{"id":40191,"date":"2019-12-03T07:05:32","date_gmt":"2019-12-03T07:05:32","guid":{"rendered":"http:\/\/www.labri.fr\/perso\/barla\/blog\/?p=40191"},"modified":"2019-12-03T07:05:34","modified_gmt":"2019-12-03T07:05:34","slug":"distortion-patterns","status":"publish","type":"post","link":"https:\/\/www.labri.fr\/perso\/barla\/blog\/?p=40191","title":{"rendered":"Distortion patterns"},"content":{"rendered":"<p id=\"top\" \/>\n<h3 class=\"wp-block-heading\">Breaking the spell<\/h3>\n\n\n\n<p>Deformed patterns could be entirely 2D (marbling) or 3D (reflections  from bumpy object).How do we make the difference: In a single image ? With  (reversible) motion ? <br>Abundance of concomitant invariants makes it hard to understand what  matters to perception. Progressively removing ecologically available cues helps &#8220;break the  spell&#8221; of a 3D percept. Removing silhouettes, disallowing reversibility in motion, moving  orthogonal to max curvature direction. <\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Direction &amp; polarity<\/h3>\n\n\n\n<p>Reflections off shiny objects are deformed, which indicate curvature;  but only direction field matters, not gradient field. <br>Polarity is often important: in glossy objects, highlights are white. But it might be ignored, as with metallic objects where both  white-on-dark or dark-on-white are valid (photography). <br>This is because direction ALWAYS specifies something important,  polarity sometime does, and magnitude rarely so. <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Breaking the spell Deformed patterns could be entirely 2D (marbling) or 3D (reflections from bumpy object).How do we make the difference: In a single image ? With (reversible) motion ? Abundance of concomitant invariants makes it hard to understand what matters to perception. Progressively removing ecologically available cues helps &#8220;break the spell&#8221; of a 3D &#8230; <a title=\"Distortion patterns\" class=\"read-more\" href=\"https:\/\/www.labri.fr\/perso\/barla\/blog\/?p=40191\" aria-label=\"Read more about Distortion patterns\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[772],"tags":[],"class_list":["post-40191","post","type-post","status-publish","format-standard","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/40191","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=40191"}],"version-history":[{"count":1,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/40191\/revisions"}],"predecessor-version":[{"id":40192,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/40191\/revisions\/40192"}],"wp:attachment":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=40191"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=40191"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=40191"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}