KR100814350B1 - Correction apparatus for correcting asymmetrical truncation error of image data of portable terminal and method thereof and display module to which the method is applied - Google Patents

Abstract

The present invention relates to an image data correction apparatus and method for correcting image data input to an LCD module of a portable terminal. The image data correction apparatus includes a cutting error estimating unit and a cutting error compensating unit, estimates an error of the asymmetrically cut RGB image data input to the LCD module of the portable terminal, and compensates the corresponding image data according to the estimation result. Will be displayed on the screen. The image data correction device can eliminate the case where the gray pixel becomes color by detecting and correcting the pixel having the color by the gray pixel or the asymmetrical cutting of the original image. In addition, the image data correction apparatus detects a blue pixel or a reddish pixel and interpolates the image data of the pixel using image data of adjacent pixels, thereby eliminating the step phenomenon or the spot that occurs in the image. It becomes possible. As a result, not only can the original image be accurately reproduced on the LCD panel of the portable terminal, but also a clear image can be displayed.

Description

Correction apparatus for correcting asymmetrical truncation error of image data of a mobile terminal, and a method and a display module to which the method is applied {Asymmetric Truncation Error Compensation device for mobile phone and method about and display module using the device}

1 is a block diagram schematically illustrating data transmitted from a CPU of a terminal to an LCD module in a general portable terminal.

2 is a block diagram showing the configuration of 16-bit RGB image data transmitted to the LCD module in a general portable terminal.

3 is a block diagram schematically illustrating an LCD module to which an image data correction device according to an exemplary embodiment of the present invention is applied.

4 is a block diagram schematically illustrating an internal configuration of the image correcting apparatus of FIG. 3.

FIG. 5 is a graph illustrating display output brightness levels for input of 16-bit RGB image data transmitted to an LCD module in a general portable terminal.

6 is a flowchart sequentially illustrating operations of a gray pixel detector of a truncation error estimator of an image data correction device according to an exemplary embodiment of the present invention.

7 is a flowchart sequentially illustrating operations of a blue-red pixel detector of a truncation error estimation unit of an image data correction device according to an exemplary embodiment of the present invention.

8 is a diagram exemplarily illustrating shapes of boundary lines detected according to a preferred embodiment of the present invention.

FIG. 9 is a diagram illustrating definitions of pixels required for an operation of an interpolation direction setting unit of a truncation error estimation unit of an image data correction device according to an exemplary embodiment of the present invention.

10 is a flowchart sequentially illustrating operations of an interpolation direction setting unit of a truncation error estimator of an image data correction device according to an exemplary embodiment of the present invention.

FIG. 11 illustrates the gray level of gray pixels displayed on the LCD panel by being compensated by the gray pixel compensator of the truncation error compensator of the image data compensator according to an exemplary embodiment of the present invention. These graphs are shown for comparison with the gradation of.

12 is a diagram comparing an actual image compensated by a gray pixel compensator according to a preferred embodiment of the present invention with an image by a conventional method.

13 is a flowchart sequentially illustrating operations of a pixel interpolator of a truncation error compensator of an image data compensator according to an exemplary embodiment of the present invention.

14 are graphs illustrating a state in which a step phenomenon in a blue image or a red image is removed by a pixel interpolator according to an exemplary embodiment of the present invention.

15 is a view comparing an image corrected by the image data correction apparatus according to an embodiment of the present invention with an image by a conventional method.

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

300: LCD Module

302: Image data correction device

310: cutting error estimation unit

312: gray pixel detection unit

314: blue-red pixel detection unit

316: interpolation direction setting unit

320: cutting error compensation unit

322: gray pixel compensation unit

324: pixel interpolation unit

330: graphics memory

340: drive unit

350: LCD panel

The present invention relates to a display module for improving the image quality of a portable terminal, an image data correction apparatus mounted thereon, and a method thereof, and more particularly, to an error of asymmetrically cut RGB image data input to an LCD module of a portable terminal. The present invention relates to an image data correction apparatus and method, and a display module to which the original method can be accurately reproduced by estimating the type of the data and compensating the image data according to the estimation result and displaying the same on the LCD panel.

Liquid crystal displays (hereinafter referred to as "LCDs") are thin and light, and are widely used as monitors or TVs because of their excellent characteristics such as high definition, high resolution, and low power consumption. In particular, LCD is widely used as a display panel of a small portable terminal (eg, a mobile phone, a DMB terminal, etc.).

In general, a TV, a monitor, and the like are inputted with red (R), green (G), and blue (B) video signals of 8 bits for each pixel, and display each screen at 30 frames or more per second. It is possible to output vivid colors and images.

