Method of motion detection for 3D comb filter video decoder

• US 7,432,987 B2
• Filed: 03/30/2004
• Issued: 10/07/2008
• Est. Priority Date: 12/22/2003
• Status: Expired due to Fees

• Current Assignee: Sunplus Technology Co., Ltd
• Original Assignee: Sunplus Technology Co., Ltd
• Inventors: Shan, Pei-Ming, Peng, Uriah
• Primary Examiner(s): Yenke, Brian P.
• Application Number:
  US10/708,875
• Publication Number:
  US 20050134744A1
• Time in Patent Office: 1,652 Days
• Field of Search: 348/451, 348/663, 348/665, 348667-670, 348699-701
• US Class Current: 348/667
• CPC Class Codes: H04N 9/78 for separating the brightness signal or the chrominance signal from the colour television signal, e.g. using comb filter

Abstract

A method of motion detection for a 3D comb filter video decoder is disclosed. In this method, a plurality of sampled data F_mP_x,y is obtained and temporarily stored after a composite video signal is sampled, wherein F_mP_x,y represents a sampled data of the y^th pixel on the x^th line of the m^th frame inside the composite video signal, and m, x, y are positive integers greater than or equal to 0. Then, F_m+1P_x,y, F_mP_x,y, F_m−1P_x,y, and F_m−2P_x,y are used to determine a motion/still status of the composite video signal. Since the present invention performs the motion detection according to the composite video signal whose Y/C has not been separated yet, the present invention can accurately determine the motion level.

Claims

1. A method of motion detection for a 3D comb filter video decoder, comprising:

sampling a composite video signal for obtaining a plurality of temporarily stored sampled data F_mP_x,y, wherein F_mP_x,y represents a sampled data of a y^th pixel on an x^th line of an m^th frame in the composite video signal, and m, x, y are positive integers greater than or equal to 0, wherein the composite video signal is a signal for a PAL system, a frequency which is 4 times the subcarrier frequency in the composite video signal is used to sample the composite video signal, and the composite video signal is sampled when the subcarrier phase is equal to 0.25π

, 0.75π

, 1.25π

, and 1.75π

; and

using F_m+1P_x,y, F_mP_x,y, F<sub>m−

1</sub>P_x,y, and F<sub>m−

2</sub>P_x,y to determine a motion/still status of the composite video signal, comprising;

using F_m+1P_x,y, F_mP_x,y, F<sub>m−

1</sub>P_x,y, and F<sub>m−

2</sub>P_x,y to calculate and obtain a plurality of max differences MD_x,y, wherein MD_x,y represents a max difference of the y^th pixel on the x^th line;

averaging 4 max differences of the contiguous pixels selected to obtain a motion factor MF_x,y, wherein MF_x,y represents a motion factor of the y^th pixel on the x^th line; and

detecting MF_x,y to determine the motion/still status of the y^th pixel on the x^th line in the composite video signal,

wherein the step of calculating and obtaining MD_x,y further comprises;

calculating and obtaining a plurality of luma differences LD_x,y, wherein LD_x,y represents a luma difference of the y^th pixel on the x^th line, and is calculated based on an equation;

LD_x,y=|F_mP_x,y+F<sub>m−

2</sub>P_x,y−

F_m+1P_x,y−

F<sub>m−

1</sub>P_x,y|;

calculating and obtaining a plurality of intermediate differences IMD_x,y, wherein IMD_x,y represents an intermediate difference of the y^th pixel on the x^th line, and is calculated based on an equation;

IMD<sub>i,2j−

1</sub>=Max{|F_m+1P<sub>i,2j−

1</sub>−

F<sub>m−

2</sub>P<sub>i,2j−

1</sub>|, |F_mP<sub>i,2j−

1</sub>−

F<sub>m−

1</sub>P<sub>i,2j−

1</sub>|};

IMD_i,2j=Max{|F_m+1P_i,2j−

F_mP_i,2j|, |F<sub>m−

1</sub>P_i,2j−

F<sub>m−

2</sub>P_i,2j|}; and

calculating and obtaining MD_x,y, which is calculated based on an equation;

MD_x,y=a*IMD_x,y+(1−

a)*LD_x,y;

wherein, a is a real number greater than 0 and less than 1, and i, j are positive integers.

