Embedded foveation image coding
Embedded foveation image coding
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DOI：
10.1109/83.951527
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发表时间：
2001-10-01
影响因子：
10.6
通讯作者：
Bovik, AC
中科院分区：
文献类型：
--
作者：
Wang, Z;Bovik, AC
人类视觉系统（HVS）在采样、编码、处理和理解方面具有高度的空间可变性。HVS的空间分辨率在注视点（视觉中心凹点）附近最高，并随着偏心率的增加而迅速降低。通过利用这一事实，可以从外围区域去除相当多的高频信息冗余，并且仍然重建感知上质量良好的图像。近年来，嵌入式小波图像编码算法取得了巨大的成功，如嵌入式零树小波（EZW）和层次树集合分割（SPIHT）算法。嵌入式小波编码不仅提供了非常好的压缩性能，而且还具有这样的特性，即比特流可以在任何点处被截断，并且仍然可以被解码以重建相当好的质量图像。在本文中，我们提出了一个嵌入式的视觉中心凹图像编码（EFIC）算法，它命令编码的比特流，以优化视觉中心凹质量在任意的比特率。一种基于视觉聚焦的图像质量度量，即视觉聚焦小波图像质量指数（FWQI），在EFIC系统中起着重要的作用。为了提高编码效率，我们还提出了一种改进的SPIHT算法。实验表明，EFIC集成了视觉中心滤波和视觉中心图像编码，并在视觉中心图像质量测量方面表现出非常好的编码性能和可扩展性。
The human visual system (HVS) is highly space-variant in sampling, coding, processing, and understanding. The spatial resolution of the HVS is highest around the point of fixation (foveation point) and decreases rapidly with increasing eccentricity. By taking advantage of this fact, it is possible to remove considerable high-frequency information redundancy from the peripheral regions and still reconstruct a perceptually good quality image. Great success has been obtained recently by a class of embedded wavelet image coding algorithms, such as the embedded zerotree wavelet (EZW) and the set partitioning in hierarchical trees (SPIHT) algorithms. Embedded wavelet coding not only provides very good compression performance, but also has the property that the bitstream can be truncated at any point and still be decoded to recreate a reasonably good quality image. In this paper, we propose an embedded foveation image coding (EFIC) algorithm, which orders the encoded bitstream to optimize foveated visual quality at arbitrary bit-rates. A foveation-based image quality metric, namely, foveated wavelet image quality index (FWQI), plays an important role in the EFIC system. We also developed a modified SPIHT algorithm to improve the coding efficiency. Experiments show that EFIC integrates foveation filtering with foveated image coding and demonstrates very good coding performance and scalability in terms of foveated image quality measurement.