Patent ID: 8290261

Claim:
An image processing apparatus, which converts tone characteristics of input images input for respective frames using a tone correction table, and sequentially outputs the converted images as output images, comprising: a holding unit which holds the tone correction table; a generation unit which generates, when a range of luminance values expressed by the input image is divided into a plurality of levels, histogram data indicating the numbers of pixels for respective levels of the plurality of levels by calculating, for the respective levels, the total of the number of pixels in the input image, which have luminance values that belong to an identical level; a calculation unit which calculates, for the respective levels of the plurality of levels the difference between the number of pixels that belong to an identical level using histogram data generated by said generation unit for an input image of a first frame and histogram data generated by said generation unit for an input image of a second frame which was input immediately before the input image of the first frame; a determination unit which determines, based on the differences for the respective levels calculated by said calculation unit, whether or not to update the tone correction table held by said holding unit; an updating unit which updates, when said determination unit determines to update the tone correction table, the tone correction table held by said holding unit; and a unit which outputs a result obtained by converting a tone characteristic of the input image of the first frame using the tone correction table held by said holding unit as an output image of the first frame.