Content-Dependent Scan Rate Converter with Adaptive Noise Reduction

Abstract

A content-dependent scan rate converter with adaptive noise reduction that provides a highly integrated, implementation efficient de-interlacer. By identifying and using redundant information from the image (motion values and edge directions), this scan rate converter is able to perform the tasks of film-mode detection, motion-adaptive scan rate conversion, and content-dependent video noise reduction. Adaptive video noise reduction is incorporated in the process where temporal noise reduction is performed on the still parts of the image, thus preserving high detail spatial information, and data-adaptive spatial noise reduction is performed on the moving parts of the image. A low-pass filter is used in flat fields to smooth out Gaussian noise and a direction-dependent median filter is used in the presence of impulsive noise or an edge. Therefore, the selected spatial filter is optimized for the particular pixel that is being processed to maintain crisp edges.

1 - 33 . (canceled) 
     
     
         34 . A scan converter comprising:
 an impulse noise filter;   a Gaussian noise filter; and   an adaptive noise filter capable of temporally filtering data with low motion content and spatial filtering on data with motion content above a threshold.   
     
     
         35 . The scan converter of  claim 34 , wherein a low-pass filter is used in flat fields to reduce Gaussian noise. 
     
     
         36 . The scan converter of  claim 34 , wherein a median filter is used to reduce impulse noise. 
     
     
         37 . The scan converter of  claim 34 , wherein a direction-dependent median filter is used to reduce impulse noise. 
     
     
         38 . The scan converter of  claim 34 , wherein a median filter is used to filter image data representing image edges. 
     
     
         39 . The scan converter of  claim 34 , wherein a direction-dependent median filter is used to filter image data representing image edges.