BLIND PERCEPTUAL QUALITY ASSESSMENT METHODFOR DCT-BASED ENCODED IMAGES

摘要

This paper describes a technique whose purpose is to estimatethe perceptual quality of DCT-based encoded images,without requiring the original data. To achieve this objective,a watermark is embedded in the DCT domain using anon-uniform quantization scheme. At the receiver side, theoriginal DCT coefficients data distribution is estimated usinga maximum likelihood approach. These distributions andthe extracted watermark are then combined to estimate theerror between reference and distorted DCT coefficients. Thiserror is perceptually weighted, using a DCT domain perceptualmodel, allowing to blindly score the quality of the receivedmedia. Results have shown the effectiveness of theproposed algorithm when scoring the quality of images subjectto lossy compression.