{"id":23646,"date":"2021-05-14T11:14:47","date_gmt":"2021-05-14T15:14:47","guid":{"rendered":"https:\/\/www.bu.edu\/hic\/?p=23646"},"modified":"2021-05-14T14:16:10","modified_gmt":"2021-05-14T18:16:10","slug":"a-real-time-change-detection-algorithm","status":"publish","type":"post","link":"https:\/\/www.bu.edu\/hic\/2021\/05\/14\/a-real-time-change-detection-algorithm\/","title":{"rendered":"A Real-Time Change Detection Algorithm"},"content":{"rendered":"<p>BY GINA MANTICA<\/p>\n<p>Robots navigate around a room thanks to cameras and algorithms that help them process images. But, as a robot starts moving around, so does the camera\u2019s field of view. To control a robot\u2019s movements and prevent it from crashing into objects, it needs to excel at change detection \u2013 or the process of finding differences between frames of a video when returning to the same location (e.g., a new box on the floor).<\/p>\n<figure id=\"attachment23666\" aria-describedby=\"caption-attachment23666\" style=\"width: 210px\" class=\"wp-caption alignright\"><img loading=\"lazy\" src=\"\/hic\/files\/2021\/05\/photo-Ishwar-636x636.png\" alt=\"\" width=\"200\" height=\"200\" class=\"wp-image-23666\" srcset=\"https:\/\/www.bu.edu\/hic\/files\/2021\/05\/photo-Ishwar-636x636.png 636w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/photo-Ishwar-150x150.png 150w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/photo-Ishwar-768x768.png 768w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/photo-Ishwar-700x700.png 700w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/photo-Ishwar-189x189.png 189w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/photo-Ishwar-100x100.png 100w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/photo-Ishwar.png 900w\" sizes=\"(max-width: 200px) 100vw, 200px\" \/><figcaption id=\"caption-attachment23666\" class=\"wp-caption-text\">AIR Affiliate Prakash Ishwar said that their algorithm can be applied to a variety of background-subtraction datasets used by researchers.<\/figcaption><\/figure>\n<p><a href=\"https:\/\/www.bu.edu\/hic\/centers-initiatives-labs\/air\/\">Artificial Intelligence Research Initiative<\/a> affiliates Janusz Konrad and Prakash Ishwar, along with PhD student Ozan Tezcan, developed a supervised deep learning algorithm that automatically finds changes in a video even in complex scenarios that don\u2019t exist in the dataset that the algorithm is trained on. The algorithm can be used as the first step in more complex computer vision and video processing tasks to allow real-time object classification and tracking. Their findings were recently published in <a href=\"https:\/\/ieeexplore.ieee.org\/document\/9395443\"><em>IEEE Access<\/em><\/a>.<\/p>\n<figure id=\"attachment23649\" aria-describedby=\"caption-attachment23649\" style=\"width: 143px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" src=\"\/hic\/files\/2021\/05\/Konrad_2015_2_600x900-424x636.jpg\" alt=\"\" width=\"133\" height=\"200\" class=\"wp-image-23649\" srcset=\"https:\/\/www.bu.edu\/hic\/files\/2021\/05\/Konrad_2015_2_600x900-424x636.jpg 424w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/Konrad_2015_2_600x900-240x360.jpg 240w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/Konrad_2015_2_600x900.jpg 600w\" sizes=\"(max-width: 133px) 100vw, 133px\" \/><figcaption id=\"caption-attachment23649\" class=\"wp-caption-text\">AIR Affiliate Janusz Konrad was part of a team that developed a supervised deep learning algorithm to automatically finds changes in a video.<\/figcaption><\/figure>\n<p>The ability of a computer to detect meaningful changes in a video happens through a process called background subtraction. \u201cIn Computer Science, background subtraction is an ancient and well-researched problem,\u201d said Konrad. Early methods assumed a single background and \u201csubtracted\u201d it from the current video frame, but this approach works only in the simplest scenarios. In more complex videos, the backgrounds of videos are difficult to determine. For example, many background subtraction methods cannot determine accurately whether a car stopping on the road for several minutes or the leaves of trees swaying in the wind should be considered as part of the background.