Retrieval and Ranking of Biomedical Images using Boosted Haar Features

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Image Analysis and Interpretation 28/06/13 Melanie Torres Bisbal

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Presentation and summary of the paper: Retrieval and Ranking of Biomedical Images using Boosted Haar Features, Chandan K. Reddy and Fahima A. Bhuyan Abstract of the paper: Abstract— Retrieving similar images from large repository of heterogeneous biomedical images has been a difficult research task. In this paper, we develop a retrieval system that uses Haar features as its weak classifiers and builds strong training models using the adaboost algorithm. Our system is trained for each image category separately and the final boosted model is stored during the training phase. In the test phase, the most similar images for a given query image are computed using these boosted models. The main advantages of the proposed system are (1) cheap computation of the most relevant features for each image category and (2) fast retrieval of similar images for a given query image. Using performance metrics such as sensitivity and specificity, our results demonstrate the robustness and accuracy of the proposed system.

Transcript of Retrieval and Ranking of Biomedical Images using Boosted Haar Features

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Image  Analysis  and  Interpretation  28/06/13  Melanie  Torres  Bisbal  

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¡  Ranking  and  retrieval  of  medical  images  ¡  Retrieve   information   from   a   database   that   the  images  are  similar  is  much  difficult  

¡  Paper   proposed   a   new   algorithm   with   the  following  concepts:  §  Integral  image  §  Haar  like  features  §  Adaboost  

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¡  Extracting  and  understanding   the   structure  and  characteristics  of  medical  images  is  challenging  

¡  A   typical   radiology   department   generates  between  100,000  to  10  million  images  per  year  

¡  Applications  in  the  detection  and  classification  ¡  Also  specific  applications  in  image  retrieval  with  pulmonary  nodules  

¡  Retrieve  and  sort  the  information  in  real  time  

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¡  Since  80  has  been  a  research  topic  ¡  But  the  field  of  biomedical  imaging  is  in  a  very  early  stage  

¡  Images  to  train  and  test  the  proposed  algorithm  are  taken  from  the  database  of  IRMA  (Image  Retrieval  in  Medical  Applications)  

¡  Use  a  subset  of  images  to  train  the  different  categories  and  remove  Haar-­‐like  features  to  build  specific  models  

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¡  One  of  the  biggest  problems  is  precisely  recover  the   characteristics   that   define   the   visual  similarity   of   the   anatomical   structure   of   the  different  categories  

¡  Generally   have   used   co-­‐occurrence   matrix   of  gray,  Gabor  filters,  etc..  

¡  In   this   paper   are   based   more   on   reducing   the  time  a  given  question  (query)  

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¡  Haar-­‐like  features,  proposed  by  Viola  and  Jones  ¡  Two  advantatges:  

§  The  system  can  be  used  for  a  wide  range  of  biomedical  image  retrieval  as  a  tumor  

§  Recovery  time  it  takes  significament  is  low  in  comparison  to  other  methods  

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¡  The   key   steps   to   construct   the   algorithm  described  in  the  paper  are:  §  Efficient  extraction  of  simple  wavelets  (Haar)  §  Train  the  boosting  algorithm  applied  to  each  category  §  Calculate  the  closest  similarity  given  a  query  

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¡  Efficient  computation  from  Integral  Image  ¡  In   this   paper   implemented   using   the   Intel  OpenCV  @:  

¡  The  features  are:  

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¡  In  the  training  phase  boosting  applied  to  each  separate  category  to  find  the  weights  and  the  weak  classifiers  

¡  For  a  query  in  the  test  phase  the  system  will  identify  the  class  it  belongs  to  and  return  the  top  ranking  images  repository  

¡  To  look  at  the  results  is  calculated:  

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¡  Chandan  K.  Reddy  and  Fahima  A.  Bhuyan,  Retrieval  and  Ranking  of  Biomedical  Images  using  Boosted  Haar  Features  http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4696834&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4696834