Data conversion unit and method

Patent metadata

Field	Value
Publication number	US-10176745-B2
Application number	US-201514885954-A
Country	US
Kind code	B2
Filing date	Oct 16, 2015
Priority date	Oct 23, 2014
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A data conversion unit is disclosed which includes: a transformation portion configured to transform R (red), G (green) and B (blue) sub-pixel data signals of input image data into R, G, B and W (white) sub-pixel data signals; and a brightness reinforcement portion configured to adjust brightness of a transformed W sub-pixel data signal included in the transformed R, G, B, and W sub-pixel data signals based on brightness distribution of the input image data.

First claim

What is claimed is:

1. A display device, comprising:
a data conversion unit comprising:
a transformation circuit configured to transform input red sub-pixel, green sub-pixel, and blue sub-pixel data signals of input image data for an image into transformed red sub-pixel data signal, green sub-pixel data signal, blue sub-pixel data signal, and white sub-pixel data signal;
a histogram analyzer circuit configured to generate a histogram describing brightness distribution of the input image data of the image using the red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal; and
a brightness reinforcement circuit configured to analyze the histogram and to adjust brightness of a transformed white sub-pixel data signal based on the analyzed histogram, wherein the transformed white sub-pixel data signal is included in the transformed red sub-pixel data signal, green sub-pixel data signal, blue sub-pixel data signal, and white sub-pixel data signal, the brightness reinforcement circuit including:
a brightness distribution determiner circuit configured to analyze the histogram to determine the brightness distribution of the input image data for the image;
a tone mapping curve generator circuit configured to generate a tone mapping curve based on the analyzed histogram describing the brightness distribution; and
a brightness adjuster circuit configured to adjust the brightness of the transformed white sub-pixel data signal based on the generated tone mapping curve; and

a display panel for displaying the image.

2. The display device of claim 1 , wherein the brightness distribution determiner circuit is further configured to:
divide color pixel data signals of the input image data for the image into N color pixel data signal groups based on a brightness of each color pixel data signal determined using the histogram describing brightness distribution, where N is at least two; and
identify from the N color pixel data signal groups a maximum pixel data signal group including a largest number of color pixel data signals.

3. The display device of claim 2 , wherein adjusting the brightness of the transformed white sub-pixel data signal comprises adjusting the brightness of a gray scale level range opposite to the maximum pixel data signal group based on the generated tone mapping curve.

4. The display device of claim 2 , wherein the tone mapping curve generator circuit is further configured to generate the tone mapping curve based on the identified maximum pixel data signal group including the largest number of color pixel data signals.

5. The display device of claim 1 , wherein the data conversion unit further comprises a red, green and blue (RGB) reinforcement circuit configured to selectively perform saturation reinforcement for transformed red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal according to a color attribute pattern of the red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal of input image data for the image, wherein the transformed red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal are included in the transformed red sub-pixel data signal, green sub-pixel data signal, blue sub-pixel data signal, and white sub-pixel data signal.

6. The display device of claim 5 , wherein the RGB reinforcement circuit comprises:
a color attribute pattern analyzer circuit configured to analyze the color attribute pattern of the red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal of input image data for the image;
a saturation gain controller circuit configured to selectively generate saturation gain values based on the analyzed color attribute pattern; and
a RGB adjuster circuit configured to adjust saturation of the transformed red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal using the generated saturation gain values.

7. The display device of claim 6 , wherein the saturation gain controller circuit comprises:
a first saturation gain generator circuit configured to generate variable saturation gain values for the transformed red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal responsive to the red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal of input image data for the image corresponding to a chromatic color; and
a second saturation gain generator circuit configured to generate fixed saturation gain values for the transformed red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal responsive to the red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal of input image data for the image corresponding to an achromatic color.

8. The display device of claim 7 , wherein the variable saturation gain values are varied along gray scale values of the red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal of the input image data for the image.

9. The display device of claim 5 , wherein the data conversion unit further comprises a rendering circuit configured to combine the brightness-adjusted transformed white sub-pixel data signal and the saturation-reinforced transformed red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal.

10. The display device of claim 1 , wherein the data conversion unit further comprises a de-gamma circuit configured to perform a de-gamma treatment on the red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal, the de-gamma treated red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal transformed into the transformed red sub-pixel data signal, green sub-pixel data signal, blue sub-pixel data signal, and white sub-pixel data signal.

11. The display device of claim 1 , wherein the transformed red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal are not adjusted based on the brightness distribution of the input image data of the image, wherein the transformed red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal are included in the transformed red sub-pixel data signal, green sub-pixel data signal, blue sub-pixel data signal, and white sub-pixel data signal.

12. The display device of claim 1 , wherein the brightness reinforcement circuit is further configured to:
determine one of a plurality of histograms that corresponds to the analyzed histogram of the input image data, each of the plurality of histograms associated with a distinct tone mapping curve;
select a tone mapping curve associated with the determined one histogram from the plurality of histograms that corresponds to input image data and
adjust the brightness of the white sub-pixel data signal according to the selected tone mapping curve.

13. A method of operation in a display device, the method comprising:
transforming, by the display device, red sub-pixel, green sub-pixel, and blue sub-pixel data signals of input image data of an image into transformed red sub-pixel data signal, green sub-pixel data signal, blue sub-pixel data signal, and white sub-pixel data signal;
generating a histogram describing a brightness distribution of the input image data of the image using the red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal;
analyzing, by the display device, the histogram describing the brightness distribution determined from the red sub-pixel data signal, green sub-pixel data signal, and blue sub-pixel data signal of the

Assignees

• Lg Display Co Ltd

Inventors

• Kang Dong Woo

Classifications

• G09G3/3607

  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

• G09G3/2074 Primary

  using sub-pixels · CPC title

• G09G2320/0673

  for control of gamma adjustment, e.g. selecting another gamma curve · CPC title

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G09G2320/0271

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