Export plates to separate jpg files

Can someone please help me to export the plates of a selected shaperange to grayscale jpg files.

A partial solution is to export a pdf with each separation plate to a page but I dont know how to code that.

Is important that the file/page to be filled completely with the graphics  and do not have white zones as they appear when listed on center of page on conventional formats (A4 or letter for example).

Thank you in advance!