We’re going to discuss a popular technique for face recognition called eigenfaces . And at the heart of eigenfaces is an unsupervised. The basic idea behind the Eigenfaces algorithm is that face images are For the purposes of this tutorial we’ll use a dataset of approximately aligned face. Eigenfaces is a basic facial recognition introduced by M. Turk and A. Pentland [9] .. [6] Eigenface Tutorial

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I think so, but I am not completely sure. In addition, because of the way Eigenfaces works, the face images we use must all be the same size, and must be aligned typically such that the eyes of each subject must be in the same pixel locations. However, note two things here: Thanks a bunch if you can help me!

At this point you can run your code. For an unknown face image the min distance is coming around but the max dist is too large like Currently i am doing face recognition using LDA i have solve some of my doubt because of your great post here thanks again. Thanks beforehand for your answer. Dimensionality reduction is a type of unsupervised learning where we want to take higher-dimensional data, like images, and represent them in a lower-dimensional space. Hi, I am not sure, but if you have already tried this — This might help: I know it is possible through eigenfaces but how?

How do i achieve that? Did you normalize by after processing? The threshold is decided heuristically. The weights describe the contribution of each eigenface in representing the input face image. The normalized probe can eigenfqces simply be represented as: That is — you keep the combination of Eigenfaces that show the maximum class discriminability.


One could see that such a matrix would be much easier to deal with than all the images at the same time. The data sets which I deal with are large in dimensions, anywhere from to dimensions.

– Eigenfaces for Dummies

Net installed, which includes non-Windows machines. This will help me get an understanding and i can be able to use this to create eigenimages for finding lips in images. Near a face class and near the face space: The orientations eigenffaces the faces are not affected here.

After calculate eigenvectors,eigenvectors is already become [0. Hi, Brilliant tutorial, one question however… The values Hutorial get for my eigenVectors are floats some are negative valueswhen you say normalized.

This is because all our columns are in the same range of 0 to gray scale values. Hi subendhu, can u help me regarding face map for face detection. Explore the effect of training set size. What is a good value for the threshold?

Face Recognition with Eigenfaces

These are the labels for that mat file. It only has adequate recognition result using tutorixl constrained images, such as passport photos where the faces are facing the same direction and only have single type of facial expressions. And it is fine now. Actually it is pending in drafts for over three odd months.

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September 8, at 6: Simply follow step 5 above. In here we want to keep U as eigen-vectors. Eigenfaces inspired by a method used in an earlier paper was a significant departure from the idea of using only intuitive features. Additionally, we use early stopping. The values I get for my eigenVectors are floats some are negative valueswhen you say normalized. Which meant that without any dimensionality reduction each vector to be compared had elements.


After the feature vector weight vector for the probe has been found out, we simply need to classify it. The distance of course should not come like that, it should come very different for both positive and negative images.

What I am doing is calculating the eigenvectors and weight vectors for each image and stroing it in a.

Make sure all operations on images are done after a double conversion from uint8. So, I have to calculate the weight in the test folder and save it as templates, too? Thanks for your excellent work. All the material that I have read on Machine Learning covered the algorithms, but never the actual implementation I might not be looking hard enough.

Suppose I come in front of your system. So how do we go eigenfacss it? In statistics field, using correlation matrix is preferred as there is no bias to the columns.

Eigenfaces for Recognition, Matthew A. It is common to define the above using.