Sunday, March 20th, 2005
What makes an image look good?
I gave a presentation on image quality and some related topics (global and local image phase, steerable pyramid wavelet transforms, statistical modeling of natural images, and structural image quality).
Some of the most interesting questions resulting from the talk were:
How should one interpret the diagram from the Phase & Perception of Blur paper — specifically, what do the converging lines represent? My current interpretation is that they are equal-phase contours corresponding to a well-localized feature point at any scale.
What is the gaussian scale mixture (GSM) model? I hope to better explain and interpret this in an upcoming blog entry.
How do SSIM and CWSSIM compare to the latest perceptual error-based models of image quality (such as ones derived from the Watson paper)? A specific test could evaluate structural methods with images that are only degraded with a just-noticable difference (JND). In other words, look at errors that are just visible at the threshold of human perception instead of the gross “suprathreshold” errors that we looked at before.
