Have a faster way of comparing

[RedyAu]

I'm very happy with this package, apart from its speed. It takes a while to get the differences.
I'm seeing percentages down to the billionth digit returned, this is totally unnecessary for me, it would be enough if it returned for example tenths only and was faster.
I have no idea if this would be even achievable without rewriting the whole thing, but it sure would be nice.
Also, I have a sneaky suspicion, that even if I request the percentage, the algorithm first generates the diff image, and gets the percentage from that. If this is the case, I don't know how, but it would be nice to get rid of the image generation too, when unnecessary.

[limonadev]

Hi! Could you share the images you are trying to compare? (And the times you are getting with them). This way I can try to optimize the code to improve the processing time based on your own benchmarks :)