However, portable terminals such as mobile phones output 15 frames per second in order to extend battery life and minimize power consumption, and use R, G, and B video signals each composed of 5, 6, and 5 bits. 1 is a block diagram illustrating an LCD module 110 of a general portable terminal.

Referring to FIG. 1, the CPU 100 of the portable terminal receives image data from the outside, wherein the received image data includes a luminance signal Y and color difference signals Cb and Cr. And color difference signals are composed of 8 bits each. The CPU 100 includes a color space converter 102 and an asymmetric truncation 104 to convert the image data received from the outside into a suitable data form of the LCD module. 110).

The image space converter 102 receives 8-bit data for Y, Cb, and Cr, and converts the 8-bit data into R, G, and B image data each consisting of 8 bits.

The asymmetric truncation unit 104 receives 8-bit RGB image data output from the image signal converter, and erases 2, 3, and 2 bits from the least significant bits of the received RGB image data, respectively. The data is reconstructed into bits and transmitted to the LCD module. In this case, since the green color has a large contribution to luminance information sensitive to the human eye, one bit of information is added to the red and blue colors.

2 is a diagram illustrating a process of processing 16-bit RGB image data transmitted to the LCD module 110. As shown in FIG. 2, B (5 bits), G (6 bits), and R (5 bits) image data are sequentially arranged from the least significant bit (LSB), so that image data forming 16 bits in total is input to the LCD module. do.

By reducing the amount of data to be transmitted per frame through the above-described method, the data transfer speed can be reduced by half, and as a result, power consumption of the CPU and the LCD module to be processed can be reduced.

However, as described above, the asymmetrically truncated RGB image signal has a problem in that color appears in a gray image having a half gray scale.

Conventional techniques to solve this problem, by using the LUT to adjust the number of input digital bits of the RGB three primary colors R: 5, G: 6, B: 5 so that the luminance is a constant correlation color temperature while maintaining the original value In this paper, it is proposed to adjust R: 6, G: 6, and B: 6 to output.

However, such a conventional technique has an improvement effect in terms of chromaticity coordinates of three primary colors and correlated color temperature (CCT) of gray scales according to changes of RGB input values for all image inputs, but red color. Stairs and spots occur due to the lack of gray and blue colors, and problems of color reproduction in grayscale images occur due to inaccurate correlation color temperature, resulting in deterioration of color and clarity of the displayed image. .

An object of the present invention for solving the above problems is to correct the image data asymmetrically cut from the original image data transmitted to the LCD module, and to reconstruct image data similar to the original image, thereby maintaining a constant correlation color temperature. Another object of the present invention is to provide an image data correcting apparatus and method for an LCD module, which enable accurate color reproduction while being close to an original image.

Another object of the present invention is to provide an LCD module that is equipped with the above-described image data correction device or by applying the method to realize accurate color reproduction and provide a clear image.

A feature of the present invention for achieving the above-described technical problem relates to an image data correction apparatus for compensating and displaying image data in an LCD module of a portable terminal,

Receives R, G, and B image data in which a part of the lower bits of the original image data are asymmetrically truncated for each pixel from the CPU of the terminal, and there is an error due to the asymmetry truncation from the image data received for each pixel. A truncation error estimator for estimating whether

And a truncation error compensator for compensating and outputting an error of the corresponding image data with respect to the pixel estimated as an error by the truncation error estimator, and displaying the image data compensated by the truncation error compensator on a display panel. .

The truncation error estimator of the image data correction device having the above-described feature includes a gray pixel detector, and the gray pixel detector determines whether the gray pixel is a gray pixel for each pixel, and detects the gray pixel of the pixel determined as the gray pixel. Set the flag to a preset value,

The truncation error compensator includes a gray pixel compensator, and the gray pixel compensator replaces the red and blue image data of the pixel for which the gray pixel detection flag is set to a predetermined value with the green image data.

In addition, the truncation error estimator of the image data correcting apparatus having the above-described features includes a blue-red pixel detector, and the blue-red pixel detector determines whether the pixel is a blue pixel or a reddish pixel. If it is a blue pixel, the blue pixel detection flag for the pixel is set to a preset value, and if it is a red pixel, the red pixel detection flag for the pixel is set to a preset value,

The truncation error compensator includes a pixel interpolator, and when the blue and red pixel detection flags for each pixel are set to a predetermined value, the interpolation error compensator interpolates the image data of the corresponding pixel using the image data of adjacent pixels. desirable.

