how to superimpose a surface plot on a different size gray scale image

2 views (last 30 days)
I have a grayscale image which has a size of 2448*2048.
I have a surface plot on a mesh grid of (1:110, 1:92)
Their data numbers are totally different. How can I make the grayscale image as the background and make the surface fit right onto it and transparent so that I can see the background image through the surface plot at the same I can still draw ROI on the surface plot with the roipoly function?

Accepted Answer

Walter Roberson
Walter Roberson on 14 Feb 2018
Look at the XData and YData parameters of image(): you can specify the coordinates of the centers of the bottom left and upper right pixels. Getting them to line up exactly with the boundaries of (for example) 1:110 is a bit of a nuisance because you have to account for the 1/2 pixel, which will be 1/2448/2 or 1/2048/2 of the image, but you can do it (but it's usually easier to just let half a pixel hang outside the surf plot.)
When you create the surf() plot, you will probably want to use 'edgecolor', 'none'. Make it transparent by passing in 'AlphaData', such as .8 .
  3 Comments
Walter Roberson
Walter Roberson on 14 Feb 2018
All points in the image() are considered to have Z of 0, so Z below 0 on the surface plot would be "behind" the image.
You should consider using
surf(X, Y, ones(size(Z)), Z)
so that your Z data gets interpreted as "color" and so MATLAB thinks your surface is at 1 (and thus "above" your image.)

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!