APPARATUS FOR CONVERTING DATA AND DISPLAY APPARATUS USING THE SAME

• US 20150035847A1
• Filed: 07/28/2014
• Published: 02/05/2015
• Est. Priority Date: 07/31/2013
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Park, Yong Min, Kang, Dong Woo, Han, Tae Seong, Kim, Sung Jin
• Granted Patent: US 9,640,103 B2
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607

Abstract

Disclosed is an apparatus for converting data capable of enhancing sharpness without deterioration of picture quality, and a display apparatus using the same, wherein the apparatus for converting data is provided in the display apparatus with a plurality of unit pixels, each unit pixel with red, green, blue and white sub-pixels, and the apparatus for converting data includes a 4-color data generator for generating 4-color data of red, green, blue and white colors for each unit pixel based on 3-color input data of red, green and blue colors of an input image; and a sharpness enhancer for enhancing sharpness of the input image by correcting white sub-pixel data of the unit pixel corresponding to an edge portion of the input image by a luminance variation of adjacent unit pixels based on white sub-pixel data for each unit pixel.

Claims

1. An apparatus for converting data in a display apparatus including a plurality of unit pixels, each unit pixel with red, green, blue and white sub-pixels, the apparatus comprising:

a 4-color data generator for generating 4-color data of red, green, blue and white colors for each unit pixel based on a 3-color input data of red, green and blue colors of an input image; and

a sharpness enhancer for enhancing sharpness of the input image by correcting white sub-pixel data of a unit pixel of the plurality of unit pixels, the unit pixel corresponding to an edge portion of the input image, by a luminance variation of adjacent unit pixels based on the white sub-pixel data for each unit pixel.

2. The apparatus of claim 1, wherein the sharpness enhancer shifts a matrix-configuration mask by each unit pixel, and corrects white sub-pixel data of each unit pixel corresponding to a central mask cell of the matrix-configuration mask to enhance sharpness of the edge portion of the input image.

3. The apparatus of claim 2, wherein the sharpness enhancer enhances the sharpness of the edge portion of the input image by:

calculating an edge correction value for each unit pixel included in the matrix-configuration mask through a convolution calculation of an edge correction coefficient set in each mask cell of the matrix-configuration mask and the white sub-pixel data of each unit pixel included in the matrix-configuration mask;

calculating a sharpness correction value by adding the edge correction values for the respective unit pixels included in the matrix-configuration mask; and

correcting the white sub-pixel data of the unit pixel corresponding to the central mask cell of the matrix-configuration mask in accordance with the calculated sharpness correction value.

4. The apparatus of claim 3, wherein the edge correction coefficient set in the central mask cell of the matrix-configuration mask has a positive (+) value, and the edge correction coefficient set in remaining mask cells of the matrix-configuration mask except the central mask cell have a negative (−

) value.

5. The apparatus of claim 2, further comprising a sharpness gain value generator for calculating a sharpness gain value for the input image based on an edge intensity for each unit pixel in accordance with the 3-color data of each unit pixel.

6. The apparatus of claim 5, wherein the sharpness gain value generator includes:

an edge intensity calculator for calculating the edge intensity for each unit pixel based on 3-color data for each unit pixel;

an edge distribution index calculator for calculating an edge distribution index for the input image based on a total number of unit pixels and edge intensity for each unit pixel; and

a gain value calculator for generating the sharpness gain value in accordance with the calculated edge distribution index.

7. The apparatus of claim 6, wherein the edge distribution index calculator calculates the edge distribution index by multiplying a ratio of a number of unit pixels whose edge intensity is more than a reference weak edge intensity and a number of unit pixels whose edge intensity is more than a minimum edge intensity and less than the reference weak edge intensity, and a rate of a number of unit pixels whose energy intensity is more than a reference edge intensity in a total number of unit pixels.

8. The apparatus of claim 6, wherein the gain value calculator compares the edge distribution index with a preset edge distribution index threshold value, and calculates the sharpness gain value based on the comparison,

wherein, if the edge distribution index is larger than the edge distribution index threshold value, the sharpness gain value is an initially-set gain value, and

wherein, if the edge distribution index is the same as or smaller than the edge distribution index threshold value, the sharpness gain value is calculated by calculating a first value obtained by dividing the edge distribution index by the edge distribution index threshold value, calculating a second value through the use of exponentiation with a preset index value for the first value, and multiplying the initially-set gain value and the second value.

9. The apparatus of claim 5, wherein the sharpness enhancer enhances the sharpness of edge portion by:

calculating an edge correction value for each unit pixel included in the matrix-configuration mask through a convolution calculation of an edge correction coefficient set in each mask cell of the matrix-configuration mask and the white sub-pixel data of each unit pixel included in the matrix-configuration mask;

multiplying the sharpness gain value and the edge correction value for each unit pixel included in the matrix-configuration mask;

calculating a sharpness correction value by adding the edge correction values for respective unit pixels included in the matrix-configuration mask, wherein each edge correction value is obtained by applying the sharpness gain value thereto; and

correcting the white sub-pixel data of the unit pixel corresponding to the central mask cell of the matrix-configuration mask in accordance with the calculated sharpness correction value.

