Patent ID: 8406286
Filing Date: 2013-03-26
Classification: H04N

Abstract:
1. A method for selecting the best mode of intra prediction coding for video coding, comprising the steps of: obtaining an estimated residual error corresponding to a block to be coded by subtracting each pixel value in a predictive block from an original pixel value on a corresponding position in the block to be coded; obtaining DCT coefficients corresponding to each pixel in the block to be coded by performing DCT to the estimated residual error; comparing the obtained DCT coefficient corresponding to each of the pixels in the block to be coded with a value on a corresponding position in a Quantization Coefficient Classification Table, determining that the DCT coefficient after quantization is zero coefficient when an absolute value of the DCT coefficient is smaller than the value on the corresponding position in the Quantization Coefficient Classification Table, and determining that the DCT coefficient after quantization is ±1 coefficient when the absolute value of the DCT coefficient is bigger than or equal to the value on the corresponding position in the Quantization Coefficient Classification Table and smaller than double of the value on the corresponding position in the Quantization Coefficient Classification Table; determining an estimated rate of the block to be coded by linearity fitting according to a characteristic of a Context-based Adaptive Variable Length Coding method and the determined number of pixels of which the DCT coefficient after quantization is zero coefficient and the determined number of pixels of which the DCT coefficient after quantization is ±1 coefficient in the block to be coded; constructing a rate distortion cost function based on the estimated rate of the block to be encoded by using the estimated residual error corresponding to the block to be coded as distortion measurement; computing rate distortion costs for all predictive modes by using the constructed function; and selecting a predictive mode with the minimum rate distortion cost as the best mode of intra prediction coding according to computing results.