In addition, the truncation error estimator of the image data correction device having the above-described feature includes a blue-red pixel detector and an interpolation direction setting unit, and the blue-red pixel detector includes a blue pixel or a red pixel for each pixel. Determine whether the image is a blue pixel, and if the blue pixel is a blue pixel detection flag for the pixel, the red pixel detection flag for the pixel is set to a preset value.

When the blue or red pixel detection flag is set to a preset value by the blue-red pixel detection unit, the interpolation direction setting unit compares image data of adjacent pixels of the corresponding pixel to determine an interpolation direction for the corresponding pixel. Set the interpolation direction flag for the pixel to a preset value according to the interpolation direction.

The truncation error compensator includes a pixel interpolator, and the pixel interpolator interpolates the image data of each pixel using the image data of adjacent pixels using a blue or red pixel detection flag and an interpolation direction flag for each pixel. desirable.

According to another aspect of the present invention, a method of correcting image data of a display module includes R, G, and B image data in which a part of the lower bits of the original image data is asymmetrically cut on each pixel for display on a display panel of a portable terminal. The method relates to a method of compensating image data in a display module that receives a signal.

(a) R, G, and B image data for each pixel satisfy the condition of {((G >> 2) == odd number) && ((R == B) && (R == G-4))} Determining whether it is satisfied;

(b) setting the gray pixel detection flag for the pixel satisfying the above condition to a preset value;

(c) replacing the R and B image data of the pixel in which the gray pixel detection flag is set to a preset value with the G image data of the pixel;

It is characterized in that the gray pixel to prevent the color from appearing.

According to another aspect of the present invention, a method of correcting image data of a display module includes R, G, and B images in which a part of the lower bits of the original image data is asymmetrically cut on each pixel for display on a display panel of a portable terminal. The present invention relates to a method of correcting image data in a display module that receives data.

(a) if the B image data of the pixel is larger than the R image data and the G image data by a predetermined value or more, setting the blue pixel detection flag of the pixel to a preset value;

(b) setting the red pixel detection flag of the pixel to a preset value if the R image data of the corresponding pixel is larger than a predetermined value than the B image data and the G image data;

(c) If the blue or red pixel detection flag of the corresponding pixel is set to a preset value, it is determined whether the pixel is a boundary area. If the pixel is a boundary area, both the blue and red pixel detection flags of the pixel are determined. Setting to '0';

(d) detecting a pixel in which the blue pixel detection flag or the red pixel detection flag is set to a preset value, interpolating the detected image data using the image data of adjacent pixels, and both the blue and red pixel detection flags are ' Not interpolating the pixel set to 0 ';

It is characterized in that for detecting the blue (red) pixels or red (Reddish) pixels that occur unevenness or stair phenomenon to compensate for this.

According to another aspect of the present invention, a method of correcting image data of a display module includes R, G, and B images in which a part of the lower bits of the original image data is asymmetrically cut on each pixel for display on a display panel of a portable terminal. The present invention relates to a method of correcting image data in a display module that receives data.

(a) if the B image data of the pixel is larger than the R image data and the G image data by a predetermined value or more, setting the blue pixel detection flag of the pixel to a preset value;

(b) setting the red pixel detection flag of the pixel to a preset value if the R image data of the corresponding pixel is larger than a predetermined value than the B image data and the G image data;

(c) If the blue or red pixel detection flag of the pixel is set to a preset value according to step (a) or (b), it is determined whether the pixel is a boundary area, and if the pixel is a boundary area, Setting both the blue and red pixel detection flags of the pixel to '0';

(d) If the corresponding pixel is set to the preset value of the blue or red pixel detection flag according to (a) or (b), the image data of the adjacent pixels of the corresponding pixel are compared, and the corresponding pixel is Setting an interpolation direction flag to a preset value;

(d) The image data of the pixel in which both the blue and red pixel detection flags are set to '0' is not interpolated, and the image data is interpolated by detecting the pixel in which the blue pixel detection flag or the red pixel detection flag is set to a preset value. Interpolating using image data of adjacent pixels in a direction indicated by an interpolation direction flag;

It is characterized in that for detecting the blue (red) pixels or red (Reddish) pixels that occur unevenness or stair phenomenon to compensate for this.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the image data correction device of the LCD module according to an embodiment of the present invention.

FIG. 3 is a block diagram schematically showing the configuration of the LCD module 300 equipped with the image data correction device 302 according to the preferred embodiment of the present invention, and FIG. 4 is the image data correction device 302 of FIG. It is a block diagram schematically showing the configuration.

