Abstract:There are structural textures in the intra and inter residual blocks in video coding. There is also such a causal relationship between the texture characteristic and orthogonal transforms: the energy concentration effect is poor when the textures are strong

and conversely the opposite. Therefore

an adaptive transform skip mode is proposed based on the horizontal and vertical texture characteristic of the residual blocks in this paper. Firstly

the sum of the absolutes values of horizontal and vertical gradients are counted by computing the horizontal and vertical gradients of the prediction residual blocks based on the texture characteristic of the prediction residual blocks. The experimental horizontal and vertical gradient thresholds

which decide whether horizontal or vertical transform should be skipped to achieve better coding gains

are designed based on lots of experiments. Then

an adaptive scan mode is presented based on the transform skip mode. The final simulation results show that

compared with the recent HEVC conference software HM4.0

our proposed algorithm achieves 0.82%-8.92% more Bitrates saving and a little PSNR enhancement with some running time increment.