Detection And Repair Of MPEG-2 Chroma Upconversion Artifacts

Abstract

A method for removing MPEG-2 chroma upconversion artifacts in a video stream includes detecting a presence of artifacts in an incorrectly upsampled MPEG-2 video stream and removing the presence of artifacts resulting in an artifact free video stream.

1 . A video system for producing a corrected progressive MPEG-2 output from an MPEG-2 compressed video source, the video system comprising: 
 a) a source input for receiving an MPEG-2 compressed video signal from an external MPEG-2 compressed video source;    b) a progressive MPEG-2 decoder having a decoder input adapted to receive the progressive MPEG-2 compressed video signal from the MPEG-2 compressed video source;    c) a buffer having a buffer input coupled to an output of the progressive MPEG-2 decoder; and    d) a video processing module having a processing module input coupled to an output of the buffer generating an output signal for coupling with an external progressive display, the external progressive display being adapted for receiving the generated output signal and for providing a display of the signal in response to the receipt.    
     
     
         2 . The video system as in  claim 1 , further comprising: the external progressive display having the input coupled to the output of the video processing module.  
     
     
         3 . The video system as in  claim 1 , further comprising: the external MPEG-2 compressed video source.  
     
     
         4 . The video system as in  claim 1 , wherein said video processing module includes a video processing module that performs an operation for the detection and repair of MPEG-2 chroma up conversion artifacts.  
     
     
         5 . The video system as in  claim 1 , wherein said video processing module performing detection and repair of MPEG-2 chroma up conversion artifacts by: detecting a presence of artifacts in an incorrectly up sampled MPEG-2 video stream based on a difference between even line and odd line frequency detection values of the video stream; and removing the presence of artifacts resulting in an artifact free video stream.  
     
     
         6 . A method for producing a corrected progressive MPEG-2 output from an MPEG-2 compressed video source, the method comprising: 
 a) receiving an MPEG-2 compressed video signal from an MPEG-2 compressed video source;    b) decoding the received MPEG-2 compressed video signal by applying a progressive MPEG-2 decoder operation to generate a decoded output signal;    c) storing the generated decoded output signal in a buffer as it is generated; and    d) performing a video processing operation on the buffered decoded output signal to generate an output signal for coupling with an external progressive display, the external progressive display being adapted for receiving the generated output signal and for providing a display of the signal in response to the receipt.    
     
     
         7 . The method as in  claim 6 , wherein the performing the video processing operation comprises an operation for the detection and repair of MPEG-2 chroma up conversion artifacts.  
     
     
         8 . The method as in  claim 7 , wherein the performing detection and repair of MPEG-2 chroma up conversion artifacts comprises: 
 detecting a presence of artifacts in an incorrectly up sampled MPEG-2 video stream based on a difference between even line and odd line frequency detection values of the video stream; and    removing the presence of artifacts resulting in an artifact free video stream.    
     
     
         9 . The method as in  claim 7 , wherein the performing detection and repair of MPEG-2 chroma up conversion artifacts comprises: 
 detecting a presence of artifacts in an incorrectly up sampled MPEG-2 video stream, comprising the steps of:    obtaining a first set of frequency detection values for a chroma component of a plurality of pixels from a plurality of even numbered rows;    obtaining a first set of vertically low pass filtered frequency detection values for a chroma component of a plurality of pixels from a plurality of even numbered rows;    obtaining a second set of frequency detection values for a chroma component of a plurality of pixels from a plurality of odd numbered rows;    obtaining a second set of vertically low pass filtered frequency detection values for a chroma component of a plurality of pixels from a plurality of odd numbered rows;    calculating a first sum of an absolute value of the first set of frequency detection values;    calculating a first sum of an absolute value of the first set of vertically low pass filtered frequency detection values;    calculating a second sum of an absolute value of the second set of frequency detection values;    calculating a second sum of an absolute value of the second set of vertically low pass filtered frequency detection values;    calculating a first absolute value difference between the first sum of the absolute value of the first set of frequency detection values and the second sum of the absolute value of the second set of frequency detection values;    calculating a second absolute value difference between the first sum of the absolute value of the first set of vertically low pass filtered frequency detection values and the a second sum of an absolute value of the second set of vertically low pass filtered frequency detection values; and    confirming the presence of artifacts if a ratio between the first absolute value difference and the second absolute value difference is larger than about a threshold; and    removing the presence of artifacts resulting in an artifact free video stream.    
     
     
         10 . The method as in  claim 9 , wherein the first and second sets of frequency detection values and the first and second sets of low pass filtered frequency detection values are obtained by performing a partial discrete Fourier transform on a set of vertically aligned chroma data samples.  
     
