At first I thought this was a duplicate to http://www.mathworks.com/matlabcentral/answers/16625-how-to-extract-r-g-b but I already gave an answer there and you responded, so I know you saw that.
But now I see that you're asking how to upload an image. Strange. You already uploaded an image and now you're asking how to upload an image. Well the answer is: http://www.mathworks.com/matlabcentral/answers/7924-where-can-i-upload-images-and-files-for-use-on-matlab-answers
But I guess the weirdest thing is that what you asked in your subject line doesn't seem to agree with what you asked in the body of your message. You do know that upload and extract mean two entirely different things, don't you?
