Not able to store graphics on Zebra GK420t - JAVA - Windows 8.1

Hello everyone

I'm trying to store an image on a Zebra GK420t printer before printing. This image must be converted pcx black and white before being sent through the commands of the documentation. With the command "GI", the printer prints a ticket if the image has been saved or not.

The "GM" command allows me to save the image, I tried to send a file containing the path of the image, directly send the image path in string but nothing happened.
The "GK" command just above deletes an image stored in the machine that has been registered before with the same name as the one that I want to store now.


I do not understand why my order does not pass on the machine. I join you the doc and my code in hopes that someone could help me.


Do not pay too much attention to the comments, I keep them for different tests. My code really starts at ligne 95.

Thank you in advance