Method and system for automatic brightness and contrast adjustment of a video source

A method for automatically adjusting brightness and contrast of an input video signal, the method comprising:

• receiving pixel luminance values for each of a plurality of pixels in a frame;
• generating, on a frame-by-frame basis, a pixel luminance histogram based on the pixel luminance values in the frame, wherein the histogram comprises a distribution of luminance values in the frame, the distribution indicating a dynamic range and at least one dominant luminance value for the frame;
• identifying which of a plurality of brightness/contrast properties is exhibited in the frame based on the pixel luminance histogram;
• receiving pixel luminance values for each of a plurality of pixels in a next frame;
• and
• nonlinearly adjusting in real-time the pixel luminance values in the next frame based on the identified brightness/contrast properties exhibited in the preceding frame,
• such that bright or dark dominant areas of an image in the next frame are stretched to enhance the contrast of the dominant luminance values of the next frame without blackening the darker portions or saturating the brighter portions of the image in the next frame.

A progressive scan display system comprising:

• a signal receiving unit;
• a tuner box for transforming the signal into an analog signal;
• a video decoder for transforming the analog signal into a plurality of interlaced video fields, wherein each video field comprises a plurality of pixels and each pixel is defined by a luminance value and chrominance data based on color differences;
• a de-interlacing system for converting the interlaced video fields into a progressive video signal;
• an image controller for adjusting the pixel data of the video signal, the image controller comprising:
• an image brightness and contrast management module for automatically adjusting the luminance data of the video signal to suit a viewer's tastes, the module comprising:
• a histogram generation unit for generating, on a frame-by-frame basis, a pixel luminance histogram based on a luminance value of each of a plurality of pixels in a frame, wherein the histogram comprises a distribution of luminance values in the frame, the distribution indicating a dynamic range and at least one dominant luminance value for the frame;
• a histogram characterization unit for analyzing the pixel luminance histogram for the frame and for identifying which of a plurality of brightness/contrast properties is exhibited in the frame;
• and
• a brightness and contrast adjustment unit for nonlinearly adjusting in real-time the luminance values of the plurality of pixels in a next frame based on the identified brightness/contrast properties exhibited in a preceding frame;
• and
• a display for displaying the adjusted progressive video signal.