classification images using knn

hi, I have some questions about knn. I have 2 different class of dogs and cats and I want to classify new images based on their class.I want to use knn in matlab but I do not know how to use it, because the example in knn's help is a vector but I work with image(matrices). please help me how can I provide knn inputs?

Answer 1

[Image Analyst]

MATLAB has a webinar for a cat/dog detector: http://www.mathworks.com/videos/deep-learning-for-computer-vision-with-matlab-116080.html?s_tid=srchtitle It uses computer vision to identify a subimage with the animal in it, then it uses deep learning to classify the animal as either a cat or a dog.

[nadia]

Thanks for your answer but I want to know how to use knn.I think I should reshape each image to vector and then compare them. Is it true?

[Image Analyst]

No, of course not. How could that work? Only if it were something like you're looking at gray levels and all your cats were black and all your dogs were white, but that's a very very restricted case and not robust at all.

If you just want to learn and use knn, try some of the demos out there that work well with it, rather than trying some situation where it won't work well.