A triage metric is proposed to determine the extent of blocking and contouring artifacts in an image due to JPEG compression. It is found that this metric has a linear correlation with subjective judgements of print quality. This triage metric can be used to determine the amount of needed image enhancement or achieve a good trade-off between image quality and system throughput.
Qing Yu, Jiebo Luo, Michael E. Miller, "A Triage Metric for Determining the Extent of DCT-Based Compression Artifacts in a Digital Image" in Journal of Imaging Science and Technology, 2002, pp 443 - 452, https://doi.org/10.2352/J.ImagingSci.Technol.2002.46.5.art00007