Spatio-temporal adaptive video de-interlacing

A method comprising:

• storing fourteen pixel values, including:
• (a) a second pixel value which is in a current video signal field and corresponds to a pixel location that is immediately above a location of a current pixel to be interpolated;
• (b) a first pixel value which is in the current video signal field and corresponds to a pixel location immediately to the left of the location of the second pixel value;
• (c) a third pixel value which is in the current video signal field and corresponds to a pixel location immediately to the right of the location of the second pixel value;
• (d) a fifth pixel value which is in the current video signal field and corresponds to a pixel location immediately below the location of the current pixel to be interpolated;
• (e) a fourth pixel value which is in the current video signal field and corresponds to a pixel location immediately to the left of the location of the fifth pixel value;
• (f) a sixth pixel value which is in the current video signal field and corresponds to a pixel location immediately to the right of the location of the fifth pixel value;
• (g) a ninth pixel value which is in a preceding video signal field which immediately precedes said current video signal field, said ninth pixel value corresponding in location to said current pixel to be interpolated;
• (h) an eighth pixel value which is in the preceding video signal field and which corresponds to a pixel location immediately to the left of the location of the ninth pixel value;
• (i) a seventh pixel value which is in the preceding video signal field and which corresponds to a pixel location immediately to the left of the location of the eighth pixel value;
• (j) a tenth pixel value which is in the preceding video signal field and which corresponds to a pixel location immediately to the right of the location of the ninth pixel value;
• (k) an eleventh pixel value which is in the preceding video signal field and which corresponds to a pixel location immediately to the right of the location of the tenth pixel value;
• (l) a thirteenth pixel value which is in a succeeding video signal field which immediately succeeds said current video signal field, said thirteenth pixel value corresponding in location to said current pixel to be interpolated;
• (m) a twelfth pixel value which is in the succeeding video signal field and which corresponds to a pixel location immediately to the left of the location of the thirteenth pixel value;
• and
• (n) a fourteenth pixel value which is in the succeeding video signal field and which corresponds to a pixel location immediately to the right of the location of the thirteenth pixel value;
• deriving an interpolated value of said current pixel to be interpolated from application of a median function to said first through six stored pixel values if an absolute value of a difference between said ninth and thirteenth stored pixel values exceeds or is equal to a first threshold;
• deriving the interpolated value of said current pixel to be interpolated from application of said median function to a provisional pixel value, said second stored pixel value and said fifth stored pixel value if the absolute value of the difference between said ninth and thirteenth stored pixel values is less than said first threshold;
• deriving said provisional pixel value from application of the median function to said second, fifth, ninth and thirteenth stored pixel values if an absolute value of a difference between said eighth and twelfth stored pixel values is less than a second threshold and an absolute value of a difference between said tenth and fourteenth stored pixel values is less than a third threshold;
• deriving said provisional pixel value from application of said median function to said first, fourth, seventh and eighth stored pixel values if said absolute value of said difference between said eighth and twelfth pixel values is less than said second threshold and said absolute value of said difference between said tenth and fourteenth pixel values is not less than said third threshold;
• deriving said provisional pixel value from application of said median function to said third, sixth, tenth and eleventh stored pixel values if said absolute value of said difference between said eighth and twelfth stored pixel values is not less than said second threshold and said absolute value of said difference between said tenth and fourteenth stored pixel values is less than said third threshold;
• and
• deriving said provisional pixel value from application of said median function to said first through sixth stored pixel values if said absolute value of said difference between said eighth and twelfth stored pixel values is not less than said second threshold and said absolute value of said difference between said tenth and fourteenth stored pixel values is not less than said third threshold.

An apparatus comprising:

• a storage medium having stored thereon instructions that when executed by a machine result in the following:
• storing a current field of a digital video signal;
• storing a preceding field that immediately precedes the current field in the digital video signal;
• storing a succeeding field that immediately succeeds the current field in the digital video signal;
• examining the preceding and succeeding fields for motion at a locus of a current pixel to be interpolated;
• and
• if any motion at said locus is less than a threshold, examining the preceding and succeeding fields for motion at a respective locus of at least one pixel that is adjacent to said current pixel to be interpolated.

A method comprising:

• storing a current field of a digital video signal;
• storing a preceding field that immediately precedes the current field in the digital video signal;
• storing a succeeding field that immediately succeeds the current field in the digital video signal;
• examining the preceding and succeeding fields for motion at a locus of a current pixel to be interpolated;
• and
• comparing a first difference between a pixel value in one of said preceding and succeeding fields and an interpolated pixel value for said current field for a pixel location immediately to the left of said current pixel to be interpolated with a second difference between said pixel value in one of said preceding and succeeding fields and a pixel value in said current field for a pixel location that is either immediately above or immediately below said current pixel to be interpolated.

A system comprising:

• a tuner;
• and
• a de-interlacing circuit coupled to the tuner and operative to:
• store a current field of a digital video signal;
• store a preceding field that immediately precedes the current field in the digital video signal;
• store a succeeding field that immediately succeeds the current field in the digital video signal;
• examine the preceding and succeeding fields for motion at a locus of a current pixel to be interpolated;
• and
• if any motion at said locus is less than a threshold, examine the preceding and succeeding fields for motion at a respective locus of at least one pixel that is adjacent to said current pixel to be interpolated.