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題 名 | Progressive Transmission for Moving Images=漸進式視訊影像傳輸 |
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作 者 | 張穎文; | 書刊名 | 中州學報 |
卷 期 | 20 2004.12[民93.12] |
頁 次 | 頁21-33 |
分類號 | 312.1 |
關鍵詞 | 視訊影像; 影像傳輸; Scalable video coding; MPEG4; FGS; |
語 文 | 英文(English) |
中文摘要 | 隨著網際網路技術日漸成熟,透過網際網路傳送即時影音資訊也日益受到重視。由於網際網路上可用頻寬會隨著時間而有不同的變動,在這個需求下能夠適應網路頻寬變動的可調性視訊編碼方式及彈性的串流策略便越顯重要。在本論文中,我們提出一個以小波為基礎的可調性視訊編碼方式。在編碼端,編碼器將餘值係數編碼成數個增強階層的位元串流。位元串流可以視網路頻寬的需求而任意地捨棄某些部分。將餘值影像經小波轉換後,重新排列成小波區塊的形式,這些小波區塊依據其重要性區分成三類並保留不同比例的餘值係數。我們提出依照上述分類時保留係數的特性的編碼方式。解碼端將收到的增強層位元串流與基礎層位元串流一起產生較佳的重建視訊。根據實驗結果,在PSNR方面加入增強層後所產生的重建視訊將比只有基礎層所產生的重建視訊提升至2.5 dB 。另外本文中所提出的方法與 MPEG-4 標準 FGS 相比較,結果顯示 PSNR 提升 0.5 dB 。 |
英文摘要 | In this paper, We propose a scalable video coding based on wavelet scheme. The scalability technology plays an important role in multimedia communications. With respect to encoding, a scalable video encoder encodes predictive residual coefficients into several layers of a bit-stream. According to the bandwidth of the network, the bit-stream of the enhancement layer is truncated at various bit-rates. The residual image is reordered to form wavelet blocks. Wavelet blocks are classified into three types, and the most significant coefficients in each type of block are preserved. After the coefficients are preserved, significant coefficients are encoded using the concept of the significant link. With respect to decoding, the bit-stream of the enhancement layer is combined with the bit-stream of the base layer to reconstruct a better quality video. In a simulation, the PSNR of the reconstructed video with the enhancement layers is enhanced to 2.5 dB over that of the reconstructed video with only the base layer bit-stream. Moreover, the proposed method outperforms MPEG-4 FGS by around 0.5 dB in terms of PSNR. |
本系統中英文摘要資訊取自各篇刊載內容。