I am creating figures for a scientific paper. The journal I am submitting to seems confident "all figures can easily be reduced to less than 50kB each (gzipped) without significant loss of quality". One figure I am starting with in photoshop PDF format is ~30MB. I cannot comprehend how I am possibly going to reduce this down to ~50KB without significant loss, but perhaps there is a way?
My image has text, symbols, colour charts and sharp lines that represent functions. I include a screenshot of the image below, and a dropbox link to the actual file just in case that is helpful: https://www.dropbox.com/s/m3p6j6fmccnfvgw/figure2.pdf?dl=0
Any help greatly appreciated :)