Merge blurrs #34

[joshinils]

change applying blurrs to using masks two masks, one with less blurr than the other. each mask contains a union of all detections per frame.

this way all detections which overlap (from this frame or previous frames) will look the same amount of blurred at the end. so no overlaps are blurred twice or more and thus creating visible artifacts.

closes #34

[joshinils]

sorry, this includes the commits from #30 but has nothing to do with it, so i created another branch and pull-request.

there is a slight visible border between the inner and outer blur, but that was there previously aswell. i guess any compression and youtube make that go away completely

[joshinils]

old:

with my changes and using a Gaussian blur:

[joshinils]

only problem could be, that now the strength of blurring is different since the gaussian blur works different to a box blur kernel, but in my opinion looks much better. i also had to change how the input parameter is used, since the gaussian blur needs an odd size: https://github.com/tfaehse/DashcamCleaner/blob/7450118fba1159aec17495ee38af74a7da2b9aa4/dashcamcleaner/src/blurrer.py#L44 old: https://github.com/tfaehse/DashcamCleaner/blob/ad3039aeed42b5ba53769282763e844cf8b6f360/dashcamcleaner/src/blurrer.py#L38

so the cli argument of --blur_size is doubled at the moment. but it could be changed to only accept odd values in range [1, 3, 5, ..., 97, 99]

[joshinils]

in theory it is possible to use different blurs for the first and second mask, if you wanted, so a weak box blur for the outer blur, and a nicer looking gaussian for the inner box

[joshinils]

-b	3	4	5	6	7	8	9
gauss size	7	9	11	13	15	17	19
gauss
old w/ box

of course the old version still has the off by one error regarding the detections age, so here it also uses the previous detection too, and thus blurs parts of the face multiple times.