Patent Document ID: 4868651
Application ID: 07195023
Patent Status: 1

Claim One:
1. A process of enhancing a still video image to achieve ideal contrast and brightness, comprising dividing the image into a tableau of pixels, each with a respective luminance value along a gray scale from a predetermined minimum to a predetermined maximum; digitizing the pixel luminance values to respective digital pixel values in a range from a predetermined minimum value to a predetermined maximum digital value; forming a histogram distribution of said digital pixel values by storing, for each possible digital pixel value from said predetermined minimum digital value to said predetermined maximum digital value, a number of pixels having said digital pixel value up to a predetermined finite low threshold number, but storing said threshold number if the number of pixels having said digital pixel value exceeds the threshold number; forming a cumulative histogram from said histogram distribution by storing for each said possible digital pixel value the sum of the stored numbers of pixels having values of said histogram distribution less than or equal to said digital pixel value; normalizing said cumulative histogram by adjusting said stored sums by an appropriate factor such that the adjusted stored sums range between zero and a number equal to said maximum digital value; assigning new digital pixel values for said pixels, wherein said new digital pixel values are that adjusted stored sums for the corresponding digital pixel values of the normalized cumulative histogram; and reproducing a visible image from said new digital pixel luminance values, the reproduced image having an optimal luminance distribution over the entire gray scale, with high contrast and superior detail in bright and dark regions of the reproduced image.