<\/p>\n<p>To improve how well the algorithm detects changes in videos, Tezcan not only used many different types of video backgrounds to train the algorithm, but also multiple versions of the same background. Videos of highways, parks, offices, homes, and parking lots were altered to increase the amount of data used to train the algorithm. \u201cWe used a process called data augmentation, where we create new data from an <a href=\"http:\/\/changedetection.net\/\">existing dataset<\/a>. We transformed videos to create pan effects, tilts, and zooms,\u201d said Ishwar. The researchers also changed the lighting and chose videos taken in different weather conditions to diversify their dataset further. Training the algorithm on these \u201caugmented backgrounds\u201d, as Tezcan put it, is what makes their algorithm, BSUV-Net 2.0, unique and applicable to all sorts of videos.<\/p>\n<p>Previous supervised background subtraction algorithms relied upon having access to at least some manually-annotated frames of the same video on which they were tested, rendering them impractical. But the BU team created a \u201cplug and play\u201d algorithm that can be used on unseen videos without requiring annotations. \u201cThe novelty of our algorithm is in the inputs and augmentations,\u201d said Ishwar, \u201cWhen we apply our algorithm to a variety of background-subtraction datasets used by researchers, it generalizes well.\u201d<\/p>\n<figure id=\"attachment23667\" aria-describedby=\"caption-attachment23667\" style=\"width: 171px\" class=\"wp-caption alignright\"><img loading=\"lazy\" src=\"\/hic\/files\/2021\/05\/Ozan-Tezcan-photo-512x636.jpg\" alt=\"\" width=\"161\" height=\"200\" class=\"wp-image-23667\" srcset=\"https:\/\/www.bu.edu\/hic\/files\/2021\/05\/Ozan-Tezcan-photo-512x636.jpg 512w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/Ozan-Tezcan-photo-825x1024.jpg 825w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/Ozan-Tezcan-photo-768x953.jpg 768w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/Ozan-Tezcan-photo-1238x1536.jpg 1238w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/Ozan-Tezcan-photo.jpg 1543w\" sizes=\"(max-width: 161px) 100vw, 161px\" \/><figcaption id=\"caption-attachment23667\" class=\"wp-caption-text\">PhD student Ozan Tezcan used data augmentation to improve their algorithm.<\/figcaption><\/figure>\n<p>The algorithm\u2019s performance and speed lend it to a variety of applications &#8212; from surveillance and law enforcement, to robots and smart technologies. \u201cWhat was interesting is that Ozan modified the algorithm to run very fast, at video rates. There may be a use for this in real-time applications of the algorithm,\u201d said Konrad.<\/p>\n<p><a href=\"https:\/\/github.com\/ozantezcan\/BSUV-Net-inference\">For access to the open-source algorithm, click here<\/a>.<\/p>\n<figure id=\"attachment23662\" aria-describedby=\"caption-attachment23662\" style=\"width: 646px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" src=\"\/hic\/files\/2021\/05\/bsuvnet2-cover-photo-636x284.jpeg\" alt=\"\" width=\"636\" height=\"284\" class=\"size-medium wp-image-23662\" srcset=\"https:\/\/www.bu.edu\/hic\/files\/2021\/05\/bsuvnet2-cover-photo-636x284.jpeg 636w, https:\/\/www.bu.edu\/hic\/files\/2021\/05\/bsuvnet2-cover-photo.jpeg 660w\" sizes=\"(max-width: 636px) 100vw, 636px\" \/><figcaption id=\"caption-attachment23662\" class=\"wp-caption-text\">Visual comparison of the proposed algorithm with state of the art (SOTA).<\/figcaption><\/figure>\n<hr \/>\n<p><em>Interested in learning more about the transformational science happening at the Hariri Institute?\u00a0<a href=\"https:\/\/www.us6.list-manage.com\/subscribe?u=e3ad8f42733d54531fb729327&amp;id=d2da4f4d79\">Sign up for our newsletter here.<\/a><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>BY GINA MANTICA Robots navigate around a room thanks to cameras and algorithms that help them process images. But, as a robot starts moving around, so does the camera\u2019s field of view. To control a robot\u2019s movements and prevent it from crashing into objects, it needs to excel at change detection \u2013 or the process [&hellip;]<\/p>\n","protected":false},"author":8550,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[11791,11716,1],"tags":[],"_links":{"self":[{"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/posts\/23646"}],"collection":[{"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/users\/8550"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/comments?post=23646"}],"version-history":[{"count":4,"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/posts\/23646\/revisions"}],"predecessor-version":[{"id":23668,"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/posts\/23646\/revisions\/23668"}],"wp:attachment":[{"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/media?parent=23646"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/categories?post=23646"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bu.edu\/hic\/wp-json\/wp\/v2\/tags?post=23646"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}