Perl/Tk: Show Image from a String

[Michael]

I am trying to generate images on the fly and want to display them in
Perl/Tk without writing them to the disk. I tried to use the -data
option with JPEG, GIF, and PNG, but I always get the following error
message:

couldn't recognize image data at K:/Perl/site/lib/Tk/Image.pm line 21.

I tried the same code with a XBM file, and it worked. For the same
data, if I use -file option and load the image from a file, then it
will work too.

I am really lost, and please help.

Thank you very much.

Mike