System for estimating motion vector with instant estimation of motion vector

• US 6,148,108 A
• Filed: 01/15/1998
• Issued: 11/14/2000
• Est. Priority Date: 01/16/1997
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nishikawa, Tsuyoshi
• Primary Examiner(s): Tran, Phuoc
• Assistant Examiner(s): Mariam, Daniel G.
• Application Number:
  US09/007,603
• Time in Patent Office: 1,034 Days
• Field of Search: 382/236, 382/253, 382/238, 382/232, 348/416, 348/699, 348/402, 348/413
• US Class Current: 382/236
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments
• CPC Class Codes: H04N 19/527 Global motion vector estimation
• CPC Class Codes: H04N 19/54 using feature points or meshes
• CPC Class Codes: H04N 5/145 Movement estimation for video coding H04N19/51

Abstract

A motion vector estimating system comprises a current image storing unit 1, a reference image storing unit 2, a motion vector estimating circuit 3 for estimating a motion of a current image in relation to a reference image, and a global motion vector estimating circuit 10. The global motion vector estimating circuit 10 comprises at least a feature setting part 11 for setting and recording a feature being a partial region distinguishable from other regions of a principle object in a picture, a feature-coordinates extracting part 12 for searching the current image for the feature to extract the coordinates of the feature, and a feature-coordinates storing part 13 for storing the coordinates of the feature. When the feature-coordinates extracting part 12 extracts the coordinates of the feature from the current image, the motion vector estimating system derives a difference between the feature coordinates stored in the storing part 13 and the extracted feature coordinates on the basis of a feature presence information outputted from the feature-coordinates extracting part 12, in order to estimate a global motion vector. When the feature-coordinates extracting part 12 has not could extract the feature, the motion vector estimating system carries out the usual motion vector estimation. Thus, in addition to the usual motion vector estimation, the presence and coordinates of a feature are extracted from the whole screen of a picture to detect a motion vector to retrieve a correct motion vector at the initial stage of the retrieval, so that it is possible to save the electric power and decrease the estimation time.

Claims

1. A motion vector estimating system comprising:

current image storing means for storing a current image being an inputted moving picture information;

reference image storing means for storing a reference image information;

a motion vector estimating circuit for estimating a motion in the current image stored in the current image storing means, in relation to the reference image stored in the reference image storing means; and

a global motion vector estimating circuit including;

feature setting means for setting and storing a feature being a partial region distinguishable from other regions of a principle object in a picture,

feature-coordinates extracting means for searching the current image stored in the current image storing means, for the feature stored in the feature setting means, to identify the position of the feature on a coordinate as feature coordinates, and

feature-coordinates storing means for storing the feature coordinates extracted by the feature-coordinates extracting means,

wherein said motion vector estimating circuit derives a difference between the feature coordinates stored in said feature-coordinates storing means and the feature coordinates extracted by said feature-coordinates extracting means on the basis of a feature presence information outputted from said feature-coordinates extracting means, to estimate a global motion vector, when said feature-coordinates extracting means extracts the coordinates of the feature, which has been set by said feature setting means, from said current image.

2. A motion vector estimating system as set forth in claim 1, wherein said global motion vector estimating circuit comprises:

a feature describing circuit, serving as said feature setting means, for describing said feature;

a feature-coordinates extracting circuit for extracting said feature from a screen of the current image supplied from a current image frame memory serving as said current image storing means, to output the presence and coordinates of said feature in the screen;

a feature-coordinates information buffer for temporarily storing the feature coordinates outputted from said feature-coordinates extracting circuit; and

a last picture feature-coordinates information buffer for storing the feature of the last current image, which has been stored, when the feature coordinates of the present current image is outputted to said feature-coordinates storing buffer.

3. A motion vector estimating system as set forth in claim 2, wherein said feature describing circuit for describing a predetermined shape of marker serving as said feature on the picture of said principal object at an optional position is provided in said global motion vector estimating circuit, and which further comprises:

a current image pixel-position correction circuit for correcting the coordinates of a picture element when reading said current image information out of said current image frame memory on the basis of correction information on a feature-position fixing outputted from said global motion vector estimating circuit in a case where a feature-position fixing request signal supplied from the outside is active, to output a feature presence information representative of the presence of said feature in the current image; and

a marker erasing circuit for erasing said marker described by said feature describing circuit from the picture on the basis of the coordinates information outputted from said global motion vector estimating circuit and the feature presence information outputted from said current image pixel-position correction circuit.

4. A motion vector estimating system as set forth in claim 2, wherein said motion vector estimating circuit is provided in a moving picture processing unit, which carries out the image processing of the current image supplied from said current image frame memory using a motion vector information of each macro block serving as a unit obtained by dividing said current image into partial regions, said feature presence information and said feature coordinates information, and which carries out the image processing in the case of no motion vector when a motion vector estimation stopping signal for stopping the estimation of a motion vector for each of macro blocks is active.

5. A motion vector estimating system as set forth in claim 4, wherein said moving picture processing unit is provided in a MPEG2 encoder for processing a moving picture in accordance with the standard of MPEG2, which is a standard defined by a moving picture expert group.

6. A motion vector estimating system as set forth in claim 1, which further comprises a feature describing circuit for describing a marker being a specific picture serving as a feature set on said principal object at an optional position, and feature-coordinates extracting means having storing means for storing the feature of said specific picture, and

said motion vector estimating system extracting the feature of said principal object from the whole region of a picture frame or field to extract global coordinates of the feature of the principal object to measure the movement of the characteristic point of the principal object between frames or fields to derive said global motion vector of said principal object.

7. A motion vector estimating system as set forth in claim 1, which further comprises stopping means for stopping the estimating operation of a motion vector with respect to a macro block serving as each of partial regions of a divided screen when the magnitude of said global motion vector of said principal object is unsuitable for a moving picture compression standard.

8. A motion vector estimating system as set forth in claim 7, wherein a motion vector close to the global motion vector is preferentially calculated in said macro block serving as each of partial regions of the divided screen.