Mean filter -> Fast and easy to use. This will likely be the only filter
that gets alot of action on the M4.
Median filter -> Works really well, but, slow. On grayscale at 160x120
you can get also 10 FPS with it for a 3x3 kernel. That said, it's still
slow. Also, the code only works for 3x3 and 5x5 kernels.
About the previous histogram filter... technically, that filter should be
better. However, it suffers from a startup cost. The operation of finding
the median point in the histogram costs too much to compute. This is
what causes it to be slow. On very large kernels it will be faster than
the sorting median alrogithm I put up... but, large kernels will be too
slow for anyone to use anyway. The paper Ibrahim linked to about it
showed it being used for like 7x7 kernels and up... so, I think the
researcher who thought of the idea was really thinking about the
algorithm for large kernels.
Mode filter -> Works great on grayscale. Not so much on color. I think it
needs to be run on the LAB color space instead of the RGB color space. I
say this because it causes pretty strong artifacts around edges. When we
get more flash we'll be able to have a reverse lookup table for LAB to
make the mode filter better. Until then...
Moved feature detection scripts into their own folders and added explict
frame_skip value per Ibrahim's request.
Finished working on snapshot and video recording scripts for next
release.
... From CMUcam4 work I learned that people will just want examples that
do "X" thing. So, in general, our examples should include a simple
script showing off a feature and then a more complex script that does "X"
where "X" is some app that a person would want. For example, we'll get
reuqests for face tracking with servos, and movement detection with
servos. So, instead of answering this question a million times with an
example script we'll just have examples for all kinds of things people
will want.
Gotta automate dealing with help support at the end of the day...
Tried to emulate Arduino's 11 folders... I'd perfer to have all the
shield scripts in one folder... but, that might not make sense. I don't
really want one script per folder however. So, I might merge some more
stuff in the future. I have a grand idea here that will become evident as
I work though the examples.
Anyway, the current structure is not final. It will be in flux for a
little while.
As for Git History, folder history is the best we're going to get. Git
and GitHub don't seem to deal with moves too well.
So I'm just adding a function to do it cleanly and efficently. Call
skip_frames() after changing any camera settings to let it settle.
10 frames by default works fine. Tested it.