This study proposes a fast mode decision algorithm combined with image texture direction and spatial correlation in high-efficiency video coding (HEVC) to reduce the number of candidate patterns in the rough mode decision(RMD) and to speed up the frame of mode selection. In the HEVC algorithm

the Sobel operator is used to obtain the texture direction of the current block Prediction Union (PU)

in order to select the corresponding angle prediction model to comprise the RMD candidate list

and the spatial correlation of images is adopted to add the optimal mode of the neighboring PU to the candidate list. The proposed algorithm will reduce the number of candidate patterns from 35 to less than 10 in the RMD. Thus

this method significantly shortens the encoding time by 34.9%

with the bit-rate increasing to 0.41% and the PSNR decreasing to 0.0314 dB. Resultsshow that this method significantly reduces the complexity of RMD algorithm and improves the efficiency of HEVC coding when the encoding quality is invariant.