Temporal vector processing device and method for motion estimation

• US 20100283900A1
• Filed: 12/08/2009
• Published: 11/11/2010
• Est. Priority Date: 05/11/2009
• Status: Active Grant

• Current Assignee: Sunplus Technology Co., Ltd
• Original Assignee: Sunplus Technology Co., Ltd
• Inventors: Chen, Yen-Lin, Peng, Yuan-Chih
• Granted Patent: US 8,355,446 B2
• Time in Patent Office: Days
• US Class Current: 348/699
• CPC Class Codes: H04N 19/43 Hardware specially adapted for motion estimation or compensation
• CPC Class Codes: H04N 19/533 Motion estimation using multistep search, e.g. 2D-log search or one-at-a-time search [OTS]
• CPC Class Codes: H04N 19/553 Motion estimation dealing with occlusions
• CPC Class Codes: H04N 5/145 Movement estimation for video coding H04N19/51

Abstract

A temporal vector processing device includes a motion vector estimation device for performing a motion estimation on a first pixel to generate a first motion vector. A motion vector compensation device performs a motion vector compensation on the first pixel based on the first motion vector to obtain a second pixel. A buffer temporarily stores motion vectors of the pixels of the image. A motion vector determination device determines whether a second motion vector is stored in the buffer at a corresponding storage location of the second pixel. In determining that the second motion vector is stored in the buffer at the corresponding storage location of the second pixel, the corresponding storage location of the second pixel in the buffer is updated based on a determination mechanism, and otherwise the first motion vector is directly stored in the buffer at the corresponding storage location of the second pixel.

Claims

1. A temporal vector processing method for motion estimation, which adjusts a temporal vector corresponding to a pixel of an image consisting of a 2D array of pixels, the method comprising the steps of:

(A) resetting a buffer stored therein motion vectors of the pixels of the image;

(B) performing a motion vector estimation on a first pixel read from the image to generate a first motion vector;

(C) performing a motion vector compensation on the first pixel according to the first motion vector to generate a second pixel;

(D) determining whether a second motion vector is stored in a corresponding storage location of the second pixel in the buffer stores;

(E) directly storing the first motion vector in the buffer at the corresponding storage location of the second pixel when it is determined that the buffer does not store the second motion vector in step (D), and executing step (G);

(F) updating the motion vector stored in the buffer at the corresponding storage location of the second pixel according to a determination mechanism when it is determined that the buffer stores the second motion vector in step (D), and executing step (G); and

(G) returning to step (B) for processing a next pixel succeeding the first pixel.

2. The temporal vector processing method as claimed in claim 1, wherein the motion vector compensation in step (C) performs a displacement on the first pixel to generate the second pixel, wherein a displacement quantity is equal to the first motion vector.

3. The temporal vector processing method as claimed in claim 2, wherein the determination mechanism comprises the steps of:

calculating an absolute value of a difference between the first motion vector and a global motion vector to generate a first difference absolute value, and calculating an absolute value of a difference between the second motion vector and the global motion vector to generate a second difference absolute value;

storing the first motion vector in the buffer at the corresponding storage location of the second pixel when the first difference absolute value is greater than the second difference absolute value; and

storing the second motion vector in the buffer at the corresponding storage location of the second pixel when the first difference absolute value is smaller than or equal to the second difference absolute value.

4. The temporal vector processing method as claimed in claim 2, wherein the determination mechanism comprises the steps of:

calculating an absolute value of a difference between the first motion vector and the second motion vector to generate a third difference absolute value;

selecting a smaller one from the first motion vector and the second motion vector when the third difference absolute value is smaller than a threshold, and storing the smaller one in the buffer at the corresponding storage location of the second pixel; and

storing a cover flag in the buffer at the corresponding storage location of the second pixel when the third difference absolute value is greater than or equal to the threshold.

5. A temporal vector processing device for motion estimation, which adjusts a temporal vector corresponding to a pixel of an image consisting of a 2D array of pixels, the temporal vector processing device comprising:

a motion vector estimation device for performing a motion estimation on a first pixel read from the image to generate a first motion vector;

a motion vector compensation device connected to the motion vector estimation device for performing a motion vector compensation on the first pixel based on the first motion vector to generate a second pixel;

a buffer connected to the motion vector compensation device for storing motion vectors of the pixels of the image; and

a motion vector determination device connected to the motion vector estimation device and the buffer for determining whether a corresponding storage location of the second pixel in the buffer stores a second motion vector, wherein the second motion vector stored in the buffer at the corresponding storage location of the second pixel is updated according to a determination mechanism when it is determined that the second motion vector is stored in the buffer, otherwise the first motion vector is directly stored in the buffer at the corresponding storage location of the second pixel.

6. The temporal vector processing device as claimed in claim 5, further comprising a frame buffer connected to the buffer for temporarily storing the motion vectors in the buffer and store the motion vectors after the motion vectors corresponding to the storage location of the second pixel in the buffer are no more updated.

7. The temporal vector processing device as claimed in claim 6, wherein the motion vector compensation device performs a displacement on the first pixel to generate the second pixel, where a displacement quantity is equal to the first motion vector.

8. The temporal vector processing device as claimed in claim 7, wherein the motion vector determination device comprises:

a first subtractor for subtracting the first motion vector from a global motion vector to generate a first difference;

a second subtractor for subtracting the second motion vector from the global motion vector to generate a second difference;

a first absolute value generator connected to the first subtractor for performing an absolute operation on the first difference to generate a first difference absolute value;

a second absolute value generator connected to the second subtractor for performing an absolute operation on the second difference to generate a second difference absolute value;

a first comparator connected to the first and the second absolute value generators for generating a first comparison signal; and

a first multiplexer connected to the first comparator for receiving the first and the second motion vectors, wherein the first motion vector is outputted when the first comparison signal is at a high voltage and conversely the second motion vector is outputted.

9. The temporal vector processing device as claimed in claim 7, wherein the motion vector determination device comprises:

a third subtractor for subtracting the first motion vector from the second motion vector to generate a third difference;

a third absolute value generator connected to the third subtractor for performing an absolute operation on the third difference to generate a third difference absolute value;

a second comparator connected to the third absolute value generator for generating a second comparison signal at a low voltage when the third difference absolute value is smaller than a threshold and generating the second comparison signal at a high voltage when the third difference absolute value is greater than or equal to the threshold;

a minimum generator for receiving the first and the second motion vectors and outputting a smaller one therebetween as a smaller motion vector; and

a second multiplexer connected to the second comparator and the minimum generator for receiving the smaller motion vector and a cover flag, wherein the cover flag is outputted when the second comparison signal is at the high voltage and conversely the smaller motion vector is outputted.