Referring to FIG. 3, the image data correcting apparatus 302 according to the present embodiment includes a cutting error estimating unit 310 and a cutting error compensating unit 320, and the image data correcting apparatus 302 is provided in the LCD module. After receiving and processing the image data input to the LCD module is mounted and transmitted to the graphic memory 330 of the LCD module. The driver 340 of the LCD module 300 transmits and displays the image data stored in the graphic memory 330 to the LCD panel 350. Therefore, by estimating an error of the image data asymmetrically truncated by the truncation error estimator 310 and performing compensation for a pixel having an estimated error through the truncation error compensator, a clear image is displayed.

Referring to FIG. 4, the truncation error estimator 310 includes a gray pixel detector 312, a blue-red pixel detector 314, and an interpolation direction setting unit 316.

The gray pixel detection unit 312 detects gray pixels that may generate color in gray-level scale due to asymmetrical cutting of the original image data. The red color consists of 5 bits and the green color consists of blue and 6 bits. The 64 gradations that can be represented can be divided into R = G = B and G> (R = B). Therefore, the green data consisting of 6 bits in the 256-level image data input from 0 to 255 is 0, 4, 8, 12, 16,... … Red and Blue data, which is input at four level intervals and consists of 5 bits, is 0, 8, 16, 24,. … It is input at 8 level intervals.

For example, gray pixels of RGB (R_64, G_64, B_64) become RGB (R_64, G_64, B_64) to retain gray pixels even though they are bit-cut. It becomes RGB (R_64, G_68, B_64), and the problem which makes a color stand out arises. 5 is a graph showing gray pixels that are colored by asymmetric bit truncation. 5 is the original image data for gray images input to the CPU of the LCD, each of which consists of 8-bit RGB image data, and the vertical axis is bit-cut and reconstructed into RGB image data of 5, 6, and 5 bits, respectively. Image data input to. In FIG. 5, gray areas represent gray pixels that are colored by asymmetric bit cutting.

As described above, gray pixels having a color by asymmetric bit truncation for RGB image data are generated in gray pixels that are multiples of 4 and not multiples of 8. Accordingly, the gray pixel detector 312 detects gray pixels having a color by asymmetric bit truncation.

6 is a flowchart for sequentially explaining the operation of the gray pixel detection unit 312. Hereinafter, an operation of the gray pixel detector will be described in detail with reference to FIG. 6.

First, if G data shifted two bits in the LSB direction in the pixel is odd number, R data is equal to B data, and R data is equal to (G-4) ((G >> 2) = = odd number) && ((R == B) && (R == G-4))) (step 500), after setting the gray pixel detection flag (G_info) for that pixel to '1' (step 510 Exit. Otherwise, the gray pixel detection flag G_info for the pixel is set to '0' (step 520), and then ends.

The gray pixel detection flag for all pixels is set using the aforementioned gray pixel detector 312, and the pixel in which the gray pixel detection flag is set to '1' is compensated by the truncation error compensator.

On the other hand, the blue-red pixel detector 314 is for detecting pixels of blue and red gradation in which staircases and spots occur. In general, staircases and smudges that occur in blue or red gradations are mainly prominent in blue and red images. Accordingly, the blue-red pixel detection unit 314 detects blue and red pixels, which are mainly caused by stair and unevenness, and sets the blue pixel detection flag B_info and the red pixel detection flag R_info to '1'. .

Hereinafter, the operation of the blue-red pixel detector 314 will be described sequentially with reference to FIG. 7.

If the average value of the blue image data of the corresponding pixel and the eight pixels of upper, lower, left, and right sides is 10 times larger than the average value of the red image data and the green image data of the same pixels (step 600), the blue pixel detection flag B_info is determined. Set to '1' and set the red pixel detection flag R_info to '0' (step 610).

If the average value of the red image data of the corresponding pixel and the eight pixels of upper, lower, left, and right sides is 10 times larger than the average value of the blue image data and the green image data of the same pixels (step 620), the red pixel detection flag R_info The value is set to '1' and the blue pixel detection flag B_info is set to '0' (step 630).

If not included in steps 600 and 620, the red pixel detection flag R_info and the blue pixel detection flag B_info are both set to '0' (step 640), and the process ends.

The pixel in which the red or blue pixel detection flag is set to '1' by the above-described blue-red pixel detector 314 is compensated by the truncation error compensator.

