Patent ID: 8139054

Claim:
A luminance compensation apparatus, applied in an electronic apparatus for displaying multimedia data on a display, comprising: an environment detector detecting environment luminance comprising: an image sensor capturing a predetermined number of a plurality of images at different exposure time values; and an image signal processing unit, coupled to the image sensor, obtaining a luminance value for each captured image by the image sensor; a processor, coupled to the environment detector, controlling the image sensor to capture the images according to the different exposure time values, generating a mapping curve comprising a plurality of plots each representing a relationship between the luminance value of one captured image and the exposure time value corresponding thereto, determining a preferred exposure time value which makes the image sensor capture an image having a luminance reference value in response to the mapping curve, wherein the luminance reference value is determined based on a slope of the mapping curve near a middle point of a portion of the mapping curve, and outputting a compensation parameter according to the determined exposure time value; and a luminance compensation unit, coupled to the processor, compensating luminance values of pixels of the multimedia data, which is not related to the captured images, according to the compensation parameter and outputting compensated multimedia data to the display.