feature vectorsf or histogram

I want to classify normal and abnormal images..I m having histogram as a features for normal and abnormal images.. How can i compute the feature vectors for these histograms... please anyone help me ..

thanks in advance

Answer 1

[Image Analyst]

This is somewhat unclear. First you say that the histograms are the features. Then you ask how to compute features for histograms. Are the histograms the features, or do you want to start with the histograms and derive features from them (such as [mean, stddev, skew, kurtosis])?

Anyway, once you've answered that, how about using imhist() to compute the histograms? Then you're either done (if the histograms themselves are the features) or you need additional steps to derive features from the histograms.

[Image Analyst]

If they say the whole entire histogram is one feature, then just use it as such. Normally a feature vector is something more meaningful, like a list of histogram moments like I said above: [mean, stddev, skew, kurtosis]. That would be a 4 element feature vector. It has 4 features, which are the 1st, 2nd, 3rd, and 4th moments of the histogram. A feature vector is just a list of various measurements that you make and they could be anything, like number of regions, mean intensity of the regions, mean area of the regions or all the areas of all the regions. It could be anything you want because you are the one who is going to be processing them in some what that makes sense for you. You should know what to do with them - there is not one overall way to manipulate a feature vector, it depends on what you want to do with the numbers.

Answer 2

[jenifer]

s sir.. in my paper they said histogram as features...using these histogram features how can i train and test the images... then wt about feature vectors?..pls exlain me sir...

thanks in advance.

[Image Analyst]

I'll respond under my answer, where you should have placed this - since it's a comment, not an answer to your question.

Answer 3

[jenifer]

sir i m applying edge histogram descriptor to extract the edge features... I abtained 80 bin histogram as features.... can i compute mean or standard deviation for histogram...

[Image Analyst]

Is this an "Answer" to your Question? You posted it as an "Answer".