How to count each colour pixel of an image?

I am trying to quantify the value of of each matter of the brain using matlab. I have segmented the image and result as shown below.

[Akira Agata]

Is it a result of k-means clustering? If so, you can count each color pixel easily by using the output variable of kmeans function.

[muhaimin mahfudz]

yes it is. I see, in conclusion i can just obtain the values from there as it is the value of each segmented color?

Answer 1

[Image Analyst]

Take the histogram of your segmented/classified image

counts = imhist(classifiedImage);

Each class will have a certain value, like gray matter is 1, background is 0, white material is 2, etc. imhist() simply counts the pixels in each class.

[muhaimin mahfudz]

However I wish to know the amount of pixel for each colour. I tried one of the codes given by you (https://www.mathworks.com/matlabcentral/answers/364315-how-can-i-count-pixel-of-particular-color-in-image) however it does not produce any result.

[Image Analyst]

imhist() will do it. You pass in the classified image, not an RGB image, but the image you got from kmeans. See attached demo.

[Image Analyst]

Do you still not understand? If so, give me the script you used to create that image along with the original image.