Video encoding method and device and decoding method and device

• US 9,788,013 B2
• Filed: 05/09/2016
• Issued: 10/10/2017
• Est. Priority Date: 09/28/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hong, Yoon-Mi, Han, Woo-Jin, Cheon, Min-Su, Chen, Jianle
• Primary Examiner(s): KALAPODAS, DRAMOS
• Application Number:
  US15/149,931
• Publication Number:
  US 20160255372A1
• Time in Patent Office: 519 Days
• CPC Class Codes: G06F 17/147 Discrete orthonormal transforms, e.g. discrete cosine transform, discrete sine transform, and variations therefrom, e.g. modified discrete cosine transform, integer transforms approximating the discrete cosine transform G06F17/145 takes precedence
• CPC Class Codes: H04N 19/126 Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/625 using discrete cosine transform [DCT]

Abstract

A video encoding method, a video encoding apparatus, a video decoding method, and a video decoding apparatus are provided. The video encoding method includes producing a fast transform matrix based on a transform matrix which is used for frequency transformation on a block which has a predetermined size; producing a transformed block by transforming the block having the predetermined size by using the fast transform matrix; and performing scaling with respect to the transformed block in order to correct a difference between the transform matrix used for the frequency transformation and the fast transform matrix.

Claims

1. A video decoding apparatus comprising a processor configured to:

receive a quantized transform block which has a predetermined size,

determine a scaling constant for scaling of transform coefficients included in the quantized transform block based on a quantization parameter,

scale the transform coefficients by using the scaling constant, and

inverse-transform the transform block that includes the scaled transform coefficients,

wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72.