288 pp. per issue
6 x 9, illustrated
2014 Impact factor:

Neural Computation

January 1, 1999, Vol. 11, No. 1, Pages 267-296
(doi: 10.1162/089976699300016917)
© 1999 Massachusetts Institute of Technology
JPEG Quality Transcoding Using Neural Networks Trained with a Perceptual Error Measure
Article PDF (729.27 KB)

A JPEG Quality Transcoder (JQT) converts a JPEG image file that was encoded with low image quality to a larger JPEG image file with reduced visual artifacts, without access to the original uncompressed image. In this article, we describe technology for JQT design that takes a pattern recognition approach to the problem, using a database of images to train statistical models of the artifacts introduced through JPEG compression. In the training procedure for these models, we use a model of human visual perception as an error measure. Our current prototype system removes 32.2% of the artifacts introduced by moderate compression, as measured on an independent test database of linearly coded images using a perceptual error metric. This improvement results in an average PSNR reduction of 0.634 dB.