Video compression system

• US 20050025248A1
• Filed: 07/30/2003
• Published: 02/03/2005
• Est. Priority Date: 07/30/2003
• Status: Active Grant

• Current Assignee: Vertiv IT Systems, Inc. (Vertiv Holdings Co.)
• Original Assignee: Avocent Corporation (Vertiv Holdings Co.)
• Inventors: Johnson, Timothy A., Blackwell, Steven R.
• Granted Patent: US 9,560,371 B2
• Time in Patent Office: Days
• US Class Current: 375/240.240
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/503 involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• CPC Class Codes: H04N 19/507 using conditional replenishment

Abstract

A improvement to video compression techniques is described in which blocks of video input information are compared in their respective pixel values to corresponding blocks of immediately preceding frames. The blocks are analyzed to determine whether change has occurred in accordance with two tests. First, the pixel values of the block are compared to the pixel values of a preceding block and if a threshold number of pixel values in the block exceed their counterparts by a threshold amount, then the block is assumed to have changed and is communicated via a standard communication protocol, compression technique and media. Second, even if the threshold number of pixels in the block has not changed, the pixel values are compared with their prior frame counterparts to determine if any one pixel value has changed in magnitude more than a second threshold amount. Again, one such pixel is identified, then the block is assumed to have changed and is communicated.

Claims

1. A method of communicating video information as the video information changes from one frame to another, comprising:

a. analyzing pixel values within a current block of the video frame information to determine pixel value frame change;

b. testing;

(i) whether a frame change in pixel value for any one of the pixels in the block exceeds a first threshold, and

(ii) whether a second threshold number of pixels in the block exceeds in pixel value a third threshold, and

c. if the conditions of either step b. i. or step b. ii. exceed the thresholds described, then communicating information identifying the pixel values within the block.

2. A method according to claim 1, further comprising:

d. if both conditions of steps b. i. and b. ii. fail to exceed the thresholds described, then communicating a no change condition in the current block.

3. A method according to claim 2, wherein:

the communicated no change condition comprises communicating nothing regarding the current block; and

decoding the video information by writing current blocks for which nothing is communicated as unchanged compared to a corresponding block in a previous frame.