Raster laser software that will ignore white space?

Is there such a software that will essentially fast forward past blank space in a raster drawing. Currently what I am lasing right now has a couple hours of nothing because it has a lot of white space around the outsides. I thought I came across something that would basically ignore the nothing code to the first line with some variation of the laser intensity.

I think the image2gocde thread has a GitHub link on the first post. That version has a bunch of experimental features. Bryan added the whitespace skipping but I think it only works with horizontal engraving. I never really played with it much, give it a try.