Apparatus and Method For Encoding and Decoding Moving Picture Using Adaptive Scanning

• US 20080285644A1
• Filed: 10/19/2006
• Published: 11/20/2008
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute, kwangwoon university research institute for industry cooperation
• Inventors: Kim, Kyu-Heon, Kang, Kyeong-Ok, Hong, Jin-Woo, Seo, Jeong-Il, Lee, Yung-Lyul, Oh, Seoung-Jun, Sim, Dong-Gyu, Hur, Jae-Ho, Kim, Wook-Joong, Han, Ki-Hun
• Granted Patent: US 8,199,819 B2
• Time in Patent Office: Days
• US Class Current: 375/240.2
• CPC Class Codes: H04N 19/129 Scanning of coding units, e.g. zig-zag scan of transform coefficients or flexible macroblock ordering [FMO]
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

Provided is an apparatus and method for encoding/decoding moving pictures based on adaptive scanning. The moving picture apparatus and method can increase a compression rate based on adaptive scanning by performing intra prediction onto blocks of a predetermined size, and scanning coefficients acquired from Discrete Cosine Transform (DCT) of a residue signal and quantization differently according to the intra prediction mode. The moving picture encoding apparatus includes: a mode selector for selecting and outputting a prediction mode; a predictor for predicting pixel values of pixels to be encoded of an input video based on the prediction mode to thereby output a residue signal block; a transform/quantization unit for performing DCT onto the residue signal block and quantizing the transformed residue signal block; and an encoder for adaptively scanning and encoding the quantized residue signal block based on the prediction mode.

Claims

1. An apparatus for encoding moving picture based on adaptive scanning, comprising:

a mode selecting means for selecting and outputting a prediction mode;

a predicting means for predicting pixel values of pixels to be encoded of an input video based on the prediction mode to thereby output a residue signal block;

a transform/quantization means fox performing Discrete Cosine Transform (DCT) onto the residue signal block and quantizing the transformed residue signal block; and

an encoding means for adaptively scanning and encoding the quantized residue signal block based on the prediction mode.

2. The encoding apparatus as recited in claim 1, wherein when the prediction mode is a vertical mode, the encoding means executes a horizontal preference scanning method where the blocks of a first row are scanned with priority.

3. The encoding apparatus as recited in claim 1, wherein when the prediction mode is a horizontal mode, the encoding means executes a vertical preference scanning method where the blocks of a first column are scanned with priority.

4. The encoding apparatus as recited in claim 1, wherein when the prediction mode is neither the vertical mode nor the horizontal mode, the encoding means executes a zigzag scanning.

5. The encoding apparatus as recited in claim 1, wherein the encoding means performs entropy encoding onto coefficients acquired and arrayed by performing adaptive scanning based on the prediction mode.

6. An apparatus for decoding moving picture based on adaptive scanning, comprising:

an entropy decoder for receiving encoded bitstream, decoding the encoded bitstream based on an entropy decoding method, and outputting decoded signals;

a scanning method detector for receiving the decoded signals from the entropy decoder, acquiring information on a scanning method used in the encoding of the decoded signals, and outputting the scanning method information along with the decoded signals; and

a video recovering unit for recovering the decoded signals based on the scanning method and outputting a recovered video,

wherein the scanning method is an adaptive scanning where different scanning methods are applied based on an intra prediction mode.

7. The decoding apparatus as recited in claim 6, wherein when the prediction mode is a vertical mode, the adaptive scanning is a horizontal preference scanning where the blocks of a first row are scanned with priority.

8. The decoding apparatus as recited in claim 6, wherein when the prediction mode is a horizontal mode, the adaptive scanning is a vertical preference scanning where the blocks of a first column are scanned with priority.

9. The decoding apparatus as recited in claim 6, wherein when the prediction mode is neither the vertical mode nor the horizontal mode, the adaptive scanning is a zigzag scanning.

10. A method for encoding moving pictures based on adaptive scanning, comprising the steps of:

a) selecting a prediction mode;

b) predicting pixel values of pixels to be encoded of an input video based on the selected prediction mode and outputting a residue signal block;

c) performing Discrete Cosine Transform (DCT) onto the residue signal block and quantizing the transformed residue signal block;

d) adaptively scanning the quantized residue signal block based on the prediction mode and outputting scanned coefficients; and

e) encoding the scanned coefficients.

11. The encoding method as recited in claim 10, wherein the adaptively scanning step d) includes the steps of:

d1) determining whether the prediction mode is a vertical mode; and

d2) horizontally scanning the blocks of a first row with priority, when the prediction mode is the vertical mode.

12. The encoding method as recited in claim 11, wherein the adaptively scanning step d) further includes the steps of:

d3) determining whether the prediction mode is a horizontal mode, when the prediction mode is the vertical mode; and

d4) vertically scanning the blocks of a first column with priority, when the prediction mode is the horizontal mode.

13. The encoding method as recited in claim 12, wherein the adaptively scanning step d) further includes the step of:

d5) performing zigzag scanning when the prediction mode is neither the vertical mode nor the horizontal mode.

14. A method for decoding moving pictures based on adaptive scanning, comprising the steps of:

a) performing entropy decoding onto encoded bit stream to thereby produce entropy-decoded signal;

b) determining a scanning method of the encoded bit stream which is entropy-decoded in the step a); and

c) recovering the entropy-decoded signal according to the scanning method and outputting recovered picture,

wherein the scanning method is adaptively used according to an intra prediction mode used when the encoded bit stream is encoded.

15. The method as recited in claim 14, wherein the scanning method determined in the step b) is one among a vertical mode, a horizontal mode, and a zigzag mode.

16. The method as recited in claim 15, wherein, according to the scanning method determined in the step b), blocks of a first row are scanned with priority, when the scanning method is the vertical mode;

blocks of a first column are scanned with priority, when the scanning method is the horizontal mode;

or blocks are scanned in zigzag, when the scanning method is zigzag mode.