Enable output of image sizing

[joshuaburkhow]

Currently users have the option of outputting to a PNG image but currently can only use Inches to get the size set. I want to be able to output with a pixel size not in inches. 

[KylieF]

Thank you, this is great feedback for the reporting tools!

Would you prefer this be a sort of user setting or a drop down toggle? Or would there be a third more preferred method of how you'd like to see this implemented should be we able to?