crop with 0 offset changes image's dimensions

[CatBurgers]

On 6.9.2-8 Q16 x64 for windows:
Image a.png is 1472x208, to which I apply a crop using:

Code: Select all

convert.exe a.png -crop 1472x208+0+0 b.png

Which shouldn't really do anything, but b.png is actually changed (it becomes 1398x208). If I remove the offset options with:

Code: Select all

convert.exe a.png -crop 1472x208 c.png

Then the dimensions are not changed.

You can view the output here: (from top to bottom: a.png, b.png and c.png)
http://imgur.com/a/VdVb1

[glennrp]

The input image contains an oFFs chunk, which is probably interfering with the result you expected.