Television system for transmitting pictures in a digital form

• US 5,970,207 A
• Filed: 05/01/1995
• Issued: 10/19/1999
• Est. Priority Date: 07/07/1992
• Status: Expired due to Term

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Brondijk, Robert A., De With, Peter H. N., Bruls, Wilhelmus H. A., Nijssen, Stephanus J. J.
• Primary Examiner(s): NGUYEN, HUY THANH
• Application Number:
  US08/431,877
• Time in Patent Office: 1,632 Days
• Field of Search: 386/111, 386/46, 386/112, 386/109, 386/124, 386/98, 348/423, 348/390, 348/420, 360/32, 360/48
• US Class Current: 386/329
• CPC Class Codes: G11B 20/12 Formatting, e.g. arrangement of data block or words on the record carriers within interface between computers and data recorders G06F3/06
• CPC Class Codes: H04N 11/044 involving transform coding
• CPC Class Codes: H04N 5/9264 using transform coding
• CPC Class Codes: H04N 9/8047 using transform coding

Abstract

To be able to transmit television pictures in a digital form through a medium having a limited bandwidth, the pictures are subjected to picture transform and to variable-length coding. The picture to be transmitted is converted in this manner into a bit stream comprising code words of variable length. This bit stream is converted into a channel bit stream which is less sensitive to transmission errors. To this end the most significant code words (representing the average luminance and the coarse picture details) of sub-pictures of 8*8 pixels are accommodated at fixed bit positions of the channel bit stream. These code words can be retrieved by simple count-down of the bit positions. The other code words are distributed over the other bit positions. The decoder is relatively simple because the length of each block comprising significant code words is also transmitted. This length is preferably adapted to the extent of picture detail in the sub-picture.

Claims

1. A storage medium on which a picture signal is stored in the form of a digital data stream comprising a series of data blocks comprising code words of variable length, each data block having a variable length and being divided into a main block having a variable length and comprising only selected code words and a sub-block having a variable length and comprising other code words, the digital data stream comprising:

a series of one or more of the main blocks at each one of a plurality of predetermined first bit positions of the digital data stream;

at a predetermined position within each of said main block, a length code which is indicative of the length of said each main block; and

sub-blocks corresponding to each said series of main blocks at remaining bit positions of the digital data stream,

whereby decoding of code words and/or End Of Block code detection are not needed to distinguish between said main blocks and said sub-blocks.

2. A storage medium as claimed in claim 1 wherein the selected code words in each said main block are most significant code words in a corresponding data block and wherein the other code words in each of said sub-blocks are least significant code words in said corresponding data block.

3. A storage medium in which a picture signal, represented as a series of data blocks comprising code words of variable length, is stored in a coded format, the coded format comprising:

a sequential series of channel blocks located at predetermined positions within the storage medium, a series of one or more contiguous main blocks being stored at a fixed predetermined storage position within each said of channel blocks, each of said main blocks comprising selected code words of a different one of said data blocks and one or more dummy bits, a length code indicative of the length of each said main block being stored at a fixed predetermined position within each said main block, and sub-blocks comprising other code words of the data blocks being stored in remaining storage positions of the channel blocks, whereby decoding of code words and/or End Of Block code detection are not needed to distinguish between said main blocks and said sub-blocks.

4. A storage medium as claimed in claim 3 wherein the selected code words in each said main block are most significant code words in a corresponding data block and wherein the other code words in each of said sub-block are least significant code words in said corresponding data block.

5. A storage medium in which a picture signal is stored in a predetermined format, the picture signal comprising a series of data blocks, each of said data block comprising code words of variable length, each said data block being divided into a main block of a variable length comprising selected code words of most significance and a sub-block of a variable length comprising other code words of least significance, the predetermined format comprising a sequential series of channel blocks, each of said channel blocks having a beginning bit located at a predetermined position within the storage medium, a plurality of the main blocks being stored adjacent to each other and at a predetermined position within said storage medium determined by said beginning bit of said each channel block, a length code indicative of the length of each of said main blocks being stored at a fixed predetermined position within each said main block, and the code words of the sub-blocks being stored at remaining positions of said channel blocks, whereby decoding of code words and/or End Of Block code detection are not needed to distinguish between said main blocks and said sub-blocks.

6. A storage medium in which a picture signal is stored in a predetermined format, the picture signal comprising a series of data blocks, each of said data blocks comprising code words of variable length, each said data block being divided into a main block of a variable length comprising selected code words of most significance and a sub-block of a variable length comprising other code words of least significance, the predetermined format comprising a sequential series of channel-blocks, each of said channel blocks having a beginning bit located at a predetermined position within the storage medium, each of the main blocks being stored in a different one of said channel blocks and at a predetermined position within said storage medium relative to said beginning bit of said different one of said channel blocks, a length code indicative of the length of each said main block being stored at a fixed predetermined position within each said main block, and the code words of the sub-blocks being stored at remaining positions of said channel blocks, whereby decoding of code words and/or End Of Block code detection are not needed to distinguish between said main blocks and said sub-blocks.