Batch Image Conversion with sips (MacOs X)
▻http://osxdaily.com/2013/01/11/converting-image-file-formats-with-the-command-line-sips
Converting a group of images is a little trickier, and using simple wildcards like when resizing with sips doesn’t work quite the same. You’ll find that using a generic wildcard like * doesn’t rename the file as well, so we’ll use very simple shell scripting instead with the following command syntax:
for i in [filename]; do sips -s format [image type] $i --out [destination]/$i.[extension];done
Putting that to use, we’ll convert a folder of .jpeg files to png files in a new subfolder of the current directory, called “Converted”:
for i in *.jpeg; do sips -s format png $i --out Converted/$i.png;done
#sips