Motion vector detecting apparatus and method and distribution medium

• US 6,519,353 B1
• Filed: 08/26/1999
• Issued: 02/11/2003
• Est. Priority Date: 08/28/1998
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ogura, Eiji
• Primary Examiner(s): Patel, Jayanti K.
• Application Number:
  US09/383,770
• Time in Patent Office: 1,265 Days
• Field of Search: 382/100, 382/107, 382/154, 382/232, 382/236, 382/240, 382/305-307, 341/67, 345/419, 345/501, 348/208, 348/169, 348/394.1, 348/699, 375/240, 375/240.16, 708/203, 383/232, 358/140
• US Class Current: 382/107
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/20052 Discrete cosine transform [DCT]
• CPC Class Codes: G06T 7/223 using block-matching
• CPC Class Codes: H04N 19/557 Motion estimation characterised by stopping computation or iteration based on certain criteria, e.g. error magnitude being too large or early exit
• CPC Class Codes: H04N 19/57 Motion estimation characterised by a search window with variable size or shape

Abstract

A motion vector detecting circuit calculates a residual between the reference block read from a frame memory and retrieving block at the predetermined position of a retrieving frame to output to an operation control circuit. The operation control circuit discriminates whether a residual value supplied from the motion vector detecting circuit is larger than the threshold value Th1 and the threshold value Th2 which is smaller than Th1 or not respectively and controls the vector detecting circuit corresponding to such discrimination result. When the residual value is larger than the threshold value Th1, the motion vector detecting circuit instructs execution of the motion vector detecting process utilizing the comparatively wider retrieving range. When the residual value is less then the threshold value Th1 and is larger than the threshold value Th2, the motion vector circuit instructs execution of the motion vector detecting process utilizing the comparatively narrower retrieving range. Moreover, when the residual value E is less than the threshold value Th2, the motion vector detecting circuit instructs stop of execution of the motion vector detecting process. As explained above, the motion vector detecting process can be executed corresponding to the input image data.

Claims

1. A motion vector detecting apparatus for detecting a motion vector to compensate for movement when encoding input image data, comprising:

a first motion vector detecting circuit for extracting a retrieving block from a current frame of the input image data on the basis of a retrieving range, and calculating a residual value between the retrieving block and a reference block from a reference frame of the input image data;

an operation control circuit for adjusting the retrieving range by comparing the residual value calculated by the first motion vector detecting circuit to a first threshold value and a second threshold value;

the first threshold value being greater than said second threshold value; and

a second motion vector detecting circuit for detecting a motion vector for said current frame on the basis of the adjusted retrieving range from said operation control circuit, and outputting said motion vector to a motion compensating circuit.

2. The motion vector detecting apparatus according to claim 1, wherein the operation control circuit increases the retrieving range when the residual value is greater than said first threshold value;

decreases the retrieving range when the residual value is less than said first threshold value and greater than said second threshold value; and

stops operation of the second motion vector detecting circuit when the residual value is less than said second threshold value.

3. A motion vector detecting method of detecting a motion vector to compensate for movement when encoding input image data, comprising the steps of:

extracting a retrieving block from a current frame of the input image data on the basis of a retrieving range;

calculating a residual value between the retrieving block and a reference block from a reference frame of the input image data;

adjusting the retrieving range by comparing the residual value to a first threshold value and a second threshold value;

the first threshold value being greater than said second threshold value; and

detecting a motion vector for said current frame on the basis of the adjusted retrieving range and outputting said motion vector to a motion compensating circuit.

4. The motion vector detecting method according to claim 3, wherein the adjusting step increases the retrieving range when the residual value is greater than said first threshold value;

decreases the retrieving range when the residual value is less than said first threshold value and greater than said second threshold value; and

stops operation of the detecting step when the residual value is less than said second threshold value.