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Questions tagged [viola-jones]

The Viola–Jones object detection framework is the first object detection framework to provide competitive object detection rates in real-time proposed in 2001 by Paul Viola and Michael Jones.

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Do I have to train Viola-Jones Algorithm with my database to obtain accurate results?

I try to extract facial features of a face database but I recognized that Viola-Jones algorithm is not working well* in two cases: When I try to detect the eyes singly, When I try to detect the mouth. *Not working well: Detects different parts of…
KMetin
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Face detection using Viola Jones in openCV

I am now comparing the time performance of Viola-Jones code between the one that is written in pure C code and one that uses openCV function cvHaarDetectObjects(). So far, it seems that the time it takes to detect faces with pure C code is about…
IKS
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Viola Jones Face Detection framework

I have just started studying the Viola-Jones face detection algorithm to design a face recognition system. off all the things i understood, I have confusion regarding the phrase:"sum of pixels". Does it means sum of colors at given pixels or the sum…
nkt217
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AdaBoost and Viola Jones: What training set to use?

I have implemented my own version of Viola Jones face recognition algorithm that uses AdaBoost as a meta for building a classification committee. My aim is to build a classifier that can recognize whether there is a human face in an image. I am…
Suppenkasper
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How to write Parallel ForEach in Viola-Jones

I want to speed up Viola-Jones by extracting detected face parallel, I use this code but there is an error in face argument within For Each statement, Can you tell me how to fix this error Please? the error is (Error 2 The type arguments for…
Hiraqi Hmaster
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Viola-Jones algorithm complexity

What is Viola-Jones algorithm complexity in form like O(log(N))? Even though it's a preety simple algorithm there is no concrete info about it.
Ilya Katanov
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Is there more detailed reference on Cascade Classifiers in OpenCV?

I'm trying to modify OpenCV's haar Cascade Classifier into specific purpose and looked into its source code from up to down. But I stuck on understanding very final part which is calculating feature value in line 361 of cascadedetect.hpp return…
BilguunCH
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Error in generating samples for trainCascadeObjectDetector in MATLAB

I was trying to train the cascade object detector in matlab with the 30 positive images with specified ROI and 10 negative images (without specified ROI). My code resembles with the matlab example code of 'Stop Sign Detector'. But when I tried to…
user3660102
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Haar-like features to detect objects

I was studying Viola-Jones paper for better understanding of their object detection algorithm and producing an applicable program. In the last paragraph of features' topic, authors talk about the base resolution of the detector which is 24x24, they…
Maryam
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Ideal images for Viola-Jones Haar cascade in OpenCV

I am trying to detect specific objects in images using Haar cascade in OpenCV. Let's say I am interested in detecting stop signs in landscape images. When defining positive image samples for my training set, which would be the best kind of image:…
rmf
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Face detection (viola-jones) in matlab

So I found the cascade object detector in matlab that use the Viola-Jones algorithm to detect faces. Very easy to use, and works great! But got a few questions. The viola-jones method got four stages: Haar Feature Selection Creating an Integral…
ToyMan
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Train cascade classifier

I got some questions about the training of a cascade classifier: On Some of my pictures half of the object is visible. Should I mark the visible part as region of interest, use the picture as negative sample or sort it out completely? Is the…
Phil
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How to get data for Matlab cascade Object Detector?

I want to use the trainCascadeObjectDetector in Matlab. It requires an array with the regions of interest of the images. I found two apps where you can put boxes around the rois and the array gets created automatically: Cascade Trainer: Specify…
Phil
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Confidence Scores for CascadeObjectDetector

I'm currently working on a project to explore various means of human detection. To formulate a base-line for comparison, I am looking to utilize several standard detection methods (ie, HOG with SVM, Viola-Jones). As I am using the Caltech…
ChrisD
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How to calculate detection_score for OpenCV's face detector?

I want to use FDDB to evaluate some face detectors including OpenCV. But FDDB's detection output file requires: It include a detection_score part. But the opencv's detector have no output like this. How…
tidy
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