Convert RAW to JPG
Install prereq's
sudo apt install imagemagick dcraw
Convert a single image from canon CR2 raw format to JPG:
dcraw -c -a -h ./IMG_123456.CR2 | ppmtojpeg > IMG_123456.jpg
Convert many canon CR2 raw format photos to JPG:
for i in *.CR2; do
dcraw -c -a -h $i | ppmtojpeg > $i.jpg;
echo $i
done