I used the php-barcode code to create EAN barcodes.
This works well and creates png files with just black and white.
When I use "gm convert rotate ean.png -rotate 90 eanrot.png" I get a wrong result.
Just to doublecheck it is not me, I used the imagemagick "convert rotate ean.png -rotate 90 eanrot.png"
which works just fine.
So it seems to be a gm bug.
see my testimage here :
sorry, wrong link
and the result after rotating:
This is an issue with GraphicsMagick's PNG writer which was fixed in the 1.3.17 release. Versions 1.3.13 through 1.3.16 had this problem.
Sorry, I meant PNG reader rather than writer.
I did just verify that there is no problem with the current (1.3.17) release. I wanted to make sure since there have been a few more PNG fixes since the release.
What version are you using?
I used 1.3.15, the self correctet one with the dpi/cm calculation (I guess you remember).
I will update to 1.3.17. Thanks for your help!