Legacy ImageMagick Discussions Archive

Been using ImageMagick for some time. A steep learning curve but rewarding I suppose. My computer isn't very powerful, so I cut my images before I process them. I am wondering if there is a simple way to rejoin tiles that overlap. E.g., to undo: I end up having to crop the edges before using montage to reconstitute the image, which isn't very straightforward. It would also be nice if I could blend or even interpolate the overlapping pixels, but that would be asking for too much.

~afre

If you crop without the +repage so the virtual canvas geometry is kept, then you can just flatten or possibly mosaic all the tiles to get back your image.

convert lena.png -crop 2x2+0+2@ lena_%d.png
convert lena_0.png lena_1.png lena_2.png lena_3.png -background black -flatten lena_recovered.png

I will give it a try. Thanks.

If all your files are in one folder and no others that are named as lena_xxx.png, then you can do

convert lena_*.png -background black -flatten lena_recovered.png

Note, this does not work with jpg, since jpg does not keep any virtual canvas information.

BTW, I am not using IM to process the tiles, so the virtual canvas isn't preserved. I am not successful in reapplying this info though.

I am afraid you are out of luck if the virtual canvas data is missing, unless you know exactly how to put them back together using -page xxx image1 -page ... image2 -flatten.

see
http://www.imagemagick.org/Usage/layers/#flatten

In identify -verbose yourimage, what do you see from Page Geometry. If the value always has +0+0, then you have no virtual canvas data preserved.

-page xxx image1 -page ... image2 -flatten

Thanks for the tip. I got it working by redirecting the geometry.

~afre