<p dir="auto">I have run the cuda version of cascade classifier in OpenCV 2.4.11 on cpu and a 860M GPU. The results can be wildly different in terms of being accurate. To a point where a detected object that was found in CPU has the same rectangle size on GPU version, but in a location that is way off. I need to know if anyone has experienced this. If you have. Did you retrain the classifier on that GPU?</p>
<p dir="auto">I have tested my trained data(2.4.11) in OpenCV 2.4.11 cpu. I then was like well let me update the code base to use 3.2. Same, thing. Wildly different. Sometimes its correct sometimes it isn't.</p>
<p dir="auto">I'm using LPB and blasting full 1920x1080 images at it.</p>
<p dir="auto">This is a bug and a question.</p>
<h3 dir="auto">My system</h3>
<ul dir="auto">
<li>OpenCV version: 3.1</li>
<li>Host OS: Linux (Ubuntu 14.04)</li>
<li>CPU: intel i7 3770</li>
<li>Video card: GTX-950</li>
<li>Video driver: v.352.93</li>
</ul>
<h3 dir="auto">In which part of the OpenCV library you got the issue?</h3>
<ul dir="auto">
<li>objdetect, cudaobjdetect</li>
<li>cv::CascadeClassifier, cv::cuda::CascadeClassifier</li>
</ul>
<h3 dir="auto">Expected behaviour</h3>
<p dir="auto">I built the latest OpenCV version with cuda support from master branch. After that I tried to use CPU cv::CascadeClassifier and GPU cv::cuda::CascadeClassifier, but faced with a strange result. I use same xml from opencv/data/haarcascades_cuda/haarcascade_fullbody.xml for both CPU and GPU version of CascadeClassifier. CPU Classifier with this xml shows much more objects than GPU classifier.</p>
<p dir="auto">Another strange thing, that when I set ScaleFactor to 2, speed of CPU version boosted up to 4 times, but GPU version becomes just slightly faster.</p>
<h3 dir="auto">Additional description</h3>
<p dir="auto"><a href="http://answers.opencv.org/question/96452/different-results-of-cascadeclasifier-on-cpu-and-gpu/" rel="nofollow">OpencvQA</a><br>
<a href="https://github.com/Itseez/opencv/files/320887/example.ogv.zip">Video demo: example.ogv.zip</a><br>
<a href="https://github.com/Itseez/opencv/files/322422/example_v2.ogv.zip">Video demo with same parameters values: example_v2.ogv.zip</a></p>
<h3 dir="auto">Code example to reproduce the issue</h3>
<p dir="auto"><a href="https://bitbucket.org/barbatum/cascadeqa/raw/571cdafc1b230cb5ec5d2c7b6b766895549d2d1e/CascadeQA/main.cpp" rel="nofollow">Bitbucket: main.cpp</a><br>
<a href="https://bitbucket.org/barbatum/cascadeqa" rel="nofollow">Bitbucket: qmake project + deps build bash script</a></p>