System for processing video signals

• US 4,375,650 A
• Filed: 04/29/1981
• Issued: 03/01/1983
• Est. Priority Date: 04/29/1981
• Status: Expired due to Fees

• Current Assignee: Television Analog Compression Corporation
• Original Assignee: General Electric Company
• Inventors: Tiemann, Jerome J.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Coles, Edward L.
• Application Number:
  US06/258,856
• Time in Patent Office: 671 Days
• Field of Search: 358/133, 358/260, 358/138, 358/135, 358/136, 340/347 DD, 364/515, 364/725, 364/726
• US Class Current: 375/240.2
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/60 using transform coding

Abstract

A video processing system in which each field of image data is divided into rows and columns of blocks of picture elements. The number of blocks utilized is large enough so that when each block is considered to be a picture element, the blocks provide a reasonable raster for the peripheral vision aspect of the human visual perception system. The blocks of picture elements are transformed into blocks of spatial frequency components. The zero and low spatial frequency components of the blocks of spatial frequency transforms are updated at a sufficiently rapid rate to satisfy the requirements of the peripheral vision aspect of the human perception system. The higher spatial frequency components of the blocks of spatial frequency are updated at a lower rate corresponding to the rate at which the human perception system can respond to such information.

Claims

1. In combination,

means for providing a video signal having a plurality of first sequences of values, each value of a first sequence derived from the intensity of a respective element of a picture, said picture having a plurality of elements mappable into rows and columns thereof, said picture being segmented into a plurality of identical blocks of elements, each block having rows and columns of elements, each block of elements represented by a respective set of subsequences of said first sequence of values,

means for transforming each of said first sequences into a respective second sequence of values, said transformation including transforming each set of subsequences of a first sequence corresponding to a block of picture elements into a respective set of spatial frequency components of a respective block thereof, each block of spatial frequency components including rows representing different values of vertical spatial frequency ranging from low to high values of spatial frequency, and columns representing different values of horizontal spatial frequency ranging from the low to high values of spatial frequency, each component being a unique combination of a row and a column spatial frequency, said block of components being segmented into several groups of components, each group including components of a different range of spatial frequency values, the group including the component with both spatial frequency values equal to zero being designated the first group and the group including the component with the largest sum of spatial frequency values being designated the last group, said groups of components including different numbers of components, the first group including the smallest number of components and at least one of the other groups having the largest number of components, each second sequence including a series of sets of components, each set of a second sequence including a predetermined number of spatial frequency components from each of said groups arranged in a predetermined order within and among said groups, correspondingly ordered spatial frequency components from said sets of a second sequence having the same spatial frequency values, sets of components of successive second sequences having successively different combinations of spatial frequency components in accordance with a predetermined schedule, a predetermined number of successive second sequences equal to the number of components in the largest of said groups constituting a supersequence, successive supersequences representing successive pluralities of successive pictures corresponding to a scene.

2. The combination of claim 1 in which said predetermined number of spatial frequency components from said last group included in said sets of said second sequences is zero, and in which a supersequence is constituted of a predetermined number of successive second sequences equal to the number of components in the largest of said groups excluding the last of said group.

3. The combination of claim 1 including a storage medium and means for storing each of said values of said second sequences of said supersequences in said storage medium.

4. The combination of claim 3 including means for recovering each of said values of said second sequences of said supersequences from said storage medium,

a memory including a plurality of storage locations,

means for storing the value of each of the components included in said supersequences of said second sequences in a respective memory location of said memory corresponding to the spatial frequency values thereof, whereby during any one supersequence all of the values of the components of each of the groups of each of said blocks of spatial frequency components are stored at least once, and the components of the groups of said blocks of spatial frequency components other than the components of the largest of said groups thereof are updated several times during the period of a supersequence,

means for retrieving each block of components stored in said memory,

means for obtaining the inverse transform of each retrieved block of components to obtain a set of subsequences of values corresponding to the intensity of elements of a respective block of elements of a picture,

means for assemblying said sets of subsequences of values to obtain a sequence of values corresponding to said first sequence of values.

5. The combination of claim 1 including a transmission channel,

means for transmitting said second sequences over said transmission channel,

means for receiving each of said second sequences from said transmission channel,

a memory including a plurality of storage locations,

means for storing the value of each of the components included in said supersequences of said second sequences in a respective memory location of said memory corresponding to the spatial frequency values thereof, whereby during any one supersequence all of the values of the components of each of the groups of each of said blocks of spatial frequency components are stored at least once, and the components of the groups of said blocks of spatial frequency components other than the components of the largest of said groups thereof are updated several times during the period of a supersequence,

means for retrieving each block of components stored in said memory,

means for obtaining the inverse transform of each retrieved block of components to obtain a set of subsequences of values corresponding to the intensity of elements of a respective block of elements of a picture,

means for assembling said sets of subsequences of values to obtain a sequence of values corresponding to said first sequence of values.

6. The combination of claim 1 in which the values of said second sequences are in the form of binary words.

7. The combination of claim 6 in which the words of the components of the group having the smallest number of components include the largest number of bits and the words of the components of the group having the largest number of components include the smallest number of bits.

8. The combination of claim 1 in which each of said blocks of components of spatial frequencies is a discrete cosine transform of a respective block of picture elements.

9. The combination of claim 1 in which each of said blocks of components of spatial frequencies is a Walsh-Hadamard transform of a respective block of picture elements.

10. The combination of claim 1 in which each of said blocks of components of spatial frequencies is a Fourier transform of a respective block of picture elements.

11. The combination of claim 4 in which the operation of said means for retrieving and said means for transforming each block of components to obtain a respective set of subsequence of values, and said means for assemblying said sets of subsequences of values into a first sequence of values occurs over an interval relatively short in relation to the period of a supersequence.

12. The combination of claim 4 including means programmed in accordance with said predetermined order and said predetermined schedule to direct each of said components of said second sequences to a respective preassigned storage location in said memory.

13. The combination of claim 5 in which the operation of said means for accessing and said means for transforming each block of components to obtain a respective set of subsequences of values, and said means for assemblying said sets of subsequences of values into a first sequence of values occurs over an interval relatively short in relation to the period of a supersequence.

14. The combination of claim 5 including means programmed in accordance with said predetermined order and said predetermined schedule to direct each of said components of said second sequences to a respective preassigned storage location in said memory.