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

[2003]由于块DCT域上的量化引起的块伪影和蚊子噪声，JPEG图像被降级。本研究的目的是通过简单解码后的图像恢复方法来代替平滑方法来减少图像质量的下降。该方法基于边缘自适应恢复方法，正则化算子依赖于边缘方向，正则化参数依赖于局部活跃度。考虑了块DCT域上的量化的方差。[2004]由于块DCT域上的量化引起的块伪影和蚊子噪声，JPEG图像会被降级，也可能由于失焦而降级。这项研究的目的是在不增强块效应和蚊子噪声的情况下，使散焦的JPEG图像清晰。该方法基于边缘自适应恢复方法，正则化算子依赖于边缘方向，正则化参数依赖于局部活跃度。考虑了块DCT域上的量化的方差。

[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.