{"id":984,"date":"2018-01-28T01:07:35","date_gmt":"2018-01-28T01:07:35","guid":{"rendered":"https:\/\/ryma.cinvestav.mx\/ravg\/?post_type=project&#038;p=984"},"modified":"2018-01-28T01:27:58","modified_gmt":"2018-01-28T01:27:58","slug":"extended-photometric-analysis","status":"publish","type":"project","link":"https:\/\/ryma.cinvestav.mx\/ravg\/project\/extended-photometric-analysis\/","title":{"rendered":"Extended photometric analysis"},"content":{"rendered":"<p>In this case, shape analysis becomes a problem of inverting Lambert\u2019s law, i.e. the relationship between the surface normal and the light source direction causing an observed irradiance. The original ill-posed problem is known as shape-from-shading, however, when more than one light source is considered, new constraints allow numerical solutions to be included in the family of photometic stereo methods. I have been interested in studying the reflectance properties of both faces and diverse materials. My most recent research involves the development of a photometric stereo approach that is exclusive for face shape recovery, seeking for a coherent way to keeping facial proportions when estimating shape from several 2D images. This was one of the PhD contribution of former student, Dr. Felipe Hern\u00e1ndez-Rodr\u00edguez. Examples of facial shape recovery are shown in the following figure, where the recovered surface is imposed over an image of the profile picture of two subjects:<\/p>\n<p><strong>Selected\u00a0publications on this topic:<\/strong><\/p>\n<p>Felipe Hern\u00e1ndez-Rodr\u00edguez and\u00a0Mario Castel\u00e1n.\u00a0<strong><a href=\"http:\/\/link.springer.com\/article\/10.1007%2Fs00138-016-0755-9\">A photometric sampling method for facial shape recovery<\/a>.<\/strong>\u00a0\u00a0<em>Machine Vision and Applications, \u00a0<\/em>27 (4):\u00a0483-497 (2016).<\/p>\n<p>Mario Castel\u00e1n, Elier Cruz-P\u00e9rez and Luz Abril Torres-M\u00e9ndez.\u00a0<strong><a href=\"http:\/\/cys.cic.ipn.mx\/ojs\/index.php\/CyS\/article\/view\/1944\">A Photometric sampling strategy\u00a0for reflectance characterization and transference,<\/a><\/strong>\u00a0<em>Computaci\u00f3n y Sistemas,<\/em>\u00a019 (2)\u00a0: 255-272 (2015)<\/p>\n<p>Jocelyn Miranda-Hern\u00e1ndez,\u00a0Mario Castel\u00e1n\u00a0and Luz Abril Torres-M\u00e9ndez.\u00a0<a href=\"http:\/\/digital-library.theiet.org\/content\/journals\/10.1049\/iet-cvi.2011.0168\"><strong>Face colour synthesis using partial least squares and the luminance-a-b colour transform,<\/strong><\/a>\u00a0<em>IET Computer Vision,<\/em>\u00a06(4): 263-272\u00a0(2012).<\/p>\n<p>Felipe Hern\u00e1ndez Rodr\u00edguez and\u00a0Mario Castel\u00e1n.\u00a0<a href=\"http:\/\/www.bmva.org\/bmvc\/2012\/BMVC\/paper059\/index.html\"><strong>A method for improving consistency in photometric databases,<\/strong><\/a>\u00a0<em>Proc. British Machine Vision Conference,<\/em>\u00a01-1o (2012).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In this case, shape analysis becomes a problem of inverting Lambert\u2019s law, i.e. the relationship between the surface normal and the light source direction causing an observed irradiance. The original ill-posed problem is known as shape-from-shading, however, when more than one light source is considered, new constraints allow numerical solutions to be included in the [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":925,"comment_status":"open","ping_status":"closed","template":"","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"project_category":[18,17],"project_tag":[],"class_list":["post-984","project","type-project","status-publish","has-post-thumbnail","hentry","project_category-photometric-stereo","project_category-shape-analysis"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.3 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Extended photometric analysis - Robotics Active Vision Group<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/ryma.cinvestav.mx\/ravg\/project\/extended-photometric-analysis\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Extended photometric analysis - Robotics Active Vision Group\" \/>\n<meta property=\"og:description\" content=\"In this case, shape analysis becomes a problem of inverting Lambert\u2019s law, i.e. the relationship between the surface normal and the light source direction causing an observed irradiance. The original ill-posed problem is known as shape-from-shading, however, when more than one light source is considered, new constraints allow numerical solutions to be included in the [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/ryma.cinvestav.mx\/ravg\/project\/extended-photometric-analysis\/\" \/>\n<meta property=\"og:site_name\" content=\"Robotics Active Vision Group\" \/>\n<meta property=\"article:modified_time\" content=\"2018-01-28T01:27:58+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/ryma.cinvestav.mx\/ravg\/wp-content\/uploads\/sites\/19\/2017\/12\/MVAP1.png\" \/>\n\t<meta property=\"og:image:width\" content=\"806\" \/>\n\t<meta property=\"og:image:height\" content=\"400\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/project\\\/extended-photometric-analysis\\\/\",\"url\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/project\\\/extended-photometric-analysis\\\/\",\"name\":\"Extended photometric analysis - Robotics Active Vision Group\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/project\\\/extended-photometric-analysis\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/project\\\/extended-photometric-analysis\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/wp-content\\\/uploads\\\/sites\\\/19\\\/2017\\\/12\\\/MVAP1.png\",\"datePublished\":\"2018-01-28T01:07:35+00:00\",\"dateModified\":\"2018-01-28T01:27:58+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/project\\\/extended-photometric-analysis\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/project\\\/extended-photometric-analysis\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/project\\\/extended-photometric-analysis\\\/#primaryimage\",\"url\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/wp-content\\\/uploads\\\/sites\\\/19\\\/2017\\\/12\\\/MVAP1.png\",\"contentUrl\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/wp-content\\\/uploads\\\/sites\\\/19\\\/2017\\\/12\\\/MVAP1.png\",\"width\":806,\"height\":400},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/project\\\/extended-photometric-analysis\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Projects\",\"item\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/project\\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Extended photometric analysis\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/#website\",\"url\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/\",\"name\":\"Robotics Active Vision Group\",\"description\":\"Miembro de Rob\u00f3tica y Manufactura Avanzada - Cinvestav\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/ryma.cinvestav.mx\\\/ravg\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Extended photometric analysis - Robotics Active Vision Group","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/ryma.cinvestav.mx\/ravg\/project\/extended-photometric-analysis\/","og_locale":"en_US","og_type":"article","og_title":"Extended photometric analysis - Robotics Active Vision Group","og_description":"In this case, shape analysis becomes a problem of inverting Lambert\u2019s law, i.e. the relationship between the surface normal and the light source direction causing an observed irradiance. 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