10. The apparatus of claim 9, wherein the edge correction coefficient set in the central mask cell of the matrix-configuration mask has a positive (+) value, and the edge correction coefficient set in remaining circumferential mask cells of the matrix-configuration mask except the central mask cell has a negative (−

) value.

11. The apparatus of claim 10,

wherein the edge correction coefficient set in each corner mask cell among the circumferential mask cells of the mask has a negative (−

) value, and

wherein the edge correction coefficient set in each of the left, right, upper, and lower-sided mask cells being adjacent to the central mask cell among the circumferential mask cells of the matrix-configuration mask have a negative (−

) value, and the edge correction coefficient thereof is smaller than the edge correction coefficient set in each corner mask cell.

12. A display apparatus comprising:

a display panel including a plurality of unit pixels, each unit pixel with red, green, blue and white sub-pixels, formed in a pixel region defined by a plurality of data lines and scan lines, the data lines crossing the scan lines;

a data converter including a 4-color data generator for generating 4-color data of red, green, blue and white colors for each unit pixel based on 3-color input data of red, green and blue colors of an input image, and a sharpness enhancer for enhancing sharpness of the input image by correcting white sub-pixel data of the unit pixel corresponding to an edge portion of the input image by a luminance variation of adjacent unit pixels based on the white sub-pixel data for each unit pixel; and

a panel driver for supplying a scan signal to the scan line, converting the 4-color data supplied from the data converter into a data voltage, and supplying the data voltage to the data line.

13. The display apparatus of claim 12, wherein the sharpness enhancer shifts a matrix-configuration mask by each unit pixel, and corrects white data of each unit pixel corresponding to a central mask cell of the matrix-configuration mask to enhance sharpness of the edge portion of the input image.

14. The display apparatus of claim 13, wherein the sharpness enhancer enhances the sharpness of edge portion by:

calculating an edge correction value for each unit pixel included in the matrix-configuration mask through a convolution calculation of an edge correction coefficient set in each mask cell of the matrix-configuration mask and white sub-pixel data of each unit pixel included in the mask;

calculating a sharpness correction value by adding the edge correction values for the respective unit pixels included in the matrix-configuration mask; and

correcting the white sub-pixel data of the unit pixel corresponding to the central mask cell of the matrix-configuration mask in accordance with the calculated sharpness correction value.

15. The display apparatus of claim 13, further comprising a sharpness gain value generator for calculating a sharpness gain value for the input image based on an edge intensity for each unit pixel in accordance with the 3-color data of each unit pixel.

16. The display apparatus of claim 15, wherein the sharpness gain value generator includes:

an edge intensity calculator for calculating the edge intensity for each unit pixel based on 3-color data for each unit pixel;

an edge distribution index calculator for calculating an edge distribution index for the input image based on total number of unit pixels and edge intensity for each unit pixel; and

a gain value calculator for generating the sharpness gain value in accordance with the calculated edge distribution index.

17. The display apparatus of claim 16, wherein the edge distribution index calculator calculates the edge distribution index by multiplying a ratio of a number of unit pixels whose edge intensity is more than a reference weak edge intensity a the number of unit pixels whose edge intensity is more than a minimum edge intensity and less than the reference weak edge intensity and a rate of a number of unit pixels whose energy intensity is more than a reference edge intensity in a total number of unit pixels.

18. The display apparatus of claim 16, wherein the gain value calculator compares the edge distribution index with a preset edge distribution index threshold value, and calculates the sharpness gain value based on the comparison,

wherein, if the edge distribution index is larger than the edge distribution index threshold value, the sharpness gain value is an initially-set gain value, and

wherein, if the edge distribution index is the same as or smaller than the edge distribution index threshold value, the sharpness gain value is calculated by calculating a first value obtained by dividing the edge distribution index by the edge distribution index threshold value, calculating a second value through the use of exponentiation with a preset index value for the first value, and multiplying the initially-set gain value and the second value.

19. The display apparatus of claim 15, wherein the sharpness enhancer enhances the sharpness of edge portion by:

calculating an edge correction value for each unit pixel included in the matrix-configuration mask through a convolution calculation of an edge correction coefficient set in each mask cell of the matrix-configuration mask and the white sub-pixel data of each unit pixel included in the matrix-configuration mask;

multiplying the sharpness gain value and the edge correction value for each unit pixel included in the matrix-configuration mask;

calculating a sharpness correction value by adding the edge correction values for respective unit pixels included in the matrix-configuration mask, wherein each edge correction value is obtained by applying the sharpness gain value thereto; and

correcting the white sub-pixel data of the unit pixel corresponding to the central mask cell of the matrix-configuration mask in accordance with the calculated sharpness correction value.

20. The display apparatus of claim 19,

wherein the edge correction coefficient set in each corner mask cell among the circumferential mask cells of the mask has a negative (−

) value, and

wherein the edge correction coefficient set in each of the left, right, upper, and lower-sided mask cells being adjacent to the central mask cell among circumferential mask cells of the matrix-configuration mask have a negative (−

) value, and the edge correction coefficient thereof is smaller than the edge correction coefficient set in each corner mask cell.