Integer wavelet transform for embedded lossy to lossless image compression
Integer wavelet transform for embedded lossy to lossless image compression
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DOI：
10.1109/83.908504
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发表时间：
2001-03-01
影响因子：
10.6
通讯作者：
Kunt, M
中科院分区：
文献类型：
--
作者：
Reichel, J;Menegaz, G;Kunt, M
使用离散小波变换 (DWT) 进行嵌入式有损图像压缩现已得到广泛应用。 DWT 的可能实现之一是提升方案 (LS)。由于 LS 的结构保证了完美的重建，因此可以使用非线性变换，从而实现高效的无损压缩。整数小波变换（IWT）就是其中之一。这是 DWT 的一个有趣的替代方案，因为它的率失真性能相似并且可以预测差异。本主题在理论框架中进行研究。提出了由于使用 IWT 而不是 DWT 进行有损压缩而导致的性能下降的模型。舍入操作被建模为加性噪声。然后噪声通过 LS 结构传播，以测量它们对重建像素的影响。使用以随机噪声作为输入的模拟来验证该方法。它使用著名的 EZW [1] 算法压缩的图像准确预测所获得的结果。还进行了实验来测量比特率和视觉质量方面的差异。这样可以更好地了解 IWT 在应用于有损图像压缩时的影响。
The use of the discrete wavelet transform (DWT) for embedded lossy image compression is now well established. One of the possible implementations of the DWT is the lifting scheme (LS). Because perfect reconstruction is granted by the structure of the LS, nonlinear transforms can be used, allowing efficient lossless compression as well. The integer wavelet transform (IWT) is one of them. This is an interesting alternative to the DWT because its rate-distortion performances is similar and the differences can be predicted.This topic is investigated in a theoretical framework. A model of the degradations caused by the use of the IWT instead of the DWT for lossy compression is presented. The rounding operations are modeled as additive noises. The noises are then propagated through the LS structure to measure their impact on the reconstructed pixels. This methodology is verified using simulations with random noise as input. It predicts accurately the results obtained using images compressed by the well-known EZW [1] algorithm. Experiments are also performed to measure the difference in terms of bitrate and visual quality. This allows to a better understanding of the impact of the IWT when applied to lossy image compression.