Producing Graphical map of Image intensity via dual-ROI, utilizing baseline ROI

Hello, Before I present my question, I'd like to make it clear that I am very new in the Matlab field, and so there is a lot of concepts and commands that I am unfamiliar with. That said, I am very eager to learn what specifically I need to do, and have already looked in the online resources to try to answer my question before I've came to the actual community.

Presented below is essentially what I'm attempting to make:

These series of images are a linear progression of image intensity as a function of temperature, and were provided to us by a collaborator whom analyzed our results. From what I understand, they were able to take a baseline image in grayscale such as the one provided below

And as you can (hopefully) tell, there are two circles present in the image, which can be used as a baseline, and then via subtracting the difference between the baseline and all images hereafter.

That is the procedure I am hoping to obtain, and receive a result such as the first image I posted, however if it is easier to obtain just a numerical value for the sphere, rather than an imaged map such as the one posted, that can be sufficient too.

I hope my request for help doesn't seem like I'm asking for somebody to do it for me, as I'm eagerly wanting to learn these commands and techniques; however I feel that this is a rather daunting task in regards to my inexperience.

Please let me know if there's any other questions I can answer, and I'll be happy to! Thank you very much!

Answer 1

[Image Analyst]

First of all, run my image segmentation tutorial: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

Next, stitch all your images together and apply a colormap.

tallImage = [image1; image2; image3; image4];
% Then apply the jet colormap
colormap(jet(256));
colorbar;

Let us know of further questions.

[Ryan]

Wonderful! Thank you very much for your help! It works out great!

This is the product which I'm getting as an output,and it looks terrific. Thank you very much for your help!

However, I have a second question which I hope you could help me solve too. Of these four circles I have, I was wondering if it was possible to essentially subtract the top circle's intensity to each of the other three circles in this? Essentially using it as a baseline to tare the other ones' intensities. Perhaps I could take the first circle as an ROI, and find the mean image intensity, and subtract that from each of the corresponding other circles' values?

[Image Analyst]

Yes, you can. first of course you have to match up the alignment and size (scaling). The circles have to overlap of else the subtraction is meaningless. If you just want the mean of the whole circles however, then you don't need to align and scale. But if you want a pixel by pixel subtraction or division, then you do.

Then you need to see if subtraction is the right thing to do. So you need to know what the images mean. Subtraction is the right thing to do in some situations such as fluorescence, radiography, and thermography, but not the right thing to do in other situations tracking, shading/vignetting, most visible images, etc.