Perform a manual SaveAs from Solidworks and choose "Options" after choosing the JPEG filetype. You can set you options here to perform a Print Capture instead of a screen capture that should help. In the task code you should be able to set the options using API but I do not know for sure. If you set these options manually then the automated task will use them until they are changed again. You can also leave it at screen capture and make sure your task performs a "Fit to Screen" first.
SolidWorks has the possibility to set the format, ok.
I need a TASK in EPDM for that, now i'm sure it use the last format saved in SolidWorks.
I think EPDM can't does this operation in complete indipendence.