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FaceRecognition Class

asked 2012-09-11 14:43:41 -0500

Dreyk gravatar image

Hi, I'am develop a FaceRecognizer on iOS. And I've a doubt, the Face Recognition algorithm in the class need a pre processing? Or the class do that for me?

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answered 2012-09-11 16:01:30 -0500

updated 2012-09-11 16:21:55 -0500

For the current algorithms you have to pass your input images as grayscale. You can use cv::cvtColor to convert color images into their grayscale representation:

Algorithms like Eigenfaces and Fisherfaces require your training data to be of equal size. You can use cv::resize to resize your images:

Pay special attention to the documentation on cv::FaceRecognizer at:

Just look at the full source code listing on "Face Recognition in Videos" for example, because all preprocessing is done in there, too.

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Thank for the answer. But my question was if I need, I don't know, equalize the histogram, applied a filter like a Gaussian or Median. Is needed pre processing the image like that?

Dreyk gravatar imageDreyk ( 2012-09-11 23:59:17 -0500 )edit

No, it is not needed.

Philipp Wagner gravatar imagePhilipp Wagner ( 2012-09-12 01:02:58 -0500 )edit

Thank Philipp. So, I don't know why the recognizer is bad... The only improvement I can think of is to rotate the picture as the eyes.

Dreyk gravatar imageDreyk ( 2012-09-12 13:23:50 -0500 )edit

I am working on some algorithms for head pose estimation, but there's nothing I can release yet. Keep an eye on my blog,

Philipp Wagner gravatar imagePhilipp Wagner ( 2012-09-12 13:36:03 -0500 )edit

Thank! I'll remove all the pre processing because that reduce the performance and is not needed. I'm going to rotate the face like the eyes and then use the FaceRecognizer with the Fisherface algorithm. I'm using a threshold of 300, maybe I can reduce that.

Dreyk gravatar imageDreyk ( 2012-09-12 15:00:28 -0500 )edit
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Asked: 2012-09-11 14:43:41 -0500

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Last updated: Sep 11 '12