Study on Reduction of Image Quality Degradation on JPEG Image and Restoration of Out-of-Focus JPEG Image

[2003]JPEG图像会受到块DCT域上量化产生的块伪影和蚊子噪声的影响。本研究的目的是在简单的解码后，用图像恢复方法代替平滑方法来减少图像质量的退化。该方法基于边缘自适应恢复方法；正则化算子取决于边缘方向，正则化参数取决于局部活动。考虑了分块DCT域上量化的方差。[2004]JPEG图像会因块DCT域上量化产生的块伪影和蚊子噪声而退化，也可能因失焦而退化。本研究的目的是在不增强遮挡伪影和蚊子噪声的情况下，使失焦JPEG图像清晰。该方法基于边缘自适应恢复方法；正则化算子取决于边缘方向，正则化参数取决于局部活动。考虑了分块DCT域上量化的方差。

[2003]JPEG images are degraded by blocking artifacts and mosquito noise caused by quantization on the block DCT domain. The purpose of this study is reduction of image quality degradation by means of the image restoration method instead of the smoothing method after the simple decoding. This proposed method is based on the edge-adaptive restoration method ; the regularizing operator depends on the edge orientation, and the regularizing parameter depends on the local activity. The variance of the quantization on the block DCT domain is taken into consideration.[2004]JPEG images are degraded by blocking artifacts and mosquito noise caused by quantization on the block DCT domain, and also may be degraded by out-of-focus. The purpose of this study is to make out-of-focus JPEG images sharp without enhancing the blocking artifacts and the mosquito noise. This proposed method is based on the edge-adaptive restoration method ; the regularizing operator depends on the edge orientation, and the regularizing parameter depends on the local activity. The variance of the quantization on the block DCT domain is taken into consideration.