How to find percentages of red, yellow, orange and green in an image?

I am doing image analysis on a few images of stained slides. I was hoping to find the percentage of the vessel that is red, green, yellow and orange. Any ideas on how to go about this? Thanks in advance for your help. As per a request, here's a link to the kind of picture I am dealing with. It is a picture of one of my stained slides.: http://tinypic.com/r/2mwi995/5 EDIT: for those that are interested, the differentiation of color allows us to determine the thickness of the collagen fibers. Each respective thickness has a different color. Any help would be appreciated

[Matt Kindig]

Could you upload a sample image? That would help us more than anything.

[Siddharth]

Hey Matt. The stains look somewhat like this http://www.google.com/imgres?imgurl=http://www.nature.com/labinvest/journal/v89/n3/images/journal_cover_large.gif&imgrefurl=http://www.nature.com/labinvest/journal/v89/n3/covers/index.html&h=791&w=600&sz=104&tbnid=9Y7Hb9POfv6e0M:&tbnh=102&tbnw=77&zoom=1&usg=__KE9nDLOH3IU_xyZiFYmnua89cj4=&docid=VMxbcY1h2HRbqM&sa=X&ei=UvHAUa3EJIbo9AS74YGYCg&ved=0CEYQ9QEwBA&dur=284

[Matt Kindig]

I meant, could you upload one of your slide images? You can upload an image to tinypic.com or similar, and edit your question to include the link. A solution that works for this image in Nature might not be appropriate for your slides, and if we could look at one of yours it would be better.

[Matt Kindig]

For a first step, I would take a look at the demos that Image Analyst has posted to File Exchange. That should get you familiar with the basic functions of interest.

http://www.mathworks.com/matlabcentral/fileexchange/26420-simplecolordetection

http://www.mathworks.com/matlabcentral/fileexchange/25157

http://www.mathworks.com/matlabcentral/fileexchange/28512

[Siddharth]

Hey Matt, I uploaded an image to tiny pic as per your suggestion. I have edited the question and I am looking at those links you posted as well. Thank you and if you have any other input or ideas let me know. Thank you again.

Answer 1

[random09983492]

Hi Siddharth,

I would take a look at the imread function build into Matlab. For an RGB image of size M-by-N, it will import the image as an M-by-N-by-3 Matrix, where red, green, and, and blue are separated into each Z dimension of the imported image.

[Siddharth]

Hey Elliot, Thank you for your response. I have been looking into the function that you mention, I am just having trouble getting started. I'll look into it a bit more, but if you have any other further suggestions please let me know. I posted a picture of the stained slides on the comment thread. Thanks again!