Automatic control of visual parameters in video processing

Abstract

Embodiments of the invention are directed to a system and method for controlling visual parameters of a capturing device. The method includes analyzing a current frame of a received video signal captured by a capturing device and automatically adjusting visual parameters of the capturing device for a subsequent frame in a feedback process based on analysis of the current frame. The adjustment may reduce clipping and saturation in the subsequent frame.

1 . A method comprising:
 analyzing a current frame of a received video signal captured by a capturing device; and   automatically adjusting visual parameters of the capturing device for a subsequent frame in a feedback process based on analysis of the current frame.   
     
     
         2 . The method of  claim 1 , wherein adjusting the visual parameters is to reduce clipping and saturation in the subsequent frame. 
     
     
         3 . The method of  claim 1 , wherein the capturing device includes an analog-to-digital converter (ADC). 
     
     
         4 . The method of  claim 1 , wherein the capturing device is an Internet Protocol (IP) camera, a digital video recorder or a network encoder. 
     
     
         5 . The method of  claim 1 , wherein analyzing comprises processing only pixel values of a specific region of the current frame and adjusting the visual parameters of the capturing device is based on analysis of the specific region. 
     
     
         6 . The method of  claim 1 , wherein analyzing the current frame comprises:
 processing pixel values for the current frame;   generating an accumulated histogram using the pixel values of the current frame together with pixel values of one or more previous input frames;   calculating a desired dynamic range based on predetermined user parameters; and   checking if the accumulated histogram is within the desired dynamic range and determining if adjustment is desired   
     
     
         7 . The method of  claim 6 , wherein the predetermined user setting parameters are based on user preferences. 
     
     
         8 . The method of  claim 6 , further comprising:
 determining whether a scene has been changed between the current frame and a previous frame and if so performing a reset operation.   
     
     
         9 . The method of  claim 6 , further comprising:
 calculating a calculated low-clipping threshold and a calculated high-saturation threshold based on the accumulated histogram;   determining a desired low sensitivity area and a desired high sensitivity area for the desired dynamic range; and   identifying a location of the calculated low-clipping threshold relative to the desired low sensitivity area and a location of the calculated high-saturation threshold relative to the desired high sensitivity area.   
     
     
         10 . A system comprising:
 a capturing device to capture a current frame of a video signal;   a frame receiver to receive a digital representation of the current frame from the capturing device;   a frame calculator to process pixel values of the current frame and to generate an accumulated histogram for the pixel values of the current frame together with pixel values of one or more previous input frames;   a frame analyzer to calculate a desired dynamic range based on predetermined user parameters and to determine if the accumulated histogram is within the desired dynamic range; and   a controller to automatically adjust visual parameters of the capturing device for a subsequent frame in a feedback process based on analysis of the current frame.   
     
     
         11 . The system of  claim 10 , further comprising:
 a memory unit to store the predetermined parameters.   
     
     
         12 . The system of  claim 10 , wherein the frame analyzer is to determine a desired low-sensitivity area and a desired high-sensitivity area, to calculate, based on the accumulated histogram, a calculated low-clipping threshold and a calculated high-saturation threshold and to determine if the accumulated histogram is within the desired dynamic range by identifying a location of the calculated low-clipping threshold relative to the desired low-sensitivity area and the location of the calculated high-saturation threshold relative to the desired high-sensitivity area.