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.
Questions tagged [viola-jones]
90 questions
2
votes
1 answer
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
- 4,747
- 9
- 49
- 89
2
votes
0 answers
Using Haar features for cascade object detector MATLAB
I am trying to use the vision.cascadeObjectDetector (MATLAB) to detect heads from a CCTV footage(and not faces). Till now, I have tried the following:
Used vision.cascadeObjectDetector to detect faces.
trained it to detect a sign (an example shown…
user2541516
- 79
- 1
- 9
2
votes
2 answers
Real time face detection using Viola and Jones in MATLAB
I am looking to detect faces in real time video captured from laptop camera. I use MATLAB R2011a (not the latest one) which does not have any Cascade Object Classifier function to identify face detection.
I have used a package…
Iamcool
- 1,387
- 2
- 12
- 24
2
votes
1 answer
Face Detection with using Computer Vision Toolbox(Viola Jones) in Matlab
I have a final project about face detection. I decided to do this project using Matlab and the Computer Vision Toolbox because as you know, this toolbox uses Viola Jones Algorithm for object detection.
I wrote the code below but the code matches a…
yigitcannalci
- 23
- 1
- 5
2
votes
2 answers
Viola - jones adaboost method
I have read the paper about Viola-Jones method for object detection and am confused by a few things.
1 - For Adaboost does each round mean that we calculate all the 160k features across all images then find the one with the least error (which as i…
medz91
- 105
- 3
- 13
2
votes
1 answer
What if each round of boosting selects same Haar-feature in Viola-jones face detection method?
I am implementing Viola-Jones face detection to detect human faces. While training using Adaboost, boosting round selects the same haar feature. For example, if the selected Haar-feature (x,y,w,h,f,p) for the first three round is (0,0,4,2,1,0) ,…
user2766019
- 577
- 4
- 7
- 20
2
votes
1 answer
How Viola-Jones face detector work for multiple size of faces?
I am implementing Viola-Jones face detector to detect faces in still images and it work preety for images having same size as of my training size. However I am not getting how the face detector work for multiple size faces?
If the training size of…
user2766019
- 577
- 4
- 7
- 20
2
votes
1 answer
Viola Jones AdaBoost running out of memory before even starts
I'm implementing the Viola Jones algorithm for face detection. I'm having issues with the first part of the AdaBoost learning part of the algorithm.
The original paper states
The weak classifier selection algorithm proceeds as follows. For each…
robev
- 1,909
- 3
- 23
- 32
2
votes
1 answer
Viola-Jones detection algorithm using OpenCV haarcascade xml
I am trying to implement Viola Jones detector. Because I don´t have enough images or time to train classifiers, I decided to use these OpenCV has.
So far, I was able to load whole haarcascade_frontface_alt.xml into structures in memory, create…
B.Gen.Jack.O.Neill
- 8,169
- 12
- 51
- 79
1
vote
1 answer
viola jones algorithm clarification
As mentioned in the paper, while training the classifier 24x24 images are used.
But for face detection on image of size 1024x1600 which contains face of size 500x500 how is the face detected if we are using 24x24 windows to detect face?
hrithik mahesh
- 93
- 9
1
vote
1 answer
How to detect multiple faces from the same image?
I am trying to crop multiple faces from the same image using python and opencv but it is showing me error.
If there is any other way of doing it please let me know.
Below is the code along with the error.
import cv2
# Load some pre-trained data on…
Anik Alvi
- 13
- 3
1
vote
1 answer
Computing all the Haar-like features using scikit-image
How can we compute all the Haar-like features of all types using scikit-image function haar_like_feature? This is what I have tried (a simple example for computing all the features of type 2x):
from skimage.feature import haar_like_feature
from…
Andreas K.
- 9,282
- 3
- 40
- 45
1
vote
0 answers
Object is Currently in use elsewhere!!!! how can i fix it?
Please I have problem in this program
Error appear (Object is currently in use elsewhere)and (Bitmap region is locked)"if you are using the graphic object after the gethdc method call the releasehdc method"
I am trying to detect faces using Viola…
Hiraqi Hmaster
- 37
- 2
1
vote
1 answer
Is there a way to detect a face with opencv without using viola-jones algorithm?
Is there a way to detect a face using opencv without using viola-jones algorithm?
Erick Campos
- 13
- 4
1
vote
0 answers
How do I calculate the feature scaling in Viola Jones algorithm?
I'm confused about how to calculate feature scaling in Viola Jones algorithm. For example in "An Analysis of the Viola-Jones Face Detection Algorithm" of Yi-Qing Wang, he proposed the following for feature type "a":
set the original feature support…
Germán Lescano
- 11
- 2