Perceptual attributes of image quality in JPEG-coded images

The perceived overall image quality of sequential baseline-coded JPEG images depends on the achieved compression ratio, which is controlled by the 'quality parameter' of the coding algorithm. This 'quality parameter' can vary between 0 and 100, ranging from poor image quality with large visible distortions to high-quality images that cannot be distinguished from the original. In two experiments, dissimilarity data and categorical-numerical scaling data were gathered to determine the underlying attributes of image quality and their perceived strength. Although several distortions are perceived in IPEG images, blockiness, ringing and blur, the best fit of the dissimilarity data is a one-dimensional stimulus configuration. This is probably due to the fact that the distortions are highly correlated in sequential baseline-coded JPEG images.