Next, it is detected whether or not the corresponding pixel is in the boundary area (step 650). If the corresponding pixel is in the boundary area, the blue and red pixel detection flags are all set to '0' (step 660). . In this case, whether or not the corresponding pixel is an edge region is determined using a general edge detection method, and since the edge detection method is already well known, a detailed description thereof will be omitted. For reference, the blue-red pixel detection unit 314 of the correction apparatus according to the present invention has one pixel edge (see (a) of FIG. 8) and a half pixel edge (see (b) and (c) of FIG. 8). In the case of 1 Pixel Bounce (refer to (d) and (e) of FIG. 8), the boundary area is determined, but the scope of the present invention is not limited to such edge detection method.

In this way, it is determined whether each of the pixels is in the boundary region, and if it corresponds to the boundary region, both the red and blue pixel detection flags R_info and B_info of the pixel are set to '0', so that the truncation error compensation unit By not compensating, the sharpness of the original image can be maintained.

Meanwhile, the interpolation direction setting unit 316 sets the interpolation direction of the blue and red pixels detected by the blue-red pixel detection unit 314. Hereinafter, operations of the interpolation direction setting unit will be described in detail with reference to FIGS. 9A to 9B and FIG. 10.

First, FIG. 9A illustrates a pixel P _{(0,0) for} which the interpolation direction is to be set, and pixels adjacent to the pixel, and FIG. 9B illustrates arrows of adjacent pixels. It is shown as. 10 is a flowchart for sequentially explaining the operation of the interpolation direction setting unit.

Referring to FIG. 10, first, G _X , G _Y , G _D1 , and G _D2 are calculated according to Equation 1 (step 800).

Next, the largest value among the calculated G _X , G _Y , G _D1 , and G _D2 is detected, and this value is set to G _MAX (step 910).

If G _MAX is G _X , the interpolation direction flag D_info is set to '0' (step 920).

If G _MAX is G _Y , the interpolation direction flag is set to '1' (step 930).

If G _MAX is G _D1 , the interpolation direction flag is set to '2' (step 940).

If G _MAX is G _D2 , the interpolation direction flag is set to '3' (step 950).

The interpolation direction flag is set for the pixels in which the red or blue pixel detection flag is set to '1' by the above-described interpolation direction setting unit. If the interpolation direction flag is set to '0', the X direction of FIG. 9 (b) is the interpolation direction. If the interpolation direction flag is set to '1', the Y direction of FIG. 9 (b) is the interpolation direction. If the interpolation direction flag is set to '2', the D1 direction in FIG. 9 (b) is the interpolation direction. If the interpolation direction flag is set to '3', the D2 direction in FIG. 9 (b) is interpolated. Direction.

Hereinafter, the configuration and operation of the truncation error compensator 320 of the image data correcting apparatus according to an exemplary embodiment of the present invention will be described in detail.

The truncation error compensator 320 includes a gray pixel compensator 322 and a pixel interpolator 324, and a gray pixel detection flag G_info and a red color for each pixel set by the truncation error estimator 310 are included. Image data of each pixel is compensated using the pixel detection flag R_info, the blue pixel detection flag B_info, and the interpolation direction flags D_info.

 The gray pixel compensator 322 checks whether the gray pixel detection flag G_info is set to '1', and if the gray pixel detection flag is set to '1', the gray image compensator 322 displays the red image data and the blue image data value. Is replaced with the value of the green image data of the corresponding pixel.

By executing the above-described gray pixel compensator 322, not only the gray of the original image can be reproduced as it is, but also the expansion effect of gray gray can be obtained, and the additional effect of making the correlation color temperature (CCT) constant You will also get. FIG. 11 is a graph showing gray scales displayed on an LCD panel compensated by a gray pixel compensator according to an exemplary embodiment of the present invention, and is displayed in comparison with an original image, camera image data, and gray scales in a terminal CPU. .

12 is a view comparing a conventional image and a conventional image compensated by a gray pixel compensator according to a preferred embodiment of the present invention, (a) is an image according to a conventional method, and (b) is The image is compensated accordingly. 12, it can be seen that the gray gradation has been removed by the compensation according to the present invention.

Meanwhile, the pixel interpolation unit 324 interpolates the pixel using the red and blue pixel detection flags R_info and B_info and the interpolation direction flag D_info for each pixel, thereby eliminating the step and unevenness of the image. Done. 13 is a flowchart for sequentially explaining an operation of the pixel interpolator 324 according to an exemplary embodiment of the present invention. Hereinafter, an operation of the pixel interpolator 324 will be described in detail with reference to FIG. 13.

First, if R_info and B_info are both set to '0' (step 1200), the process ends without compensating for the truncation error.

