Area between two curves without equation

I want to calculate the area between two curves (green area). I do not have equations of curves. Two curves (zigzag and red line) are two separate images of same size (can be binary). I want to put them on eachother and calculate the area between them. Thanks in advance for your helps.

Answer 1

[Walter Roberson]

imbinarize(), or() them together, fill holes, regionprops the area