Nice info this -data parameter! I'll have a look at it. About Imagemagick, I have no experience with it, but by reading what you've written, it seems to be very similar to Imager. Anyway, it would be very nice to be able to write data in a binary format on Tk::Photo, instead of converting it to string format and deconverting again. Thanks for your help!
I'm not sure if you'd seen this particular thread or not. It demonstrates that attribute being used in several of the examples. Perhaps it will help...