Motion vector detecting apparatus for video telephone/teleconference systems

• US 5,142,361 A
• Filed: 06/19/1991
• Issued: 08/25/1992
• Est. Priority Date: 06/21/1990
• Status: Expired due to Fees

• Current Assignee: Graphics Communication Technologies Limited
• Original Assignee: Graphics Communication Technologies Limited
• Inventors: Tayama, Masashi, Fujiwara, Hiroshi, Maruyama, Masanori
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US07/717,894
• Time in Patent Office: 433 Days
• Field of Search: 358/105, 358/136, 358/133, 358/140, 358/85
• US Class Current: 348/416.1
• CPC Class Codes: G06F 12/0862 with prefetch
• CPC Class Codes: G06F 12/0875 with dedicated cache, e.g. instruction or stack
• CPC Class Codes: G06F 12/0897 with two or more cache hierarchy levels with multilevel cache hierarchies G06F12/0811
• CPC Class Codes: G06T 7/238 using non-full search, e.g. three-step search

Abstract

A motion vector detecting apparatus for detecting motion vectors based on a current frame data and the preceding frame data. In the motion vector detecting apparatus, first and second memories are provided in order to store the current frame data and the preceding frame data. Additionally, a number of first cache memories, a number of second cache memories, a control circuit, and a motion vector calculation circuit are provided. The control circuit selects the input cache memories into which pixel data are to be written, and the output cache memories, from which pixel data are to be read out, from the first and second cache memories, so that the input cache memories and the output cache memories have no redundant cache memory. Pixel data corresponding to the detection image blocks stored in the first memory and pixel data corresponding to the search image blocks stored in the second memory are sequentially written in the selected input cache memories of the first and second cache memories. Simultaneously, the pixel data corresponding to the detection image blocks and the search image blocks are sequentially read out from the selected output cache memories, and are sequentially supplied to the motion vector calculation circuit.

Claims

1. A motion vector detecting apparatrus for detecting motion vectors based on current frame data including a number of pixel data and preceding frame data which had been immediately previously entered thereto, said motion vector detecting apparatus comprising:

first storing means for storing said current frame data;

second storing means for storing said preceding frame data;

first temporary storing means for storing pixel data supplied from said first storing means, said first temporary storing means having a number of a cache memories;

a number of second temporary storing means for storing pixel data supplied from said second storing means, said second temporary storing means having a number of cache memories;

acces control means for controlling read and write operations of said first and second storing means and said first and second temporary storing means, said access control means performing a first transfer operation, in which cache memories of said first and second temporary storing means are sequentially selected as input cache memories into which pixel are to be written, and pixel data corresponding to detection image blocks included in said current frame data and pixel data corresponding to neighboring image blocks included in said preceding frame data are transferred respectively from said first and second storing means respectively to the selected input cache memories of said first and second temporary storing means, said access control means further performing a second transfer operation, in which cache memories of said first and second temporary storing means, into which writing is not being conducted, are sequentially selected as output cache memories, from which pixel data are to be read out, and pixel data corresponding to said detection image blocks stored in the selected output cache memories of said first temporary storing means and pixel data corresponding to said neighboring image blocks stored in the selected output cache memories of said second temporary storing means are sequentially read out; and

motion vector calculation means for sequentially evaluating the correlation between pixel data read out from said first temporary storing means and pixel data read out from said second temporary storing means, and for detecting said motion vector based on an image block read out from said second temporary means which has the highest correlation.

2. A motion vector detecting apparatus according to claim 1, wherein said motion vector calculation means includes a number of motion vector calculation circuits,

whereby said pixel data are alternatively supplied to said motion vector calculation circuits, and motion vectors are calculated by said motion vector calculation circuits in a parallel manner.

3. A motion vector detecting apparatus according to claim 1, wherein a search range surrounding said detection image block is defined, and said second temporary storing means has cache memories for storing pixel data of image blocks included in said search range.