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Questions tagged [haar-wavelet]

In mathematics, the Haar wavelet is a sequence of rescaled "square-shaped" functions which together form a wavelet family or basis. They are similar to techniques used in facial recognition.

In mathematics, the Haar wavelet is a sequence of rescaled "square-shaped" functions which together form a wavelet family or basis. Haar-like features are digital image features used in object recognition. They owe their name to their intuitive similarity with Haar wavelets and were used in the first real-time face detector.

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Haar Cascaded Classifier Data in OpenCV:

I can't find any information about Data used for training Haar classifiers in OpenCV. I want to know what kind of, how many and how(manually or via program) these classifiers were generated. You can find these classifier's xml files in…
Saleh
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CDF 9/7 Discrete Wavelet Transform (Convolution)

I'm trying to write a simple self-contained program that does a single level of a discrete wavelet transform on a 1D list, using the CDF 9/7 wavelets, and then reconstructs it. I'm just using the convolution/filter-bank method to get a grasp on how…
Andrew
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What are Haar Pyramids?

I'm trying to reproduce (part of) the work in this paper: http://www.mit.edu/~kimo/publications/harmonization/ I can't figure out quite what they mean by "Haar pyramids". I've found all kinds of things on the Gaussian and Laplacian image pyramids,…
sapphiremirage
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How to Display wavelet transformation function dwt2 results in matlab

I am applying dwt2 function on an image to apply wavelet transformation which is giving four result images cA(low pass image),cH (Horizontal Detail image),cV(Vertical Detail Image),cD (Diagonal Detail Image). Every this fine till Now. I want to…
saimadhu.polamuri
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Weak vs Strong descriptors - machine vision

I have heard of Haar-like features being described as weak descriptors and that the Adaboost method is advantageous over SVM in this case because of this. My question is what is a weak descriptor and strong descriptor and why does a boosting method …
Colin747
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Is this wavelet transform implementation correct?

I am searching for alternatives to the FFT to create a spectrogram analyser in python. I heard that the wavelet transform is faster and provides better time accuracy than the short time FFT. I went in this wikipedia article that features the Haar…
user2464424
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Facial feature detection with OpenCV with eyes and mouth corners points

I'm working on a face feature detection project and I do detect the eyes, nose and mouth using OpenCv withHaarcascade xml files. But, I want to have the eyes and mouth corners points and the nose center. The goal is using it to predict emotions. I…
user2425049
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How to compute Inverse Stationary Wavelet Transform of an Image?

I understand the forward Stationary Wavelet Transform and how it is implemented on the diagonal, vertical and horizontal components. In fact, I have it implemented. What I don't understand is what exactly is the algorithm to compute Inverse…
user1343318
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Infinite loop in opencv_traincascade CvCascadeClassifier::fillPassedSamples

So I have been playing around with opencv's newest LBP cascade trainer, and I keep running into infinite loop. I believe the reason may be caused by my limited negative (background) image set. However the program should not run into infinite loop...…
Joe Qi
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How to draw a haar wavelet plot using pywt?

I'm only in the beginning of learning wavelet transformation, so I have such naive question. I have quite simple scaling function with only two non-zero coefficients: h(0) = h(1) = 1/ sqrt(2) I have calculated the average and difference part on…
Daniel Chepenko
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Ear detection using opencv

I am trying to detect ears in a profile image(side view) of face.I tried using harrcascades (haarcascade_mcs_rightear,haarcascade_mcs_leftear,left_ear.xml,right_ear.xml) provided in opencv.I am able to detect profile face.But I am not able to detect…
algorithmic
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Error trying to detect faces in an image with OpenCV JAVA

I have used the code from this tutorial: http://opencvlover.blogspot.co.uk/2012/11/face-detection-in-javacv-using-haar.html It has been slightly modified to read a different image, and display this image before attempting face detection (line 14).…
dahui
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Implementing Discrete Wavelet Transformation in C

I am trying to implement DWT on gray images in C++. I saw an OpenCV implementation at https://stackoverflow.com/a/20072775/3024435. The article at http://www.whydomath.org/node/wavlets/hwt.html was useful in understanding and implementing low/high…
user3024435
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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
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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
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