2. A method of motion detection for a 3D comb filter video decoder, comprising:

sampling a composite video signal for obtaining a plurality of temporarily stored sampled data F_mP_x,y, wherein F_mP_x,y represents a sampled data of a y^th pixel on an x^th line of an m^th frame in the composite video signal, and m, x, y are positive integers greater than or equal to 0; and

using F_m+1P_x,y, F_mP_x,y, F<sub>m−

1</sub>P_x,y, and F<sub>m−

2</sub>P_x,y to determine a motion/still status of the composite video signal, comprising;

using F_m+1P_x,y, F_mP_x,y, F<sub>m−

1</sub>P_x,y, and F<sub>m−

2</sub>P_x,y to calculate and obtain a plurality of max differences MD_x,y, wherein MD_x,y represents a max difference of the y^th pixel on the x^th line;

averaging 4 max differences of the contiguous pixels selected to obtain a motion factor MF_x,y, wherein MF_x,y represents a motion factor of the y^th pixel on the x^th line; and

detecting MF_x,y to determine the motion/still status of the y^th pixel on the x^th line in the composite video signal,

wherein the step of obtaining MF_x,y further comprises;

averaging 4 max differences of the contiguous pixels selected to obtain a plurality of max differences AMD_x,h, wherein AMD_x,h represents an average of max difference of a h^th pixel on the x^th line, h is a positive integer, and AMD_x,h is calculated based on an equation;

AMD_x,h=(MD_x,h+MD_x,h+1+MD_x,h+2+MD_x,h+3)/4; and

selecting a minimum from the averages of max difference to obtain a motion factor MF_x,y, wherein MF_x,y represents a motion factor of the y^th pixel on the x^th line,

wherein the step of selecting a minimum from the averages of max difference to obtain MF_x,y is based on an equation;

MF_x,y=Min(AMD_x,y, AMD<sub>x,y−

1</sub>, AMD<sub>x,y−

2</sub>, AMD<sub>x,y−

3</sub>), and

wherein the step of selecting a minimum from the averages of max difference to obtain MF_x,y is based on an equation;

MF_x,y=Min(AMD_x,y, AMD<sub>x,y−

3</sub>).

3. A method of motion detection for a 3D comb filter video decoder, comprising:

sampling a composite video signal to obtain a sampled data F_m+1P_x,y, wherein F_m+1P_x,y represents a sampled data of a y^th pixel on an x^th line of an (m+1)^th frame in the composite video signal, and m, x, y are positive integers greater than or equal to 0, wherein the composite video signal is a signal for an NTSC system, and sampling the composite video signal uses a frequency which is 4 times the subcarrier frequency in the composite video signal to sample; and

obtaining three stored sampled data F_mP_x,y, F<sub>m−

1</sub>P_x,y, F<sub>m−

2</sub>P_x,y, previously sequentially sampled directly from the composite video signal and stored in a storing means, wherein the sampled data F_m+1P_x,y and the three previously sequentially sampled data F_mP_x,y, F<sub>m−

1</sub>P_x,y, F<sub>m−

2</sub>P_x,y are obtained by directly sampling the composite video signal when the subcarrier phase is equal to 0, 0.5π

, π

, and 1.5π

, sequentially;

using the sampled data F_m+1P_x,y and the three stored sampled data F_mP_x,y, F<sub>m−

1</sub>P_x,y, F<sub>m−

2</sub>P_x,y to determine a motion/still status of the composite video signal, comprising;

using F_m+1P_x,y, F_mP_x,y, F<sub>m−

1</sub>P_x,y, and F<sub>m−

2</sub>P_x,y to calculate and obtain a plurality of max differences MD_x,y, wherein MD_x,y represents a max difference of the y^th pixel on the x^th line;

averaging 4 max differences of the contiguous pixels selected to obtain a motion factor MF_x,y, wherein MF_x,y represents a motion factor of the y^th pixel on the x^th line; and

detecting MF_x,y to determine the motion/still status of the y^th pixel on the x^th line in the composite video signal.

4. The method of motion detection for a 3D comb filter video decoder of claim 3, wherein MD_x,y is calculated based on an equation:

MD_x,y=Max{|F_mP_x,y−

F<sub>m−

2</sub>P_x,y|, |F_m+1P_x,y−

F<sub>m−

1</sub>P_x,y|}.

