved and more accurate image representation is achieved. You can make it possible.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it is merely an example, and those skilled in the art may realize various modifications and equivalent other embodiments therefrom. I can understand. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

Claims (10)

The first image data of the YCbCr image format including the Y luminance information and the Cb / Cr color difference information corresponding to each pixel of the display panel on which the image information is displayed is stored in the red, green, and blue sub-fields included in each pixel. Converting to the second image data of the RGB image format corresponding to the pixels, At least one of the subpixels becomes a first subpixel, the remaining subpixels become second subpixels, (a) generating the second image data of a pixel corresponding to each of the Y luminance information and the Cb / Cr color difference information; And and (b) changing the second image data corresponding to the second subpixels by interpolation of the second image data corresponding to neighboring pixels. The method of claim 1, pixels in the nth column and pixels in the n + 1th column are adjacent to each other, In the step (b), the second image data corresponding to the second sub-pixels is equal to {x × (second image data corresponding to the pixel in the nth column) + y × (n + 1th pixel). Image format conversion method using interpolation which is changed by a relationship of corresponding second image data)} / (x + y). The method of claim 2, In the subpixels closer to the n-th column of the second subpixels, the x value is greater than the y value, and in the subpixels closer to the n + 1th pixel among the second subpixels, the y-value is greater than the x-value. Video format conversion method using large interpolation. The method of claim 3, In the display panel, pixels in the m th row and pixels in the m + 1 th row are alternately arranged, and in the display panel, pixels in the m th row and subpixels in the m + 1 th pixels are different from each other. Image format conversion method using interpolation arranged in order. The method of claim 4, wherein In the pixels of the m th row, the sub pixels are arranged in the order of red, green, and blue sub pixels in the direction of the n + 1 th column from the n th column, and the red sub pixels become the first sub pixel. And converting the green and blue subpixels into the second subpixels. The method of claim 5, pixels in the nth column and pixels in the n + 1th column are adjacent to each other, The second image data corresponding to the green sub-pixels is {2 × (second image data corresponding to pixels of n-th column) + 1 × (second image data corresponding to pixels of n + 1th column)} The second image data corresponding to the blue subpixels, which is changed by the relation of / 3, is equal to (1 × (second image data corresponding to the pixel in the nth column) + 2 × (pixel in the n + 1th column). And a second image data corresponding to the &quot; The method of claim 5, In the pixels of the m + 1 th row, The subpixels are arranged in the order of green, blue, and red subpixels in the direction of the n + 1th column from the nth column, the green subpixels are the first subpixel, and the blue and red subpixels are the first subpixel. An image format conversion method using interpolation that becomes 2 sub pixels. The method of claim 7, wherein pixels in the nth column and pixels in the n + 1th column are adjacent to each other, The second image data corresponding to the blue subpixels is {2 × (second image data corresponding to pixels of n th column) + 1 × (second image data corresponding to pixels of n + 1 th column)} And the second image data corresponding to the red sub-pixels is changed by the relationship of / 3, and {1 × (second image data corresponding to pixels of n-th column) + 2 × (pixels of n + 1th column). And a second image data corresponding to the &quot; The method of claim 5, In the pixels of the m + 1 th row, the sub pixels are arranged in the order of blue, red, and green sub pixels in the direction of the n + 1 th column from the n th column, and the blue sub pixels are arranged in the first sub pixel. And the red and green subpixels become the second subpixels. The method of claim 9, pixels in the nth column and pixels in the n + 1th column are adjacent to each other, The second image data corresponding to the red sub-pixels is {2 × (second image data corresponding to pixels of n-th column) + 1 × (second image data corresponding to pixels of n + 1th column)} The second image data corresponding to the green subpixels, which is changed by the relationship of / 3, is equal to (1 × (second image data corresponding to the pixel in the nth column) + 2 × (pixel in the n + 1th column). And a second image data corresponding to the &quot;

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