If R_info or B_info is set to '1' and D_info is '0' (step 1210), the corresponding image data P _(0,0 ) is corrected by Equation 2 below (step 1212). .

If R_info or B_info is set to '1' and D_info is '1' (step 1220), the corresponding image data P _(0,0 ) is corrected by Equation 3 below (step 1222). .

If R_info or B_info is set to '1' and D_info is '2' (step 1230), the corresponding image data P _(0,0 ) is corrected by Equation 4 below (step 1232).

If R_info or B_info is set to '1' and D_info is '3' (step 1240), the corresponding image data P _(0,0 ) is corrected according to Equation 5 below (step 1242).

The image data correction device according to the present invention determines the interpolation direction using the interpolation direction flag as described above, and interpolates the image data for the pixel using the image data of the pixels located in the interpolation direction. It compensates for errors caused by asymmetric bit truncation.

14 (a), it can be seen that the step phenomenon occurring in the blue (Bluish) image is removed by the correction device according to the present invention, and through FIG. 14 (b), the correction device according to the present invention. As a result, it can be seen that the step phenomenon occurring in the reddish image is removed.

15 is a view to confirm the effect according to the present invention, Figure 15 (a) is an image displayed on the LCD panel according to the conventional method, Figure 15 (b) is a correction device according to the present invention The image displayed on the applied LCD panel. Referring to FIG. 15, it can be seen that steps and spots are removed from an image displayed on the LCD panel to which the correction device according to the present invention is applied.

The LCD module according to the preferred embodiment of the present invention stores the image data compensated by the cutting error compensator in the graphics memory 330, and the driver transmits and displays the image data stored in the graphics memory to the LCD panel, It is possible to eliminate the step phenomenon or the uneven phenomenon caused by the asymmetrical cutting of the image data.

On the other hand, the LCD module according to another embodiment of the present invention is the image data, gray pixel detection flag, red pixel detection flag, blue pixel detection flag and interpolation direction flag for each pixel output from the truncation error estimator of the image data correction device. Save them to graphics memory. In addition, the truncation error compensator of the image data compensator reads information about each pixel stored in the graphic memory, corrects the image data for each pixel, and transmits the image data to the driver to display the corrected image data on the LCD panel. To be able.

The LCD module according to the present exemplary embodiment may use the pixel data and the information about the flags stored in the graphic memory for other purposes.

The present invention has been described above with reference to preferred embodiments thereof, but this is merely an example and does not limit the present invention. In addition, one of ordinary skill in the art to which the present invention pertains that various modifications and applications not exemplified herein are possible in order to improve the performance of the LCD module without departing from the essential characteristics of the present invention. There will be. And differences relating to such modifications and applications should be construed as being included in the scope of the invention as defined in the appended claims.

According to the present invention, by accurately compensating the asymmetrical cut-out image data input to the LCD module of the portable terminal, it is possible to solve the problem that the gray pixels have a color, and to maintain a constant color temperature of the gray image.

In addition, by accurately compensating the asymmetrical cut image data input to the LCD module of the portable terminal according to the present invention, by preventing the occurrence of stains or stair phenomenon in the blue (Redish) image or red (Reddish) image, the original image Accurate color reproduction close to.

In addition, compared to the conventional method using the LUT, the present invention can express more grayscales through interpolation of red and blue image data, and as a result, more colors can be reproduced on an actual LCD panel.

In addition, the LCD module according to the present invention can reduce the power consumption and display image data close to the original image by using a 16-bit interface with the CPU and other components of the portable terminal. Therefore, the LCD module according to the present invention will be particularly suitable as a display module of a portable broadcast receiver such as a DMB phone which needs to be used for a long time.

Claims (14)

