title: Adaboost Cascade TPR and FPR
body: <p>When we use AdaBoost for object detection we need to set TPR and FPR for each stage (iteration of AdaBoost).</p>
  
  <p>We need high TPR and low FPR.</p>
  
  <p>As I understand as a result we have:</p>
  
  <p>total TPR = (stage1 TPR)<em>(stage2 TPR)...</em>(stageN TPR)</p>
  
  <p>for example 0.9*0.9*0.9~=0.729</p>
  
  <p>total FPR = (stage1 FPR)<em>(stage2 FPR)...</em>(stageN FPR)</p>
  
  <p>and same for FPR 0.5*0.5*0.5= 0.125</p>
  
  <p>So the more stages you use the lower FPR you get, but TPR also decrease.</p>
  
  <p>So why not to use stage TPR = 0.9999(9) and FPR = 0.00001 at each stage and have small number of stages?</p>
  
  <p>How TPR and FPR at each stage must be choosed? How it dependes on number of stages?</p>