pun@cui.unige.ch (PUN Thierry) (02/21/91)
Hello All this discussion about Turing test photo, psychographics or subjective graphics, etc. basically relates to "psychological" perception. There is great interest in the computer vision community for perceptual studies. While ten years ago the emphasis was on neurophysiology, that is the physiological support of human vision (Marr, computational theory of vision), the interest towards psychological studies is ever increasing. This is not surprising considering the progress made in all image sciences. At the beginning, algorithms were simple (eg. contours extraction in the case of computer vision), and a physiological equivalent was known to exist (Huebel and Wiesel). The fact that the problem was really tough started to be acknowledged later, when the lack of success of computer vision systems became clear. Psychologists working on perception were facing similar difficulties: what are the various functiunalities in the visual system, how do they interact? Research groups working in computer vision more and more collaborate with researchers working in "psychological" perception. Why discussing computer vision in this news group? Because it looks that various imaging branches are converging: people in image synthesis are using theories from image analysis, and conversely. There is an increasing commonality of interest between computer graphics and computer vision. A subject which seems of particular (and fundamental) importance is certainly perception. As a particular exemple, one of the problem we are working on is how a focus of attention is selected, ie. why and how one looks first at some particular points in a scene. Clearly, such a topic is interesting for a computer vision system. Our feeling is that it is also of interest for image synthesis: which will be the part in a synthetized picture that will be scrutinized first? More generally, it would be very interesting to start a discussion on how perceptual studies can be relevant to imaging sciences. This concerns computer graphics as well as computer vision. The Eurographics Working Group on the Relations between image analysis and image synthesis intends focusing on issues of perception and it is open to interested researchers. If there is enough interest, a mailing list could be started for exchanging information. Interested people should contact one of the two persons mentionned below. Thierry Pun, Computer Vision Group Edwin Blake, Dpt. of Interactive Computing Science Center, U-Geneva Systems, 12, rue du Lac, CH-1207 Geneva CWI - Centre for Math. and C.Sc. SWITZERLAND Kruislaan 413, 1098 SJ Amsterdam Phone : +41(22) 787 65 82; fax: 735 39 05 THE NETHERLANDS E-mail: pun@cui.unige.ch Phone: +31 (20) 592 4009 E-mail: edwin@cwi.nl
honig@ics.uci.edu (David Honig) (03/07/91)
In article <4996@cui.unige.ch> pun@cui.unige.ch (PUN Thierry) writes: >As a particular exemple, one of the problem we are working on is how a >focus of attention is selected, ie. why and how one looks first at some >particular points in a scene. Clearly, such a topic is interesting for a >computer vision system. Our feeling is that it is also of interest for >image synthesis: which will be the part in a synthetized picture that will >be scrutinized first? At the recent SPIE conf in San Jose someone (sorry, don't have my program with me) reported a study where they tracked the eye motions of people watching canadian TV. Since you only see well in the fovea, if you could send high-quality info only where, say, 99% of all people watched, you could save megabandwidth. BUt you need to predict this (set of) location; either with humans (tedious) or machines (unknown how to do this). >More generally, it would be very interesting to start a discussion on >how perceptual studies can be relevant to imaging sciences. This concerns >computer graphics as well as computer vision. The Eurographics Working >Group on the Relations between image analysis and image synthesis intends >focusing on issues of perception and it is open to interested researchers. >If there is enough interest, a mailing list could be started for exchanging >information. Interested people should contact one of the two persons >mentionned below. The whole reason that JPEG allows *you* to choose the quantization (as will MPEG) is so that *you* can implement what *you* think the human observer can/needs to see. The point was made at this conference that there are two kinds of redundancy you can exploit: image redundancy and the insensitivity of the human visual system. The latter gets at the importance of psychophysics. Cheers. -- David A. Honig "The fundamental principle of science, the definition almost, is this: the sole test of the validity of any idea is experiment." -- R. P. Feynman