how do i extract the color of the person(red)

Here's the image http://ppl.ug/RvsGhUC9afo/

Answer 1

[Image Analyst]

That's a thermal image. You should not want the color of the person - that's just some arbitrary color map (pseudocolor look up table) that's been applied. What you should want is the temperature of the person, and for that you should get the original grayscale thermal image. Upload the original thermal image and then we can proceed.

[dinie matin]

this is an original image..i dont know how to extract the image to get only the heat and remove the background

[Image Analyst]

You think it's the original image, but I guarantee you , it's not. I've worked with thermal images for years. There is a grayscale thermal image that formed the basis of that.

Nonetheless, if you want to work with the pseudocolored image, see the red detecting application in my File Exchange: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862