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題 名 | Bit Rate Reduction Techniques for Absolute Moment Block Truncation Coding=降低動量絕對值方塊截短編碼位元率技巧之研究 |
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作 者 | 陳文儉; 戴顯權; | 書刊名 | 中國工程學刊 |
卷 期 | 22:5 1999.09[民88.09] |
頁 次 | 頁661-667 |
分類號 | 312.1 |
關鍵詞 | 方塊截短編碼動量; 絕對值方塊截短編碼; 位元組導向; 畢諾掃瞄; Block truncation coding; AMBTC; Byte-oriented; Peano scan; |
語 文 | 英文(English) |
中文摘要 | 方塊截短編碼是利用影像局部性來保留動量之量化器,其有低計算量及少記憶體 需求的優點,但是其位元率只有 2bpp。 一個更有效率且被廣泛使用的動量絕對值方塊截短 編碼演算法可以有更低的計算量及較佳重建結果。本文提出針對動量絕對值方塊截短編碼二 個輸出值做進一步壓縮, 經過此後處理後, 在重建品質不變下,位元率可從 2bpp 降低到 1.6 ∼ 1.7bpp。 |
英文摘要 | Block Truncation Coding uses a two-level moment preserving quantizer that adapts to local properties of the images. It has the features of low computation load and low memory requirement while its bit rate is only 2.0 bits per pixel. A more efficient algorithm, the absolute moment ETC (AMBTC) has been extensively used in the field of signal compression because of its simple computation and better MSE performance. We propose postprocessing methods to further reduce the entropy of two output data of AMBTC, including the bit map and two quantization data (a, b). A block of a 2x4 bit map is packaged into a byte-oriented symbol. The entropy can be reduced from 0.965 bpp to 0.917 bpp on average for our test images. The two subimages of quantization data (a, b) are postprocessed by the Peano Scan. This postprocess can further reduce differential entropy about 0.4 bit for a 4x4 block. By applying arithmetic coding, the total bit reduction is about 0.3-0.4 bpp. The bit rate can reach 1.6-1.7 bpp with the same quality as traditional AMBTC. |
本系統中英文摘要資訊取自各篇刊載內容。