Help with using SURF to analyze an image?

26 views (last 30 days)
Taylor Gates
Taylor Gates on 13 Jul 2018
Answered: Image Analyst on 14 Jul 2018
So I am trying to analyze and image using "surf" to make a 3D plot whose z value is the gray scale, where darker image will have lower z (Black is 0, White is 255). How would I use surf to analyze an image like that?

Accepted Answer

Rik
Rik on 13 Jul 2018
What your goal is, is not really clear to me, but you can use the code below to view an image as a surf. I used an example image packaged with the IPT, so if you don't have that toolbox, you'll have to use your actual image.
figure(1),clf(1)
peppers = double(imread('peppers.png'));
IM=peppers(:,:,1)*.3+peppers(:,:,1)*.6+peppers(:,:,1)*.1;
[X,Y]= meshgrid(1:size(IM,2),size(IM,1):-1:1);
surf(X,Y,IM,'EdgeColor','none')
colormap('gray')
view(10,90)
  6 Comments
Rik
Rik on 14 Jul 2018
Just to clarify: you can still 3D rotate this. The line with view just sets the camera to a point where you can easily recognize the image.

Sign in to comment.

More Answers (2)

Image Analyst
Image Analyst on 14 Jul 2018

Image Analyst
Image Analyst on 13 Jul 2018
You wouldn't. The surf() function in base MATLAB just for visualization of smooth images, as opposed to SURF from the Computer Vision System Toolbox. The surf() function is not very good for visualizing rough images, and no good at all for analysis. See my Image Segmentation Tutorial in my File Exchange for an intro to image analysis.

Tags

Community Treasure Hunt

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

Start Hunting!