Image display method and image display device

Patent metadata

Field	Value
Publication number	US-2016180782-A1
Application number	US-201514976673-A
Country	US
Kind code	A1
Filing date	Dec 21, 2015
Priority date	Dec 22, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

Disclosed is a method of displaying an image using an image display device including a front LCD panel and a rear LCD panel overlapping each other that may include displaying an RGB image in the front LCD panel; generating a black-and-white image having a luminance value adjusted by a pixel by signal-processing the RGB image, and displaying the black-and-white image in the rear LCD panel.

First claim

What is claimed is:

1 . A method of displaying an image using an image display device including a front LCD panel and a rear LCD panel overlapping each other, comprising:
displaying an RGB image in the front LCD panel; generating a black-and-white image having a luminance value adjusted by a pixel by signal-processing the RGB image; and displaying the black-and-white image in the rear LCD panel.

2 . The method of claim 1 , wherein generating the black-and-white image comprises:
generating a binary data by binarizing a luminance value of a pixel of a first image based on the RGB image; generating one of a high luminance region expansion binary data and a low luminance region reduction binary data by expanding a high luminance region of the binary data and by reducing a low luminance region of the binary data; and replacing the luminance value of the pixel of the first image according to a value of a pixel of one of the high luminance region expansion binary data and the low luminance region reduction binary data.

3 . The method of claim 2 , wherein generating the first image comprises:
generating an LUT input image from the RGB image through a color matrix conversion; and converting a gray level of the LUT input image with a look-up table where a correlation of the luminance value before and after a gray level conversion is registered.

4 . The method of claim 2 , wherein generating the binary data comprises:
setting a value corresponding to the pixel of the binary data as 1 according to a judgment that the pixel belongs to the high luminance region when of the luminance value of the pixel of the first image is greater than a first threshold value; and setting the value corresponding to the pixel of the binary data as 0 according to a judgment that the pixel belongs to the low luminance region when of the luminance value of the pixel of the first image is smaller than the first threshold value.

5 . The method of claim 4 , wherein generating the high luminance region expansion binary data when the high luminance region is expanded comprises:
when the binary data corresponding to the pixel is 1 and the binary data of an adjacent pixel of the pixel is 0, replacing the binary data of the adjacent pixel with 1.

6 . The method of claim 4 , wherein generating the low luminance region reduction binary data when the low luminance region is reduced comprises:
when the binary data corresponding to the pixel is 0 and the binary data of an adjacent pixel of the pixel is 1, replacing the binary data of the pixel with 1.

7 . The method of claim 5 , wherein when the high luminance region expansion binary data corresponding to the pixel is 1, the luminance value of the pixel of the first image is replaced with a luminance value corresponding to the high luminance region.

8 . The method of claim 2 , wherein a size of one of the expanded high luminance region and the reduced low luminance region is determined by at least one of a distance between the front LCD panel and the rear LCD panel and a size of the RGB image.

9 . The method of claim 1 , wherein generating the black-and-white image comprises:
detecting a high band where a spatial frequency of a luminance value of a pixel of a first image based on the RGB image is greater than a reference value; and replacing the luminance value of the pixel of the first image corresponding to the high band.

10 . The method of claim 9 , wherein generating the first image comprises:
generating an LUT input image from the RGB image through a color matrix conversion; and converting a gray level of the LUT input image with a look-up table where a correlation of the luminance value before and after a gray level conversion is registered.

11 . The method of claim 10 , wherein detecting the high band comprises:
calculating a variance of the luminance value of an adjacent pixel of the pixel of the first image; when the variance is equal to or greater than a second threshold value, judging that the adjacent pixel belongs to the high band and setting a high band judge flag as 1; and when the variance is smaller than the second threshold value, judging that the adjacent pixel does not belong to the high band and setting the high band judge flag as 0.

12 . The method of claim 11 , wherein when the high band flag of the pixel is 1, the luminance value of the pixel of the first image is replaced with one of a luminance value corresponding to the high luminance region and a corresponding luminance value of an output image through a low pass filtering to the first image.

13 . An image display device including a front LCD panel and a rear LCD panel overlapping each other, comprising:
an LCD controller signal-processing an RGB image and supplying the signal-processed RGB image to the front LCD panel; and an LV controller generating a black-and-white image having a luminance value adjusted by a pixel by signal-processing the RGB image and supplying the black-and-white image to the rear LCD panel.

14 . The image display device of claim 13 , wherein the LV controller comprises:
a binarizer generating a binary data by binarizing a luminance value of a pixel of a first image based on the RGB image; a region processor generating one of a high luminance region expansion binary data and a low luminance region reduction binary data by expanding a high luminance region of the binary data and by reducing a low luminance region of the binary data; and a data replacer replacing the luminance value of the pixel of the first image according to a value of a pixel of one of the high luminance region expansion binary data and the low luminance region reduction binary data.

15 . The image display device of claim 14 , wherein the LV controller further comprises:
a color matrix converter generating an LUT input image from the RGB image through a color matrix conversion; and a look-up table converting a gray level of the LUT input image and generating the first image, a correlation of the luminance value before and after a gray level conversion registered in the look-up table.

16 . The image display device of claim 14 , wherein the binarizer sets:
a value corresponding to the pixel of the binary data as 1 according to a judgment that the pixel belongs to the high luminance region when of the luminance value of the pixel of the first image is greater than a first threshold value; and the value corresponding to the pixel of the binary data as 0 according to a judgment that the pixel belongs to the low luminance region when of the luminance value of the pixel of the first image is smaller than the first threshold value.

17 . The image display device of claim 16 , wherein when the high luminance region is expanded and when the binary data corresponding to the pixel is 1 and the binary data of an adjacent pixel of the pixel is 0, the region processor replaces the binary data of the adjacent pixel with 1.

18 . The image display device of claim 16 , wherein when the low luminance region is reduced and when the binary data corresponding to the pixel is 0 and the binary data of an adjacent pixel of the pixel is 1, the region processor replaces the binary data of the pixel with 1.

19 . The image display device of claim 17 , wherein when the high luminance region expansion binary data corresponding to the pixel is 1, the data replacer replaces the luminance value of the pixel of the first image with a luminance value corresponding to the high luminance region.

20 . The i

Assignees

• Lg Display Co Ltd

Inventors

• Nakaya Hideo

Classifications

• G09G2300/023

  Display panel composed of stacked panels · CPC title

• G09G3/3607 Primary

  for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels (display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127) · CPC title

• G09G2320/066

  for control of contrast · CPC title

• G09G2320/0271

  Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping · CPC title

• G09G2340/06

  Colour space transformation · CPC title