Image processing circuit and image display apparatus

• US 20100026731A1
• Filed: 07/28/2009
• Published: 02/04/2010
• Est. Priority Date: 07/31/2008
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Konuma, Yasushi
• Granted Patent: US 8,937,631 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 5/04 using circuits for interfacing with colour displays
• CPC Class Codes: H04N 9/69 for modifying the colour signals by gamma correction controlling camera response for colour signals H04N23/83

Abstract

An image processing circuit includes: a detecting unit detecting pixel regions where luminance levels of image signals exceed a given luminance threshold; and a correcting unit applying basic gamma correction to image signals in regions other than the pixel regions detected, and applying luminance increasing gamma correction to image signals in the pixel regions detected. The luminance increasing gamma correction allows the luminance levels to be increased.

Claims

1. An image processing circuit comprising:

detecting means for detecting pixel regions where luminance levels of image signals exceed a given luminance threshold; and

correcting means for applying basic gamma correction to image signals in regions other than the pixel regions detected, and applying luminance increasing gamma correction to image signals in the pixel regions detected, the luminance increasing gamma correction allowing the luminance levels to be increased.

2. The image processing circuit according to claim 1, wherein

the detecting means further detects whether or not a difference in the luminance levels between the image signals in the pixel regions detected and the image signals in the regions other than the pixel regions detected is larger than a given luminance difference threshold, and

the correcting means applies the luminance increasing gamma correction to the image signals in the pixel regions detected, only when the difference in the luminance levels is larger than the luminance difference threshold.

3. The image processing circuit according to claim 1, further comprising determination means for detecting an area of the pixel regions detected, and determining whether or not the area detected is smaller than a given area threshold, wherein

the correcting means applies the luminance increasing gamma correction to the image signals in the pixel regions detected, only when the determination means has determined that the area detected is smaller than the area threshold.

4. The image processing circuit according to claim 2, further comprising determination means for detecting an area of the pixel regions detected, and determining whether or not the area detected is smaller than a given area threshold, wherein

the correcting means applies the luminance increasing gamma correction to the image signals in the pixel regions detected, only when the determination means has determined that the area detected is smaller than the area threshold.

5. The image processing circuit according to claim 1, further comprising detecting means for detecting an area of the pixel regions detected, wherein

the correcting means applies the luminance increasing gamma correction having a characteristic related to a size of the area detected by the detecting means.

6. The image processing circuit according to claim 1, wherein the correcting means includes a first gamma correction table used for the basic gamma correction, and a second gamma correction table which is separately provided from the first gamma correction table and is used for the luminance increasing gamma correction.

7. The image processing circuit according to claim 1, wherein the correcting means includes a first gamma correction table used for the basic gamma correction and at least one function, and generates a second gamma correction table used for the luminance increasing gamma correction by modulating the first gamma correction table for the basic gamma correction with the function.

8. An image display apparatus comprising:

detecting means for detecting pixel regions where luminance levels of image signals exceed a given luminance threshold;

correcting means for applying basic gamma correction to image signals in regions other than the pixel regions detected, and applying luminance increasing gamma correction to image signals in the pixel regions detected, the luminance increasing gamma correction allowing the luminance levels to be increased; and

displaying means for displaying an image on the basis of the image signals corrected by the correcting means.

9. An image processing circuit comprising:

a detecting unit detecting pixel regions where luminance levels of image signals exceed a given luminance threshold; and

a correcting unit applying basic gamma correction to image signals in regions other than the pixel regions detected, and applying luminance increasing gamma correction to image signals in the pixel regions detected, the luminance increasing gamma correction allowing the luminance levels to be increased.

10. An image display apparatus comprising:

a detecting unit detecting pixel regions where luminance levels of image signals exceed a given luminance threshold;

a correcting unit applying basic gamma correction to image signals in regions other than the pixel regions detected, and applying luminance increasing gamma correction to image signals in the pixel regions detected, the luminance increasing gamma correction allowing the luminance levels to be increased; and

a displaying unit displaying an image on the basis of the image signals corrected by the correcting unit.