How to batch convert JPEG images with jpegtran on Windows

Question

Is it possible to batch convert a folder of JPEG images using jpegtran on Windows?
I normally use the following command for one file, but I'm not sure how to apply it to an entire directory of JPEG files:

jpegtran -copy none -optimize a.jpg b.jpg

Thank you.

Answer 1

How do I operate jpegtran on a bunch of images at once?

I've not used jpegtran myself before, but based on your example command you can enter the following at a command prompt:

cd /path/to/where/images/are/stored
for %f in (*.jpg) do jpegtran -copy none -optimize %f %~nf-new.jpg

Note that this assumes you are running from cmd.exe command prompt; if you are in a batch file the %s need doubled to %%.

See the for reference for more information.

Explanation

for %f in (*.jpg) - loop through all files ending in .jpg extension using the variable %f

do jpegtran -copy none -optimize - do this action (using your example jpegtran above)

%f - variable with filename plus extension (original file)

%~nf - variable with filename without extension as per reference above (new file with -new.jpg appended)