Hopefully someone can help me with this..... may not even really be an Imagemagick issue
I have to create several thousand QR codes at a time which I do by downloading from a site which generates them - they save as png files.
I then need to convert them to CMYK files (to keep a printer happy), so I batch convert to jpg as follows:
mogrify -format jpeg -colorspace CMYK *.png
This seems to work fine, but when I use them in Microsoft Publisher merge and export to a pdf, it seems to give up half-way through the file and puts in a square with a red x (like a placeholder) on some of them.
I expect this is an issue with Publisher as some times if I run the same file it gets more correct than others. Unfortunately I'm stuck using Publisher because I need it's 'shrink to fit' text facility. I'm also stuck with the Office 2013 version, as I'm told the Outlook server will have a problem if I try to update to 2016.
If I run the merge with jpegs then the 'red x' problem does not occur.
So my question (got there eventually!) is: how can I use mogrify in a way that won't cause MS Publisher to play up?
Is there anything I can do to make the final file more efficient? - I've tried lossless compression, but that actually increases the file size (we are only talking about a file which was 281 bytes as a png and is 2.79KB as a converted jpg).
Any ideas would be much appreciated!