westfw:
Take your time.
I can't. If I delay doing it my attention will drift to something else and I'll never get back to it.
Consider how long any change would take to boil down to arduino production code, anyway.
No doubt!
(and it's not actually interesting on a 1284, since that has plenty of code space...)
If you have time, please make a pair for the m328 processor. I would like to run the same test on an Uno.
Results are in the first few rows...
The differences...
Small image: 0.00%
Medium image: -0.02%
Large image: -0.19%
...are essentially irrelevant. For the large image the "improvement" is 0.07 seconds.
If there is anything you would like me to change (e.g. the avrdude version) just let me know.