Patent ID: 7844112

Claim:
A device for enhancing image contrast, comprising: a gray level distribution statistic circuit to calculate gray level statistic data of an image responsive to an image brightness signal; an adaptive contrast mapping curve calculation circuit to calculate a gray level mapping curve responsive to the gray level statistic data; an inter-frame curve soft-merging circuit to perform inter-frame soft-merging to the gray level mapping curve; a gray level mapping circuit to perform gray level mapping of the input image brightness signal; a first selecting switch with first and second positions, the first position to select providing the image brightness signal to the gray level mapping circuit; a detail separating circuit to separate the input image brightness signal into a detail signal and a non-detail signal when the first selecting switch is in the second position; a second selecting switch to provide the image brightness signal to the gray level mapping circuit when the first selecting switch is in the first position and to provide the non-detail signal to the gray level mapping circuit when the first selecting switch is in the second position; a detail combining circuit to combine the detail signal with a signal output from the gray level mapping circuit; and a third selecting switch to select the signal output from the gray level mapping circuit when the first selecting switch is in the first position and to select a signal output from the detail combining circuit when the first selecting switch is in the second position.