trouble using axes in imcrop

I am trying to register one image with another. I am able to apply the transforms (translation, rotation and translation) to the one image which gets it to where I want it to go. However, due to these transforms the resulting image is larger than my other image. I am able to overlay them using imshow, but I would now like to crop the larger (transformed) image to be the same size as the base image (basically where the two images overlap). I do not understand how the axes work with imcrop. Below is how I plot it, followed by the failed attempt at cropping.

figure; imshow(registered,'Xdata', xdat, 'Ydata', ydat)

hold on

h = imshow(base,gray(256));

set(h,'AlphaData',0.3)

hold off

[basey, basex] = size(base)

rect = [1 1 basex basey];

[xdat ydat final rect]=imcrop(registered);

I have tried a bunch of variations of the above for imcrop but no luck. The xdat and ydat run from negative numbers while my base image starts at the origin. I hope it is clear what I am trying to do here. Thanks in advance.

Answer 1

[Image Analyst]

Did you see the demos for imregister()? I think that does what you want.

[Garth]

Thanks for the fast response. For some reason I do not have imregister or imshowpair in my version of Matlab, which is the reason I was doing this the manual way. I thought I understood the axes in imcrop but apparently I don't, so any explanation would be appreciated. Thanks.