Discrete cosine inverse transformation method and its device

Abstract

This invention discloses a scattered cosine inverse transformation method including: carrying out amplifying, correcting and rounding process to the transformed coefficients input initially in the process of scattered cosine inverse transformation to digital signals based on AAN algorithm to substitute corresponded floating-point multiplication operation appearing in the transforming process based on a fixed-point shift accumulation operation and carrying out corresponding reduction process to the final inverse transformation results. This invention also discloses a device.

Description

technical field [0001] The present invention relates to discrete cosine transform (DCT, Discrete Cosine Transform) technology and discrete cosine transform (IDCT, Inverse Discrete Cosine Transform) technology in the field of communication technology, in particular to an inverse discrete cosine transform method and device thereof. Background technique [0002] Since Ahmed and Rao proposed the definition of discrete cosine transform (DCT, Discrete CosineTransform) in 1974, discrete cosine transform and inverse discrete cosine transform (IDCT, Inverse DiscreteCosine Transform) have become widely used in signal processing and image processing in the field of communication. , especially for voice compression and image compression codec processing, so DCT technology and IDCT technology has always been a research hotspot in the international academic circles and high-tech industries. [0003] Due to the requirement of real-time communication characteristics, in the Still Picture Ex...

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Problems solved by technology

[0008] To sum up, although the AAN algorithm belongs to the IDCT fast algorithm technology, when performing IDCT transformation processing on a one-dimensional 8-point image signal based on the AAN algorithm, it still needs to perform 5 cosine function value floating-point multiplication operations, because the two-dimensional 8×8 When performing DCT and IDCT transform codec processing on image signals of points, the two-dimensional image signals are usually decomposed into row-one-dimensional and column-one-dimensional situations to be processed separately. In this way, an 8×8-point two-dimensional image is 80 floating-point multiplication operations are required when the signal is processed by DCT and IDCT. Because the floating-point multiplication operation process consumes a lot of system processing resources, the resources consumed include the consumption of computing time and the consumption of system software and hardware resources. etc. Therefore, it is necessary to further optimize the IDCT transformation processing process based on the AAN algorithm to speed up the transformation processing speed of IDCT and better meet the needs of modern real-time communication services.

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