How to choose a ROI in an image and mask the other data in a colored image?

I have images in differet time steps (sample is attached) , I transfered them into M by N by T matrix. Now, I would like to Only have ROI (yellowish color whith all the information in this region) for all sequences. Then I need to have pixel data of a constant distance from border line i.e. to have data of radious in x direction.

Answer 1

[Prahlad Gowtham Katte]

Hello

As per my understanding of your query you wish to mask the region other than the yellow-colored part of the image. You can convert the color image to binary and the white pixels represent the yellow-colored part acting as a mask. When you multiply the binary image with colored one. You get only the yellow-colored part and rest will be black. The following code will help to visualize the above.

clear all;
img=imread('SamplePicIR.png');
i=rgb2gray(img); %rgb to gray conversion
imshow(i);
bin=imbinarize(i);%gray to binary conversion
imshow(bin);
bin2(:,:,1)=bin;
bin2(:,:,2)=bin;
bin2(:,:,3)=bin;
z=immultiply(img,bin2);%Applying bin2 as a mask
imshow(z);

For more information, please refer to the following links:

• Multiply two images or multiply image by constant - MATLAB immultiply (mathworks.com)
• Binarize 2-D grayscale image or 3-D volume by thresholding - MATLAB imbinarize (mathworks.com)

Hope it helps!