Video encoding device and video decoding device

• US 10,432,934 B2
• Filed: 06/08/2012
• Issued: 10/01/2019
• Est. Priority Date: 06/28/2011
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Aoki, Hirofumi, Chono, Keiichi, Senda, Yuzo
• Primary Examiner(s): Hansell, Jr., Richard A
• Application Number:
  US14/009,659
• Publication Number:
  US 20140056349A1
• Time in Patent Office: 2,671 Days
• Field of Search: 37524012
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/50 using predictive coding H04N19/61 takes precedence
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution

Abstract

A video encoding device includes: a quantization step size encoding unit 11 for encoding a quantization step size for controlling quantization granularity; and a quantization step size downsampling unit 12 for downsampling one or more encoded quantization step sizes to generate a quantization step size representative value. The quantization step size encoding unit 11 predicts the quantization step size using the quantization step size representative value.

Claims

1. A video encoding device for dividing input video data into blocks of a predetermined size and applying quantization to each image block obtained by division, to perform a compression-encoding process, comprising:

at least one processor configured to execute machine-readable instructions to implement;

a quantization step size encoding unit configured to encode a quantization step size for controlling granularity of the quantization;

a quantization step size downsampling unit configured to downsample one or more encoded quantization step sizes to generate a quantization step size representative value;

a quantization step size representative value storing unit configured to store the quantization step size representative values generated by the quantization step size downsampling unit;

a quantization step size downsampling control unit configured to control an operation of the quantization step size downsampling unit based on a predetermined operation parameter including at least one of a downsampling scale factor or information indicating a type of computation when generating the quantization step size representative value; and

a multiplexer configured to multiplex at least the operation parameter of the quantization step size downsampling unit, in a compression-encoded video bitstream,

wherein the quantization step size encoding unit is configured to predict the quantization step size using the quantization step size representative value.

2. The video encoding device according to claim 1, wherein the quantization step size encoding unit is configured to use, as the quantization step size representative value, a quantization step size representative value generated using at least an encoded quantization step size in the current frame.

3. The video encoding device according to claim 1, wherein the quantization step size encoding unit is configured to use, as the quantization step size representative value, a quantization step size representative value generated using at least an encoded quantization step size in a different frame.

10. The video encoding device according to claim 1, wherein the processor is further configured to execute machine-readable instructions to implement:

a quantization step size upsampling unit configured to retrieve the quantization step size representative value from the quantization step size representative value storing unit, and upsample the quantization step size representative value.

11. The video encoding device according to claim 3, wherein the processor is further configured to execute machine-readable instructions to implement:

a quantization step size upsampling unit configured to retrieve the quantization step size representative value from the quantization step size representative value storing unit, and upsample the quantization step size representative value.

13. The video encoding device according to claim 1, wherein the quantization step size downsampling control unit configured to control the operation of the quantization step size downsampling unit based on the information indicating a type of computation when generating the quantization step size representative value.

4. A video decoding device for decoding image blocks by applying inverse quantization to input compressed video data, to perform a generation process of video data as a set of the image blocks, comprising:

a quantization step size decoding unit comprising a processor configured to decode quantization step size for controlling granularity of the inverse quantization;

a quantization step size downsampling unit comprising a second processor configured to downsample one or more decoded quantization step sizes to generate a quantization step size representative value;

a quantization step size representative value storing unit configured to store the quantization step size representative values generated by the quantization step size downsampling unit;

a quantization step size downsampling control unit configured to control an operation of the quantization step size downsampling unit based on a predetermined operation parameter including at least one of a downsampling scale factor or information indicating a type of computation when generating the quantization step size representative value; and

a de-multiplexer configured to de-multiplex a bitstream including at least the operation parameter of the quantization step size downsampling unit,

wherein the quantization step size decoding unit is configured to predict the quantization step size using the quantization step size representative value.

5. The video decoding device according to claim 4, wherein the quantization step size decoding unit is configured to use, as the quantization step size representative value, a quantization step size representative value generated using at least a decoded quantization step size in the current frame.

6. The video decoding device according to claim 4, wherein the quantization step size decoding unit is configured to use, as the quantization step size representative value, a quantization step size representative value generated using at least a decoded quantization step size in a different frame.

12. The video decoding device according to claim 4, comprising:

a quantization step size upsampling unit configured to retrieve the quantization step size representative value from the quantization step size representative value storing unit, and upsample the quantization step size representative value.

14. The video decoding device according to claim 4, wherein the quantization step size downsampling control unit configured to control the operation of the quantization step size downsampling unit based on the information indicating a type of computation when generating the quantization step size representative value.

7. A method, implemented by a processor, for dividing input video data into blocks of a predetermined size and applying quantization to each image block obtained by division, to perform a compression-encoding process, comprising:

encoding, with the processor, a quantization step size for controlling granularity of the quantization;

downsampling, with the processor, one or more encoded quantization step sizes to generate a quantization step size representative value;

storing, with the processor, the quantization step size representative values generated by the downsampling;

controlling, with the processor, the downsampling based on a predetermined operation parameter including at least one of a downsampling scale factor or information indicating a type of computation when generating the quantization step size representative value;

predicting, with the processor, the quantization step size using the quantization step size representative value; and

multiplexing, with the processor, at least the operation parameter in a compression-encoded video bitstream.

8. The method of claim 7, comprising using, as the quantization step size representative value, a quantization step size representative value generated using at least an encoded quantization step size in a current frame.

9. The method of claim 7, comprising using, as the quantization step size representative value, a quantization step size representative value generated using at least an encoded quantization step size in a different frame.

15. The method of claim 7, wherein the downsampling is controlled based on the information indicating a type of computation when generating the quantization step size representative value.