The old code did not actually implement the errode anhd dilate kernels
correctly. However, it migh have been a little faster because it avoided
the boundary problem.
In the future we can optimize all the kernel code to have different loops
for doing the edges of image versus the center. But, for now, this is
good enough. QVGA color tracking with kernels will be slow, but, the
speed can be improved with QQVGA resolution. Using a 3x3 kernel is
plenty fast. Larger ones are slower.
I also added the ability for you to set the threshold for erode and
dialte. This lets you make the kenrel a little bit smarter so that it
won't errode or dilate a pixel unless the threshold is met. Meaning,
you'll be able to use erode to erode an image down to 1 pixel wide
lines.
It now figures out the file type from the file extension. If no file
extension is given it just saves the file as BMP if its not a JPEG image
or JPEG if it's a JPEG image. If you specify an extension and the file is
not of that type then it will give you an error.
The new test_save.py should run until you reach the JPEG image part
where it quits due to lack of JPEG support natively on OV7725 boards.
Maybe JPEG mode should be supoorted by just compressing pictures?
All the drawing functions have been updated to handle automatic clipping
when drawing offscren and work with both grayscale and RGB565.
Additionally, all functions now accept color arguments.
I've also updated the example scripts with the new functions and tested
them out to make sure they work.
Additionally, I wrote a test suite for the drawing functions to make
sure they work.