Efficient Algorithm for Removing Blocking Artifacts in JPEG Compressed Images

Despite their widespread popularity, the Joint Photographers Expert Group (JPEG) compression standard can lead to noticeable ´blocking artifacts´. High frequency details of the coded images are mainly contaminated by quantization noise. The deblocking approach of JPEG compressed images using overcomplete wavelet representation can be improved by preserving the image details and reducing the effect of quantization noise as much as possible. An estimation of the actual pixel is obtained from the decoded image. The edge information is extracted from this estimated image by exploiting the cross-scale correlations among the wavelet coefficients and is protected, while the blocking effects in the smooth background regions are smoothed out in the wavelet domain without much blurring. A better improvement in visual quality is achieved if Dual Tree Complex Wavelet filters are used instead of the Dyadic Discrete Wavelet Transform.