#563 tile:<image> appears to blow image up by 100% before applying tiling

[Patrick Putnam]

Steps to reproduce:

Using a 100x100 image box.jpg, enter the following:

gm convert -size 200x200 tile:box.jpg box2.jpg
gm convert -size 400x400 tile:box.jpg box3.jpg

Expected Behavior:

box2.jpg is a 2x2 tile of the original 100x100 box.jpg image
box3.jpg is a 4x4 tile of the original 100x100 box.jpg image

Actual Behavior:

box2.jpg is a 1x1 tile of a 200x200 copy of box.jpg
box3.jpg is a 2x2 tile of a 200x200 copy of box.jpg

One can fairly easily work around this by simply creating a canvas that is 2x as large as necessary and then resizing it back down, but obviously this shouldn't be necessary, and can be a hassle for more complex command strings.

[Bob Friesenhahn]

This is a very interesting finding. The problem is specific to the
JPEG file format (and the few other formats responding to -size) since
-size influences the image size that libjpeg returns. If you use an
input format which does not respond to -size, then the issue will not
occur.

Bob

[Bob Friesenhahn]

This problem is fixed by Mercurial changeset 15657:f298a4c346e5. Thank you for the bug report.

[Patrick Putnam]

Cheers! Thanks for the fast response.