Receives R, G, and B image data in which a part of the lower bits of the original image data are asymmetrically truncated for each pixel, and estimates whether an error due to the asymmetric truncation exists from the received image data for each pixel. A truncation error estimator; A truncation error compensator for compensating and outputting an error of the corresponding image data with respect to a pixel estimated to have an error by the truncation error estimation unit; And displaying the image data compensated by the cutting error compensator on a display panel. The display apparatus of claim 1, wherein the truncation error estimator includes a gray pixel detector. The gray pixel detector determines whether the gray pixel is a gray pixel for each pixel, and sets the gray pixel detection flag for the pixel determined as the gray pixel to a preset value. The truncation error compensator includes a gray pixel compensator, And the gray pixel compensator replaces red and blue image data of a pixel in which a gray pixel detection flag is set to a predetermined value with green image data. The display device of claim 1, wherein the truncation error estimator comprises a blue-red pixel detector. The blue-red pixel detector determines whether the pixel is a blue pixel or a red pixel for each pixel, and if the blue pixel is a blue pixel, sets the blue pixel detection flag for the pixel to a predetermined value, In the case of a pixel, the red pixel detection flag for the corresponding pixel is set to a preset value. The truncation error compensation unit includes a pixel interpolation unit, And the pixel interpolation unit interpolates the image data of the pixel using the image data of adjacent pixels when the blue and red pixel detection flags for each pixel are set to a predetermined value.  The display apparatus of claim 1, wherein the truncation error estimator comprises a blue-red pixel detector and an interpolation direction setter. The blue-red pixel detector determines whether the pixel is a blue pixel or a red pixel for each pixel, and if the blue pixel is a blue pixel, sets the blue pixel detection flag for the pixel to a predetermined value, In the case of a pixel, the red pixel detection flag for the corresponding pixel is set to a preset value. When the blue or red pixel detection flag is set to a preset value by the blue-red pixel detection unit, the interpolation direction setting unit compares image data of adjacent pixels of the corresponding pixel to determine an interpolation direction for the corresponding pixel. According to the interpolation direction, the interpolation direction flag for the pixel is set to a preset value. The truncation error compensation unit includes a pixel interpolation unit, And the pixel interpolation unit interpolates the image data of each pixel using the image data of adjacent pixels using a blue or red pixel detection flag and an interpolation direction flag for each pixel. The pixel detection unit of claim 3 or 4, wherein the blue-red pixel detection unit detects whether the blue or red pixel detection flag is a boundary area for a pixel set to a preset value, and if the pixel is detected as a boundary area, Wherein both the blue and red pixel detection flags for the pixel are set to '0', And the pixel interpolation unit of the truncation error compensator does not interpolate the image data of the pixel when both the blue and red pixel detection flags of the specific pixel are '0'. In the display data correction method of the display module for receiving the image data of the R, G, B asymmetrically cut a portion of the original image data for each pixel for display on the display panel of the portable terminal, (a) R, G, and B image data for each pixel satisfy the condition of {((G >> 2) == odd number) && ((R == B) && (R == G-4))} Determining whether it is satisfied; (b) setting the gray pixel detection flag for the pixel satisfying the above condition to a preset value; (c) replacing the R and B image data of the pixel in which the gray pixel detection flag is set to a preset value with the G image data of the pixel; And a gray pixel to prevent the color from appearing. In the display data correction method of the display module for receiving the image data of the R, G, B asymmetrically cut a portion of the original image data for each pixel for display on the display panel of the portable terminal, (a) If the average value of B image data of the corresponding pixel and neighboring pixels is larger than the average value of the R image data and the average value of the G image data of the corresponding pixel and neighboring pixels, the blue pixel detection flag of the corresponding pixel is preset. Setting to a value; (b) If the average value of the R image data of the pixel and the surrounding pixels is larger than the average value of the B image data of the pixel and the surrounding pixels and the average value of the G image data, the red pixel detection flag of the pixel is preset. Setting to a value; (c) detecting a pixel in which a blue pixel detection flag or a red pixel detection flag is set to a preset value, and interpolating the image data of the detected pixel using image data of adjacent pixels; The method of claim 1, further comprising detecting and compensating for blue or red pixels in which smudges or staircases occur. In the display data correction method of the display module for receiving the image data of the R, G, B asymmetrically cut a portion of the original image data for each pixel for display on the display panel of the portable terminal, (a) If the average value of the B image data of the corresponding pixel and the surrounding pixel is larger than the average value of the R image data of the pixel and the surrounding pixel and the average value of the G image data, the blue pixel detection flag of the corresponding pixel is preset. Setting to a value; (b) If the average value of the R image data of the pixel and the surrounding pixels is larger than the average value of the B image data of the pixel and the surrounding pixels and the average value of the G image data, the red pixel detection flag of the pixel is preset. Setting to a value; (c) If the blue or red pixel detection flag of the corresponding pixel is set to a preset value, it is determined whether the pixel is a boundary area. If the pixel is a boundary area, both the blue and