Cylindrical projection from image normal coordinates

6 views (last 30 days)
Preetham Manjunatha
Preetham Manjunatha on 1 Aug 2021
I am trying to project normal image coordinates to cylindrical projection using the MATLAB's
function. But the output image is terrible.
fileName = 'peppers.png';
image = imread(fileName);
f = 200;
[h, w, bypixs] = size(image);
K = [f,0,w/2; 0,f,h/2; 0,0,1];
x = 1:w;
y = 1:h;
[X,Y] = meshgrid(x,y);
X = X';
Y = Y';
XYZ = [X(:) Y(:) ones(h*w,1)];
XYZnew = (K \ XYZ')';
A = [sin(XYZnew(:,1)), XYZnew(:,2), cos(XYZnew(:,1))];
B = (K * A')';
% back from homog coords
B = B(:,1:2) ./ B(:,3);
% Make sure warp coords only within image bounds
B((B(:,1) < 0) | (B(:,1) >= w) | (B(:,2) < 0) | (B(:,2) >= h),:) = -1;
B = pagetranspose(reshape(B, w, h, 2));
% Image warp
Icy = imwarp(image, B, 'FillValues', [0 0 0]);
% Display warped image
subplot(1,2,1); imshow(image)
subplot(1,2,2); imshow(Icy)
Below is the output image:
Any inputs to solve this issue is much appreciated!
Preetham Manjunatha
Preetham Manjunatha on 1 Aug 2021
It should look like this:
Above image has transparent background, in my case it is black. Cylindrical projection is a mapping from the Cartesion (or any) to Cylindrical coordinates. Here I am trying to warp the given normal/regular image to Cylindrical coordinates to get better panaroma stitching.

Sign in to comment.

Answers (0)

Community Treasure Hunt

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

Start Hunting!

Translated by