volume fraction for 2-d image

How can I find the volume fraction difference between the two images? And is there a way to simulate the dry image looks like the wet one using matlab?

[Image Analyst]

It says wet1.jpg can't be displayed because of errors. What is your definition of volume fraction between two images? Can we assume the 2D area fraction is a measure of the volume fraction?

[Tin Man To]

Here is the new wet1.jpg. Yes, I think we can assume it as area fraction:)

Answer 1

[Image Analyst]

Just threshold

binaryImage = grayImage > someThreshold;
areaFraction = sum(binaryImage(:)) / numel(binaryImage);

Do it for each image. You might want to mask it by the circle. Let me know if you need to know how to mask.

[Tin Man To]

thanks a lot! and how about the second question? Is there a way to simulate the dry image looks like the wet one using matlab?such as dilate and erode?

[Image Analyst]

You could try imerode() on the gray scale image.

[Tin Man To]

can you show me how to mask the circle as well?

[SojM]

How would you calculate volume fraction for stack of 2D binary images? I want to divide 3D volume in small subvolumes and obtain volume fraction in each subsolume.

[Image Analyst]

volumeFraction = nnz(volumeArray) / numel(volumeArray)

volumeArray can be a sub-volume of your larger array if you want.