This app 'keystone corrects' a given image. Basically, it straightens merging lines to correct perspective as expected in photos of tall buildings, snapshots of display boards shot at an angle, etc. A discussion of the algorithm behind this app is given here: https://jkmsmkj.wordpress.com/2013/07/27/projective-transformations .
[For "draggable quadrilateral corners", see this post on Mike's blog: http://blogs.mathworks.com/graphics/2015/12/31/interactive-graph-layout/ ]
Any feature suggestions or comments are welcome. Thanks for trying the app (if you did, that is) and enjoy (the life, in general)!
Thanks Nikolay. I don't use the image processing toolbox so can't help you with the built-in functions.
I can share my basic code if you send me an email.
Very nice app, but I need to correct for distortion series of images, so I will have to write my own code for this purpose. Could you tell me, what function do you use to warp the image after the parameters of transformation are determined? I tried to calibrate the camera, then using projective2d to determine transformation, invert and imwarp to correct the distortion, but this seems the wrong way, since imwarp produces downsampled image.
Chun-Jen Hsueh: Could you please let me know the error you get when trying to load an image? Thanks.
This app doesn't work. I can not even read an image.
Revamped GUI (Draggable quadrilateral corners to select the region to be corrected, Border extent selector, Previews of selected & corrected regions, etc.); Updated algorithm to take care of non-convex regions; Custom crop option.
Cropping algorithm updated; More options for saving an image; Minor GUI & bug fixes.
Inspired by: GUI Layout Toolbox
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