convert images to vectors

image_trace.sh

# png/jpg --(mogrify/magick)--> ppm --(mkbitmap)--> pbm --(potrace)--> svg

# mkbitmap parameters: 
# -f n == Apply a highpass filter to the image.The parameter n is a radius (in pixels) which corresponds approximately to the size of details which should be preserved.
# -s n == Scale the image by an integer factor n>0.
# -3 == Use cubic interpolation when scaling to a higher resolution.
# -t n == Set the threshold grey value for bilevel conversion.

'''shell
mogrify -format ppm *.jpg
mkbitmap -f 5 -s 2 -3 -t 0.45 *.ppm
potrace -b svg *.pbm
'''