Enhanced Intra Mode Bit Skip Algorithm for H.264/AVC
| Autor: | Ming-yi Liu, 劉明宜 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 One of the main contributions of H.264 is the intra prediction in spatial domain, which increases the coding performance of I-frame significantly. Intra4×4 mode provides nine directional prediction modes for every 4×4 block. However, for each 4×4 block, 1 or 4 bits are required for indicating intra mode in the encoded bit stream for successfully decoding. Therefore, 16 ~ 64 bits are required to represent intra mode bits for each intra4×4 macroblock. To reduce this burden, Dae-Yeon Kim proposed an algorithm called: “adaptive intra mode bit skip (AIMBS)” in 2008. If all reference pixels of current block are quite similar, the DC mode can be selected as the prediction mode without significant distortion so that the prediction mode bit can be skipped in the proposed method. But this method can be improved by considering the bit skip for more modes. The reference pixels usually exist the same direction with current block. In this work, the correlation between vertical and horizontal differences of reference pixels and encoded modes are investigated. The mode skip of vertical and horizontal prediction modes is integrated with AIMBS to achieve better coding efficiency. The simulation results show that the proposed mechanism can improve 0.027dB BD-PSNR and reduce BD-Rate by 0.66% at 1080P compared with AIMBS on average. We observe that this method can be further improved by including more modes for bit skipping. In this work, the correlation between vertical and horizontal differences of reference pixels and encoded modes are investigated. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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