Image processing circuit and image display apparatus

摘要

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.

主权项

1. An apparatus for performing luminance correction to an input image signal, said apparatus comprising:
a processing circuit to (i) detect a first pixel region or regions where luminance levels of image signals representative of an image or images exceed a given luminance threshold in both a horizontal direction and a vertical direction of the image or images and to detect a second pixel region or regions bounded by pixels whose luminance change exceeds a given luminance difference threshold in both the horizontal direction and the vertical direction of the image or images, (ii) obtain an overlap region or regions where the first pixel region(s) and the second pixel region(s) overlap, (iii) determine a size of an area of a respective overlap region, and (iv) apply a first luminance increasing gamma correction or a second luminance increasing gamma correction to image signals in the respective overlap region depending upon the determined size of the area of the respective overlap region, such that (i) when the determined size of the area of the respective overlap region satisfies a first predetermined condition the first luminance increasing gamma correction is applied to the image signals and (ii) when the determined size of the area of the respective overlap region satisfies a second predetermined condition which is different from the first predetermined condition the second luminance increasing gamma correction is applied to the image signals, in which the first luminance increasing gamma correction is different from the second luminance increasing gamma correction, in which both the first luminance increasing gamma correction and the second luminance increasing gamma correction allow the luminance levels to be increased, and in which the first predetermined condition includes being smaller than a first predetermined area and the second predetermined condition includes being smaller than a second predetermined area which is smaller than the first predetermined area, such that (i) when the determined size of the area of the respective overlap region is smaller than the first predetermined area the first luminance increasing gamma correction is applied to the image signals and (ii) when the determined size of the area of the respective overlap region is smaller than the second predetermined area which is smaller than the first predetermined area the second luminance increasing gamma correction is applied to the image signals.