comparing hog dims...
argh, i think piotr's dims don't quite match because... Piotr does: width = imgWidth / cellSize; height = imgHeight / cellSize;  and, Ross's VOC5 code is a bit more complex ... round(imgHeight / cellSize), and later the rounded value has 2 subtracted from it
doing round(imgWidth / cellSize), but it doesn't seem to help. I wonder if I need to propogate this elsewhere in Piotr's code.
looks like the dims match now. Crux was: hb = round((float)h / (float)binSize); wb = round((float)w / (float)binSize);  -- for Piotr's code.
interesting: hog % match between Piotr and Ross varies a lot. I think this is dependant on whether the offsets match or not. The ones that seem to match (which used to have mismatched dims) match to within 2-3%. But, the 'previously mismatched dims' ones can be different by up to 35%. I suspect that this is all correct, and the only (problem?) is that the dims don't quite align. Probably ok. Might spend a bit more time trying to trace down the difference, though.
happy with diff vs Piotr's code, for now. If I end up wanting to use Piotr's code in my system, I might dig deeper into the diffs.
experimenting with dims in Piotr's code. When visualizing, stuff looks skewed and kinda unrecognizable in Piotr's results, while the VOC5 results make more sense visually. (for the case where Piotr and VOC5 dims don't match). I think the key may be to ensure that strides are correct in Piotr's code after my dims modifications.
more playing with dims
more dims experiments ... same match / mismatch situation.
god matlab parfor is dumb. it can't even have a variable that has different indicies depending on thread...
back to non parfor
temporarily remove csvdiff