5. The method of motion detection for a 3D comb filter video decoder of claim 3, wherein the step of detecting MF_x,y to determine the motion/still status of the y^th pixel on the x^th line in the composite video signal further comprises:

providing a threshold; and

comparing MF_x,y with the threshold, and when MF_x,y is greater than the threshold, it is determined that the y^th pixel on the x^th line in the composite video signal is in the motion status, otherwise, the y^th pixel on the x^th line in the composite video signal is in the still status.

6. The method of motion detection for a 3D comb filter video decoder of claim 5, wherein the motion factors MF_x,y are the motion factors of the m^th frame.

7. A method of motion detection for a 3D comb filter video decoder, comprising:

sampling a composite video signal to obtain a sampled data F_m+1P_x,y, wherein F_m+1P_x,y represents a sampled data of a y^th pixel on an x^th line of an (m+1)^th frame in the composite video signal, and m, x, y are positive integers greater than or equal to 0, wherein the composite video signal is a signal for a PAL system, and sampling the composite video signal uses a frequency which is 4 times the subcarrier frequency in the composite video signal to sample; and

obtaining three stored sampled data F_mP_x,y, F<sub>m−

1</sub>P_x,y, F<sub>m−

2</sub>P_x,y, previously sequentially sampled directly from the composite video signal and stored in a storing means, wherein the sampled data F_m+1P_x,y and the three previously sequentially sampled data F_mP_x,y, F<sub>m−

1</sub>P_x,y, F<sub>m−

2</sub>P_x,y are obtained by directly sampling the composite video signal when the subcarrier phase is equal to 0.25π

, 0.75π

, 1.25π

, and 1.75π

, sequentially;

using the sampled data F_m+1P_x,y and the three stored sampled data F_mP_x,y, F<sub>m−

1</sub>P_x,y, F<sub>m−

2</sub>P_x,y to determine a motion/still status of the composite video signal, comprising;

using F_m+1P_x,y, F_mP_x,y, F<sub>m−

1</sub>P_x,y, and F<sub>m−

2</sub>P_x,y to calculate and obtain a plurality of max differences MD_x,y, wherein MD_x,y represents a max difference of the y^th pixel on the x^th line;

averaging 4 max differences of the contiguous pixels selected to obtain a motion factor MF_x,y, wherein MF_x,y represents a motion factor of the y^th pixel on the x^th line; and

detecting MF_x,y to determine the motion/still status of the y^th pixel on the x^th line in the composite video signal.

8. The method of motion detection for a 3D comb filter video decoder of claim 7, wherein the step of calculating and obtaining MD_x,y further comprises:

calculating and obtaining a plurality of luma differences LD_x,y, wherein LD_x,y represents a luma difference of the y^th pixel on the x^th line, and is calculated based on an equation;

LD_x,y=|F_mP_x,y+F<sub>m−

2</sub>P_x,y−

F_m+1P_x,y−

F<sub>m−

1</sub>P_x,y|;

calculating and obtaining a plurality of intermediate differences IMD_x,y, wherein IMD_x,y represents an intermediate difference of the y^th pixel on the x^th line, and is calculated based on an equation;

IMD<sub>i,2j−

1</sub>=Max{|F_m+1P<sub>i,2j−

1</sub>−

F<sub>m−

2</sub>P<sub>i,2j−

1</sub>|, |F_mP<sub>i,2j−

1</sub>−

F<sub>m−

1</sub>P<sub>i,2j−

1</sub>|};

IMD_i,2j=Max{|F_m+1P_i,2j−

F_mP_i,2j|, |F<sub>m−

1</sub>P_i,2j−

F<sub>m−

2</sub>P_i,2j|}; and

calculating and obtaining MD_x,y, which is calculated based on an equation;

MD_x,y=a*IMD_x,y+(1−

a)*LD_x,y;

wherein, a is a real number greater than 0 and less than 1, and i, j are positive integers.

9. The method of motion detection for a 3D comb filter video decoder of claim 7, wherein the step of detecting MF_x,y to determine the motion/still status of the y^th pixel on the x^th line in the composite video signal further comprises:

providing a threshold; and

comparing MF_x,y with the threshold, and when MF_x,y is greater than the threshold, it is determined that the y^th pixel on the x^th line in the composite video signal is in the motion status, otherwise, the y^th pixel on the x^th line in the composite video signal is in the still status.

10. The method of motion detection for a 3D comb filter video decoder of claim 9, wherein the motion factors MF_x,y are the motion factors of the m^th frame.