{"id":288,"date":"2013-07-22T14:43:47","date_gmt":"2013-07-22T14:43:47","guid":{"rendered":"http:\/\/www.giovannigualdi.com\/?page_id=288"},"modified":"2015-06-30T15:46:14","modified_gmt":"2015-06-30T15:46:14","slug":"fast-marker-detection","status":"publish","type":"page","link":"http:\/\/www.giovannigualdi.com\/?page_id=288","title":{"rendered":"Fast marker detection"},"content":{"rendered":"<p>What you can see in the video down here is the <span style=\"color: #993300;\">fast marker detection that I&#8217;ve developed for iOS (iPhone and iPad)<\/span>. The detection of 3D position and orientation of one or more markers can be used as a controller for a whole bunch of applications.<\/p>\n<p>In the video (poor quality, sorry!), you can see the detection going on by the white text just superimposed over the hand.<\/p>\n<div class=\"youtube\" style=\"width: 640; height: 482;\"><object width=\"640\" height=\"482\" classid=\"clsid:d27cdb6e-ae6d-11cf-96b8-444553540000\" codebase=\"http:\/\/download.macromedia.com\/pub\/shockwave\/cabs\/flash\/swflash.cab#version=6,0,40,0\"><param name=\"wmode\" value=\"transparent\" \/><param name=\"src\" value=\"http:\/\/www.youtube.com\/v\/n0SFQKKU81g&amp;rel=0&amp;hd=1\" \/><embed width=\"640\" height=\"482\" type=\"application\/x-shockwave-flash\" src=\"http:\/\/www.youtube.com\/v\/n0SFQKKU81g&amp;rel=0&amp;hd=1\" wmode=\"transparent\" \/><\/object><\/div>\n<p>This technique is very fast (@25fps on an iPad2!), ensuring extremely low latency on the \u00a0 controls that follow, and robust (very high SNR), especially in odd lightining conditions (low lights or sharp contrasts); it can be applied to many other use cases.<\/p>\n<p><span style=\"color: #993300;\">What about using marker detector + an accelerometer?<\/span> Check these two videos out; I&#8217;m using an iRing from IK Multimedia; <span style=\"color: #993300;\">the detection of the marker is plotted with red and green circles<\/span>: it is quite fast (30FPS, negligible CPU load) and looks robust I think; accelerometer is working at 100hz, you can see top left bars for X,Y,Z accelerations (cables you see here are used for the accelerometer only).\u00a0Hey there, I do not play guitar in life, so do not comment on it ok? =)<\/p>\n<div class=\"youtube\" style=\"width: 640; height: 480;\"><object width=\"640\" height=\"480\" classid=\"clsid:d27cdb6e-ae6d-11cf-96b8-444553540000\" codebase=\"http:\/\/download.macromedia.com\/pub\/shockwave\/cabs\/flash\/swflash.cab#version=6,0,40,0\"><param name=\"wmode\" value=\"transparent\" \/><param name=\"src\" value=\"http:\/\/www.youtube.com\/v\/EOICWcGhHIA&amp;rel=0&amp;hd=1\" \/><embed width=\"640\" height=\"480\" type=\"application\/x-shockwave-flash\" src=\"http:\/\/www.youtube.com\/v\/EOICWcGhHIA&amp;rel=0&amp;hd=1\" wmode=\"transparent\" \/><\/object><\/div>\n<div class=\"youtube\" style=\"width: 640; height: 480;\"><object width=\"640\" height=\"480\" classid=\"clsid:d27cdb6e-ae6d-11cf-96b8-444553540000\" codebase=\"http:\/\/download.macromedia.com\/pub\/shockwave\/cabs\/flash\/swflash.cab#version=6,0,40,0\"><param name=\"wmode\" value=\"transparent\" \/><param name=\"src\" value=\"http:\/\/www.youtube.com\/v\/iaLJUeF5mOs&amp;rel=0&amp;hd=1\" \/><embed width=\"640\" height=\"480\" type=\"application\/x-shockwave-flash\" src=\"http:\/\/www.youtube.com\/v\/iaLJUeF5mOs&amp;rel=0&amp;hd=1\" wmode=\"transparent\" \/><\/object><\/div>\n<p>I&#8217;d like to make it, but wirless&#8230; anyone interested out there?\u00a0<\/p>\n<p>This is another video, taken during the prototype development, where you can see the plot of the distance of the hand from the camera.<\/p>\n<div class=\"youtube\" style=\"width: 480; height: 360;\"><object width=\"480\" height=\"360\" classid=\"clsid:d27cdb6e-ae6d-11cf-96b8-444553540000\" codebase=\"http:\/\/download.macromedia.com\/pub\/shockwave\/cabs\/flash\/swflash.cab#version=6,0,40,0\"><param name=\"wmode\" value=\"transparent\" \/><param name=\"src\" value=\"http:\/\/www.youtube.com\/v\/w_LurfMwP3E&amp;rel=0\" \/><embed width=\"480\" height=\"360\" type=\"application\/x-shockwave-flash\" src=\"http:\/\/www.youtube.com\/v\/w_LurfMwP3E&amp;rel=0\" wmode=\"transparent\" \/><\/object><\/div>\n","protected":false},"excerpt":{"rendered":"<p>What you can see in the video down here is the fast marker detection that I&#8217;ve developed for iOS (iPhone and iPad). The detection of 3D position and orientation of one or more markers can be used as a controller &hellip; <a href=\"http:\/\/www.giovannigualdi.com\/?page_id=288\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"open","template":"","meta":[],"_links":{"self":[{"href":"http:\/\/www.giovannigualdi.com\/index.php?rest_route=\/wp\/v2\/pages\/288"}],"collection":[{"href":"http:\/\/www.giovannigualdi.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/www.giovannigualdi.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/www.giovannigualdi.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.giovannigualdi.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=288"}],"version-history":[{"count":19,"href":"http:\/\/www.giovannigualdi.com\/index.php?rest_route=\/wp\/v2\/pages\/288\/revisions"}],"predecessor-version":[{"id":296,"href":"http:\/\/www.giovannigualdi.com\/index.php?rest_route=\/wp\/v2\/pages\/288\/revisions\/296"}],"wp:attachment":[{"href":"http:\/\/www.giovannigualdi.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=288"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}