Motion compensation estimating device and method achieving improved motion compensation

• US 5,572,258 A
• Filed: 09/20/1994
• Issued: 11/05/1996
• Est. Priority Date: 09/28/1993
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Yokoyama, Yutaka
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): Au, A.
• Application Number:
  US08/309,083
• Time in Patent Office: 777 Days
• Field of Search: 348/402, 348/413, 348/416, 348/420, 348/699, 348/700, 348/701, 382/107, 382/173, 382/236
• US Class Current: 348/415.1
• CPC Class Codes: H04N 19/20 using video object coding
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation

Abstract

An area subdividing unit subdivides a reference image, producing sub-areas. An inter-frame difference calculating device determines inter-frame differences between the reference image and an input image. A moving area detecting unit designates, by reference to the inter-frame differences, moving areas from a plurality of sub-areas. An area integrating device integrates the detected moving areas according to information of the reference image to create a plurality of moving object areas. A motion estimating device estimates motion between the input and reference images for each moving object area to attain motion parameters. A motion compensating unit compensates motion for each moving object area based on the motion parameters to generate a motion compensated prediction image. A motion compensating apparatus is capable of achieving complete and exact motion compensation using area information and a reduced number of encoding operations.

Claims

1. A motion compensation apparatus for inter-frame prediction comprising:

an area subdividing means for subdividing a reference image into sub-areas and producing a subdivided area,

an inter-frame difference calculating means for producing inter-frame difference information between an input image and the reference image;

a moving area detecting means for detecting, by reference to the inter-frame difference information, sub-areas in said subdivided area having inter-frame difference information of a predetermined character and designating said sub-areas as moving areas;

an area integrating means for integrating the moving areas and outputting the integrated areas as moving object areas;

motion estimating means for estimating inter-frame motion between the input and reference images for each of the moving object areas and outputting motion parameters representing motion of the moving object areas; and

motion compensating means for conducting motion compensation for each of the moving object areas according to the motion parameters and producing and outputting a motion compensated prediction image.

2. A motion compensation apparatus as claimed in claim 1, wherein the area subdividing means subdivides the reference image into sub-areas using at least one of a region growing method, a dividing method, a split and merge method, and a clustering method.

3. A motion compensation apparatus as claimed in claim 1, wherein the moving area detecting means checks a plurality of sub-areas and designates as moving areas sub-areas having large inter-frame differences.

4. A motion compensation apparatus as claimed in claim 1, wherein the area integrating means integrates adjacent moving areas having similar characteristics equal to or more than a predetermined value.

5. A motion compensation;

apparatus as claimed in claim 1, wherein the motion estimating means establishes, by use of the moving object areas as templates, matching with respect to a current frame image and thus attains motion parameters.

6. A motion compensation apparatus as claimed in claim 1, wherein the motion compensating means initializes the motion compensated prediction image to predetermined values and overwrites the predetermined values with values corresponding to a displaced and transformed image of the moving object areas.

7. A motion compensation method of inter-frame prediction comprising the steps of:

subdividing a reference image into sub-areas and producing a subdivided area;

producing inter-frame difference information between an input image and the reference image;

detecting, by reference to the inter-frame difference information, sub-areas of the subdivided area having inter-frame difference information of a predetermined character and designating said sub-areas as moving areas;

integrating the moving areas and outputting the integrated areas as moving object areas;

estimating inter-frame motion between the input and reference images for each of the moving object areas and outputting motion parameters representing motion of the moving object areas; and

conducting motion compensation for each of the moving object areas according to the motion parameters and producing and outputting a motion compensated prediction image.

8. A motion compensation method as claimed in claim 7, wherein the area subdividing step subdivides the reference image into, sub-areas using at least one of a region growing method, a dividing method, a split and merge method, method, and a clustering method.

9. A motion compensation method as claimed in claim 7, wherein the moving area detecting step checks a plurality of sub-areas and designates as moving areas sub-areas having large inter-frame differences.

10. A motion compensation method as claimed in claim 7, wherein the area integrating step integrates adjacent moving areas having similar characteristics equal to or more than a predetermined value.

11. A motion compensation method as claimed in claim 7, wherein the motion estimating step establishes, by use of the mobile object areas as templates, matching with respect to a current frame image and thus attains motion parameters.

12. A motion compensation method as claimed in claim 7, wherein the motion compensating step initializes the motion compensation estimated image to predetermined values and overwrites the predetermined values with values corresponding to a displaced and transformed image of the moving object areas.