Method and system using sequentially encoded color and luminance processing of video type signals to improve picture quality

A method of converting sequentially encoded color and luminance (SECAL) video type signals to standard composite video signals having a predetermined overall temporal length and an active signal portion of predetermined temporal length less than the overall length, said SECAL video type signals having luminance and chrominance components re-formatted as compressed video lines of reduced bandwidth, each line containing a pair of groups of video signals, one of said pair of groups containing compressed luminance samples, the other of said pair of groups containing compressed chrominance samples, said groups being compressed in accordance with a predetermined compression ratio and the temporal length of that portion of each compressed re-formatted video line containing said groups being less than said overall temporal length and greater than said active signal portion temporal length, said method comprising the steps of:

• (a) providing said SECAL video type signals;
• (b) generating a first clock signal having a first frequency;
• (c) sampling said SECAL video type signals with said first clock signal;
• (d) temporarily storing the SECAL samples in a storage device;
• (e) generating second and third clock signals having second and third frequencies, the ratio of said second and third frequencies being equal to said predetermined compression ratio and said first frequency being higher than said second frequency;
• (f) sequentially reading the SECAL luminance group samples corresponding to a given line from said storage device with said second clock signals while contemporaneously sequentially reading the SECAL chrominance group samples corresponding to the same line from said storage device with said third clock signals;
• and
• (g) assembling the contemporaneously read SECAL luminance and chrominance samples into said composite video signals, the relative number of luminance samples and chrominance samples produced by said first clock signal and the frequency of said second and third clock signals being selected so that the temporal length of the portion of each line of composite video signals assembled from said SECAL luminance and chrominance samples is substantially equal to the temporal length of said active portion.

A system for re-formatting video type line sequential signals having luminance components and chrominance components, each line of said line sequential signals having a predetermined overall temporal length and an active signal portion of predetermined temporal length less than the overall length, said system comprising:

• input terminal means for receiving said luminance components and said chrominance components;
• means for generating first and second clock signals having frequencies f and f/N, respectively, where N is a finite non-zero value;
• means coupled to said input terminal means and said generating means for sampling and storing said luminance components and said chrominance components with said first and second sampling clock signals, respectively;
• means for generating a third clock signal having a frequency higher than said first clock signal frequency;
• and
• means coupled to said sampling means and said third clock signal generating means for serially arranging the sampled and stored component samples on a line-by-line basis to form compressed re-formatted video lines each containing a pair of groups of samples, one of said pair of groups containing luminance samples, the other of said pair of groups containing chrominance samples, said groups being compressed in accordance with a predetermined ratio equal to said value N, said arranging means including means for first reading one of said pair of groups of samples from said sampling and storing means with said third clock signals and then reading the other one of said pair of groups of samples from said sampling and storing means with said third clock signals, the relative number of luminance samples and chrominance samples and the frequency of said third clock signals being selected so that the temporal length of each compressed re-formatted video line is less than said overall temporal length and greater than said active signal portion temporal length.

A system for processing sequentially encoded color and luminance (SECAL) video type signals corresponding to original standard composite video signals having a predetermined overall temporal length and an active signal portion of predetermined temporal length less than the overall length, said SECAL video type signals having luminance and chrominance components re-formatted as compressed video lines of reduced bandwidth, each line containing a pair of contiguous groups of video signals, one of said pair of groups containing compressed luminance samples, the other of said pair of groups containing compressed chrominance samples, said groups being compressed in accordance with a predetermined compression ratio and the temporal length of that portion of each compressed re-formatted video line containing said groups being less than said overall temporal length and greater than said active signal portion temporal length, said system comprising:

• input terminal means for receiving said re-formatted video type signals;
• means for generating a first clock signal having a first frequency;
• means coupled to said input terminal means and said generating means for sampling and storing said re-formatted lines with said first clock signals;
• means for generating second and third clock signals having second and third frequencies, the ratio of said second and third frequencies being equal to said predetermined compression ratio and said first frequency being higher than said second frequency;
• and
• means for converting the sampled groups to successive lines of standard composite video signals, said converting means including means for sequentially reading the SECAL luminance group samples corresponding to a given line from said sampling and storing means with said second clock signals while contemporaneously sequentially reading the SECAL chrominance group samples corresponding to the same line from said sampling and storing means with said third clock signals;
• and
• means for assembling the contemporaneously read SECAL luminance and chrominance samples into said composite video signals, the relative number of luminance samples and chrominance samples produced by said first clock signal and the frequency of said second and third clock signals being selected so that the temporal length of the portion of each line of composite video signals assembled from said SECAL luminance and chrominance samples is substantially equal to the temporal length of said active portion.

A method for processing video type line sequential signals having luminance components and chrominance components to reduce the bandwidth thereof, each line of said line sequential signals having a predetermined overall temporal length and an active signal portion of predetermined temporal length less than said overall length, said method comprising the steps of:

• (a) generating first and second sampling clock signals having frequencies f and f/N, respectively, where N is a finite non-zero value;
• (b) sampling said luminance and said chrominance components with said first and second clock signals, respectively;
• (c) temporarily storing the component samples in a storage device;
• (d) generating a third clock signal having a frequency higher than said first clock signal frequency;
• (e) serially arranging the temporarily stored component samples on a line-by-line basis to form compressed re-formatted sequentially encoded color and luminance (SECAL) video lines each containing a pair of groups of samples, one of said pair of groups containing luminance samples, the other of said pair of groups containing chrominance samples, said groups being compressed in accordance with a predetermined ratio equal to said value N, said step of serially arranging including the step of first outputting one of said pair of groups of samples under control of said third clock signal and then outputting the other one of said pair of groups of samples under control of said third clock signal, the relative number of luminance samples and chrominance samples and the frequency of said third clock signal being selected so that the temporal length of that portion of each compressed re-formatted video line containing said groups is less than said overall temporal length and greater than said active signal portion temporal length;
• (f) providing said re-formatted SECAL video line signals to a subsequent processing device;
• (g) generating a fourth clock signal having a fourth frequency;
• (h) sampling said SECAL video type signals with said fourth clock signal;
• (i) temporarily storing the SECAL samples in a storage device;
• (j) generating fifth and sixth clock signals having fifth and sixth frequencies, the ratio of said fifth and sixth frequencies being equal to N and said fourth frequency being higher than said fifth frequency;
• (k) sequentially reading the SECAL luminance group samples corresponding to a given line from said storage device with said fifth clock signals while contemporaneously sequentially reading the SECAL chrominance group samples corresponding to the same line from said storage device with said sixth clock signals;
• and
• (l) reassembling the contemporaneously read SECAL luminance and chrominance samples into the original composite video signal format, the relative number of luminance samples and chrominance samples produced by said fourth clock signal and the frequency of said fifth and sixth clock signals being selected so that the temporal length of the portion of each line of composite video signals reassembled from said SECAL luminance and chrominance samples is substantially equal to the temporal length of said active portion of the original composite video signals.