Encoding method, decoding method, encoding device and decoding device

Abstract

Disclosed is an encoding method including a transform step (S110) for generating a transform output signal by way of transforming an input signal; a quantization step (S120) for generating quantization coefficients by way of quantizing the transform output signal; and an entropy encoding step (S130) for generating an encoded signal by way of entropy encoding the quantized coefficients. The transform step (S110) includes a first transform step (S112) for generating a first transform output signal by way of performing a first transform on the input signal using a first transform coefficient; and a second transform step (S116) for generating a second transform output signal by way of performing a second transform using a second transform coefficient on a first partial signal which is a portion of the first transform output signal. In the entropy encoding step (S130), a difference between a predetermined value, and an element included in the second transform coefficient or a second inverse transform coefficient, is calculated, and by way of compression coding the calculated difference, the second transform coefficient or the second inverse transform coefficient is compression coded.

Description

Technical field [0001] The present invention relates to an encoding method for encoding audio, still images, and moving images, and more particularly to an encoding method including a transformation process of transforming an input signal from a time-space domain to a frequency domain. Background technique [0002] In order to compress audio data and moving image data, a number of audio coding standards and moving image coding standards have been developed. As examples of video coding standards, ITU-T standards called H.26x and ISO / IEC standards called MPEG-x can be cited. The latest video coding standard is called H.264 / MPEG-4AVC. [0003] figure 1 It is a block diagram showing the structure of a conventional encoding device 900. Such as figure 1 As shown, the encoding device 900 includes a transform unit 910, a quantization unit 120, and an entropy encoding unit 930, and encodes audio data and moving image data at a low bit rate. [0004] The transform unit 910 transforms an inp...

AI Technical Summary

Problems solved by technology

[0024] As mentioned above, in KLT, there is a problem that the amount of calculation is large and the data volume of transform coefficients is large, so it is difficult to use KLT in conventional encoding.

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