red pixel detection flags of the pixel are determined. Setting to '0'; (d) detecting a pixel in which the blue pixel detection flag or the red pixel detection flag is set to a preset value, interpolating the detected image data using the image data of adjacent pixels, and both the blue and red pixel detection flags are ' Not interpolating the pixel set to 0 '; And detecting a blue pixel or a reddish pixel in which a spot or stair occurs, and compensating for the same. In the display data correction method of the display module for receiving the image data of the R, G, B asymmetrically cut a portion of the original image data for each pixel for display on the display panel of the portable terminal, (a) If the average value of B image data of the corresponding pixel and neighboring pixels is larger than the average value of the R image data and the average value of the G image data of the corresponding pixel and neighboring pixels, the blue pixel detection flag of the corresponding pixel is preset. Setting to a value; (b) If the average value of the R image data of the pixel and the surrounding pixels is larger than the average value of the B image data of the pixel and the surrounding pixels and the average value of the G image data, the red pixel detection flag of the pixel is preset. Setting to a value; (c) If the pixel is a blue or red pixel detection flag is set to a predetermined value by the step (a) or (b), the image data of the adjacent pixels of the pixel is compared, and according to the comparison result Setting an interpolation direction flag to a preset value; (d) detecting a pixel in which a blue pixel detection flag or a red pixel detection flag is set to a predetermined value and interpolating the image data of the detected pixel, using the image data of adjacent pixels in the direction indicated by the interpolation direction flag. step; And detecting a blue pixel or a reddish pixel in which a spot or stair occurs, and compensating for the same.  In the display data correction method of the display module for receiving the image data of the R, G, B asymmetrically cut a portion of the original image data for each pixel for display on the display panel of the portable terminal, (a) If the average value of B image data of the corresponding pixel and neighboring pixels is larger than the average value of the R image data and the average value of the G image data of the corresponding pixel and neighboring pixels, the blue pixel detection flag of the corresponding pixel is preset. Setting to a value; (b) If the average value of the R image data of the pixel and the surrounding pixels is larger than the average value of the B image data of the pixel and the surrounding pixels and the average value of the G image data, the red pixel detection flag of the pixel is preset. Setting to a value; (c) If the blue or red pixel detection flag of the pixel is set to a preset value according to step (a) or (b), it is determined whether the pixel is a boundary area, and if the pixel is a boundary area, Setting both the blue and red pixel detection flags of the pixel to '0'; (d) If the corresponding pixel is set to the preset value of the blue or red pixel detection flag according to (a) or (b), the image data of the adjacent pixels of the corresponding pixel are compared, and the corresponding pixel is Setting an interpolation direction flag to a preset value; (d) The image data of the pixel in which both the blue and red pixel detection flags are set to '0' is not interpolated, and the image data is interpolated by detecting the pixel in which the blue pixel detection flag or the red pixel detection flag is set to a preset value. Interpolating using image data of adjacent pixels in a direction indicated by an interpolation direction flag; And detecting a blue pixel or a reddish pixel in which a spot or stair occurs, and compensating for the same.  Receives R, G, and B image data in which a part of the lower bits of the original image data are asymmetrically truncated for each pixel, and estimates whether an error due to the asymmetric truncation exists from the received image data for each pixel. A truncation error estimator configured to set estimation result flags for each pixel according to the estimation result; A graphic memory for storing estimation result flags for each pixel set by each image data and the truncation error estimator; A truncation error compensator for correcting and outputting image data of the corresponding pixel by using estimation result flags for each pixel stored in the graphic memory; A driver which transmits and displays corrected image data output from the truncation error compensator to a display panel; And a display module configured to compensate for and display errors generated as the original image data is asymmetrically cut.  The display apparatus of claim 11, wherein the truncation error estimator includes a gray pixel detector. The gray pixel detector determines whether the gray pixel is a gray pixel for each pixel, and sets the gray pixel detection flag for the pixel determined as the gray pixel to a preset value. The truncation error compensator includes a gray pixel compensator, And the gray pixel compensator replaces the red and blue image data of the pixel for which the gray pixel detection flag is set to a predetermined value with green image data.  The display device of claim 11, wherein the truncation error estimator comprises a blue-red pixel detector. The blue-red pixel detector determines whether the pixel is a blue pixel or a red pixel for each pixel, and if the blue pixel is a blue pixel, sets the blue pixel detection flag for the pixel to a predetermined value, In the case of a pixel, the red pixel detection flag for the corresponding pixel is set to a preset value. The truncation error compensation unit includes a pixel interpolation unit, And the blue and red pixel detection flags for each pixel are interpolated and output image data of the corresponding pixel using the image data of adjacent pixels. The display module according to any one of claims 11 to 13, wherein the display module is an LCD module, and raw image data of R, G, and B input to the LCD module is composed of 5, 6, and 5 bits, respectively. And R, G, and B image data output from the truncation error compensator are 8, 8, and 8 bits, respectively.

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