Image processing apparatus and method, and recording medium and program used therewith

• US 20050259739A1
• Filed: 04/08/2005
• Published: 11/24/2005
• Est. Priority Date: 04/09/2004
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kaino, Akihiko, Kawaguchi, Kunio, Nakamura, Yukihiro, Takahashi, Yasuaki, Yoshiwara, Norifumi, Horishi, Takashi, Choki, Yuta
• Granted Patent: US 7,738,556 B2
• Time in Patent Office: Days
• US Class Current: 375/240.160
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/20021 Dividing image into blocks, subimages or windows
• CPC Class Codes: G06T 3/4007 based on interpolation, e.g. bilinear interpolation image demosaicing G06T3/4015; edge-driven or edge-based scaling G06T3/403
• CPC Class Codes: G06T 7/238 using non-full search, e.g. three-step search
• CPC Class Codes: H04N 5/145 Movement estimation for video coding H04N19/51
• CPC Class Codes: H04N 7/014 involving the use of motion vectors motion estimation and compensation in video coding H04N19/51

Abstract

A past frame at a past time has a motion vector in a block, and a reference frame at a reference time has a different block which is a motion-compensated block identical in position to a terminal point of a motion vector in the block. When a gradient method is used to detect a motion vector in the different block in the reference frame, a motion vector which is identical in magnitude and orientation to a motion vector and whose initial point is the different block in the reference frame is used as a candidate vector for initial vectors. The present invention is applicable to a signal processing apparatus for performing frame frequency conversion from a 24P signal to a 60P signal.

Claims

1. An image processing apparatus comprising:

initial vector selecting means for selecting an initial vector used as an initial value for a gradient method for detecting a motion vector in a block of interest in a present frame;

motion vector detecting means for using the gradient method to detect the motion vector in the block of interest by using the initial vector selected by said initial vector selecting means;

shifted initial vector setting means for setting, as a shifted initial vector, a shifted motion vector having an initial point at the block of interest in said present frame being identical in position to a terminal point of the motion vector detected by said motion vector detecting means in a past frame with respect to said present frame; and

candidate vector setting means for setting the shifted initial vector set by said shifted initial vector setting means as one of candidate vectors for selecting the initial vector in the block of interest by said initial vector selecting means; and

wherein said shifted motion vector is identical in magnitude and in orientation to the motion vector detected by said motion vector detecting means.

2. The image signal processing apparatus according to claim 1,

wherein said motion vector is a motion vector having an initial point at said block of interest in said present frame, and said initial vector selecting means selects an initial vector having an initial point at said block of interest in said present frame.

3. The image processing apparatus according to claim 1, wherein said shifted initial vector setting means comprises:

block operation means for finding the block in said present frame identical in position to the terminal block at the terminal point of the motion vector detected by said motion vector detecting means;

reliability comparing means for comparing, in the block found by said block operation means, reliabilities of the motion vector detected by said motion vector detecting means; and

shifted initial vector selecting means for selecting, as the shifted initial vector for a block in said present frame, a motion vector identical in magnitude and orientation to one motion vector determined by said reliability comparing means to have a highest reliability.

4. The image processing apparatus according to claim 1, wherein, in said candidate vector setting means, the shifted initial vector set by said shifted initial vector setting means in the block of interest, and the motion vector detected by said motion vector detecting means, motion vectors in a predetermined peripheral block around the block of interest, detected in said present frame or said past frame, are set as candidate vectors for selecting the initial vector.

5. The image processing apparatus according to claim 1, further comprising evaluated value operation means for calculating evaluated values representing reliabilities of the candidate vectors set by said candidate vector setting means,

wherein said initial vector selecting means selects the initial vector for the block of interest in said present frame based on the evaluated values in said past frame calculated by said evaluated value operation means.

6. The image processing apparatus according to claim 1, further comprising:

allocating means for allocating the motion vector detected by said motion vector detecting means to pixels in an interpolated frame between the frames; and

pixel-value interpolation generating means for performing interpolation to generate the values of the pixels in the interpolated frame based on the motion vector allocated by said allocating means.

7. An image processing method comprising:

an initial vector selecting step of selecting an initial vector used as an initial value for a gradient method for detecting a motion vector in a block of interest in a present frame;

a motion vector detecting step of using the gradient method to detect the motion vector in the block of interest by using the initial vector selected in the initial vector selecting step;

a shifted initial vector setting step of setting, as a shifted initial vector, a shifted motion vector having an initial point at the block of interest in said present frame being identical in position to a terminal point of the motion vector detected in the motion vector detecting step in a past frame with respect to said present frame; and

a candidate vector setting step of setting the shifted initial vector set in the shifted initial vector setting step as one of candidate vectors for selecting the initial vector in the block of interest in the initial vector selecting step,

wherein said shifted motion vector is identical in magnitude and in orientation to the motion vector detected in said motion vector detecting step.

8. A recording medium having a program recorded thereon, the program comprising:

an initial vector selecting step of selecting an initial vector used as an initial value for a gradient method for detecting a motion vector in a block of interest in a present frame;

a motion vector detecting step of using the gradient method to detect the motion vector in the block of interest by using the initial vector selected in the initial vector selecting step;

a shifted initial vector setting step of setting, as a shifted initial vector, a shifted motion vector having an initial point at the block of interest in said present frame being identical in position to a terminal point of the motion vector detected in the motion vector detecting step in a past frame with respect to said present frame; and

a candidate vector setting step of setting the shifted initial vector set in the shifted initial vector setting step as one of candidate vectors for selecting the initial vectors in the block of interest in the initial vector selecting step,

wherein said shifted motion vector is identical in magnitude and in orientation to the motion vector detected by said motion vector detecting step.

9. A program for allowing a computer to perform processing, the program comprising:

an initial vector selecting step of selecting an initial vector used as an initial value for a gradient method for detecting a motion vector in a block of interest in a present frame;

a motion vector detecting step of using the gradient method to detect the motion vector in the block of interest by using the initial vector selected in the initial vector selecting step;

a shifted initial vector setting step of setting, as a shifted initial vector, a shifted motion vector having an initial point at the block of interest in said present frame being identical in position to a terminal point of the motion vector detected in the motion vector detecting step in a past frame with respect to present said frame; and

a candidate vector setting step of setting the shifted initial vector set in the shifted initial vector setting step as one of candidate vectors for selecting the initial vector in the block of interest in the initial vector selecting step,

wherein said shifted motion vector is identical in magnitude and in orientation to the motion vector detected by said motion vector detecting step.

10. An image processing apparatus comprising:

an initial vector selector configured to select an initial vector used as an initial value for a gradient method for detecting a motion vector in a block of interest in a present frame;

a motion vector detector configured to use the gradient method to detect the motion vector in the block of interest by using the initial vector selected by said initial vector selector;

a shifted initial vector setting unit configured to set, as a shifted initial vector, a shifted motion vector having an initial point at the block of interest in said present frame being identical in position to a terminal point of the motion vector detected by said motion vector detector in a past frame with respect to said present frame; and

a candidate vector setting unit configured to set the shifted initial vector set by said shifted initial vector setting device as one of candidate vectors for selecting the initial vector in the block of interest by said initial vector selector; and

wherein said shifted motion vector is identical in magnitude and in orientation to the motion vector detected by said motion vector detector.