     
         11 . The method as in  claim 7 , wherein the performing detection and repair of MPEG-2 chroma up conversion artifacts comprises: 
 determining a difference between even line and odd line frequency detection values of the video stream;    detecting a presence of artifacts in an up sampled video stream based on a the determined difference; and    removing the presence of artifacts resulting in an artifact free video stream.    
     
     
         12 . The method in  claim 11 , wherein the detecting a presence of artifacts further comprises: 
 calculating a first sum of an absolute value of a first set of frequency detection values and a second sum of an absolute value of a first set of vertically low pass filtered frequency detection values for a chroma component of a plurality of pixels from a plurality of even numbered rows;    calculating a third sum of an absolute value of a second set of frequency detection values and a fourth sum of an absolute value of a second set of vertically low pass filtered frequency detection values for a chroma component of a plurality of pixels from a plurality of odd numbered rows;    calculating a first absolute value difference between the first sum and the third sum and a second absolute value difference between the second sum and the a fourth sum; and    confirming the presence of artifacts if a ratio between the first absolute value difference and the second absolute value is within a magnitude relationship of an identified threshold.    
     
     
         13 . A video system for producing a corrected progressive MPEG-2 output from an MPEG-2 compressed interlaced video source comprising: 
 a) an MPEG-2 compressed video source;    b) an interlaced MPEG-2 decoder having an input coupled to an output of the MPEG-2 compressed video source;    c) a deinterlacer having an input coupled to an output of the interlaced MPEG-2 decoder;    d) a buffer having an input coupled to an output of the deinterlacer; and    e) a video processing module having an input coupled to an output of the buffer.    
     
     
         14 . A video system as in  claim 13 , further comprising: 
 f) a progressive display having an input coupled to an output of the video processing module.    
     
     
         15 . The video system as in  claim 13 , wherein said video processing module includes a video processing module that performs an operation for the detection and repair of MPEG-2 chroma up conversion artifacts.  
     
     
         16 . The video system as in  claim 13 , wherein said video processing module performing detection and repair of MPEG-2 chroma up conversion artifacts by: detecting a presence of artifacts in an incorrectly up sampled MPEG-2 video stream based on a difference between even line and odd line frequency detection values of the video stream; and removing the presence of artifacts resulting in an artifact free video stream.  
     
     
         17 . The video system as in  claim 13 , wherein the performing the video processing operation comprises an operation for the detection and repair of MPEG-2 chroma up conversion artifacts and a deinterlacer.  
     
     
         18 . A video system for producing a corrected progressive MPEG-2 output from an MPEG-2 compressed video source comprising: 
 a) an MPEG-2 compressed video source;    b) an interlaced MPEG-2 decoder having an input for receiving an MPEG-2 compressed video stream;    c) a buffer having an input coupled to an output of the interlaced MPEG-2 decoder for storing the decoded MPEG-2 video data; and    d) a deinterlacer/video processing module having an input coupled to an output of the buffer for receiving the buffered decoded MPEG-2 video data and for generating a processed output.    
     
     
         19 . A video system as in  claim 18 , further comprising: 
 e) a progressive display having an input coupled to the output of the deinterlacer/video processing module.    
     
     
         20 . The video system as in  claim 18 , wherein said video processing module includes a video processing module that performs an operation for the detection and repair of MPEG-2 chroma up conversion artifacts.  
     
     
         21 . The video system as in  claim 18 , wherein said video processing module performing detection and repair of MPEG-2 chroma up conversion artifacts by: detecting a presence of artifacts in an incorrectly up sampled MPEG-2 video stream based on a difference between even line and odd line frequency detection values of the video stream; and removing the presence of artifacts resulting in an artifact free video stream.  
     
     
         22 . The method as in  claim 18 , wherein the performing the video processing operation comprises an operation for the detection and repair of MPEG-2 chroma up conversion artifacts and a deinterlacer.  
     
     
         23 . A single combined processing module for a video signal or data, the processing module including: 
 a video deinterlacing operation; and    a detection and repair of MPEG-2 chroma up conversion artifacts, wherein the detecting and repairing of a presence of artifacts in an incorrectly up sampled MPEG-2 video stream based on a difference between even line and odd line frequency detection values of the video stream, and removing the presence of artifacts resulting in an artifact free video stream;    the combined processing module incurring at least one frame of video less delay in operation as compared to separate video deinterlacing and detection and repair of MPEG-2 chroma up-conversion artifacts.