Improvement of Transform-Skip Mode in Lossy Intra Coding with 3-Tap Filters

Alvar, Saeed Ranjbar
Kamışlı, Fatih
Using transforms in video coding is an effective method in reducing the spatial redundancy. However, for some cases applying transforms does not reduce the spatial redundancy. For these cases, transforms are skipped and the prediction error is directly quantized and then entropy coded. To further reduce the spatial redundancy in the transform skipped blocks, a pixel-by-pixel lossy intra prediction method based on a two dimensional correlation model is proposed in this paper. In the proposed method, three reconstructed neighboring pixels are used to obtain the prediction. Neighboring pixels and the prediction weights change depending on the selected intra mode. The results of the experiments on different test classes in HEVC version 1 and HEVC Range Extension (RExt) reference softwares show that the proposed method can achieve gains up to approximately 0.5% BD-rate for All-Intra lossy coding compared to HEVC version 1 and the Range Extensions of the HEVC.


Intra-frame Coding with Recursive Intra Prediction and Adapted Block Transforms
Tekeli, Nihat; Kamışlı, Fatih (2014-12-10)
Conventional intra-frame coding is performed in two steps. First, a block of pixels are predicted by copying previously reconstructed neighbor pixels of the block along an angular direction inside the block. Then, the prediction residual block is transform-coded with the well-known 2-D Discrete Cosine Transform (DCT). Recently, it has been shown that transforming the intra prediction residuals with the odd type-3 Discrete Sine Transform (ODST-3) along the prediction direction and the DCT along the perpendic...
Improved prediction methods for scalable predictive animated mesh compression
Bici, M. Oguz; Akar, Gözde (2011-10-01)
Animated meshes represented as sequences of static meshes sharing the same connectivity require efficient compression. Among the compression techniques, layered predictive coding methods efficiently encode the animated meshes in a structured way such that the successive reconstruction with an adaptable quality can be performed. The decoding quality heavily depends on how well the prediction is performed in the encoder. Due to this fact, in this paper, three novel prediction structures are proposed and integ...
Construction of Some Codes Suitable for Both Side Channel and Fault Injection Attacks
Carlet, Claude; GÜNERİ, CEM; Mesnager, Sihem; Özbudak, Ferruh (2018-12-30)
Using algebraic curves over finite fields, we construct some codes suitable for being used in the countermeasure called Direct Sum Masking which allows, when properly implemented, to protect the whole cryptographic block cipher algorithm against side channel attacks and fault injection attacks, simultaneously. These codes address a problem which has its own interest in coding theory.
On lossless intra coding in HEVC with 3-tap filters
Alvar, Saeed Ranjbar; Kamışlı, Fatih (2016-09-01)
This paper presents a pixel-by-pixel spatial prediction method for lossless intra coding within High Efficiency Video Coding (HEVC). Previous pixel-by-pixel spatial prediction methods use only two neighboring pixels for prediction, based on the angular projection idea borrowed from block-based intra prediction in lossy coding, or are based on ad hoc methods applied in some intra modes. This paper explores a pixel-by-pixel prediction method which uses three neighboring pixels for prediction according to a tw...
Kamışlı, Fatih (2012-11-30)
Intra prediction is an important part of intra-frame coding. A number of approaches have been proposed to improve intra prediction including a general linear prediction approach in which a weighted sum of all available neighbor pixels is used to predict each block pixel. An important part of this approach is the determination of the used weights. One method to determine the weights is to use the least-squares solution of an overdetermined linear system of weights. In this paper, we present an alternative ap...
Citation Formats
S. R. Alvar and F. Kamışlı, “Improvement of Transform-Skip Mode in Lossy Intra Coding with 3-Tap Filters,” 2016, Accessed: 00, 2020. [Online]. Available: