ImageMagick command to convert and save with same name

Another way:

convert *.jpg -resize 80% -set filename:f '%t' ../'%[filename:f].jpg'

Will place converted files in the folder above.

The option -set filename:f '%t' sets the property filename:f to the current filename without the extension. Properties beginning with filename: are a special case that can be referenced in the output filename. Here we set it to ../'%[filename:f].jpg, which ends up being the image filename with the extension replaced with .jpg in the parent directory.

Documentation references:

• -set documentation, which mentions the filename: special case
• %t and other Format and Print Image Properties

A simple solution would be copy, followed by mogrify - another imagemagick tool - this will keep the same names, it takes all the same args as convert.

cp *.jpg thumb/cd thumbmogrify -resize 120X120 *.JPG

Alternatively you could do a bit of shell scripting, using find -exec or xargs

# using -execfind . -iname "*.JPG" -maxdepth 1 -exec convert -resize 120x120 {} thumbs/{} \;# using xargsfind . -iname "*.JPG" -maxdepth 1 | xargs -i{} convert -resize 120x120 {} thumbs/{}

Another easy way that doesn't involve a lot of typing is GNU Parallel:

parallel convert {} -resize 120X120 thumb/{} ::: *.jpg

convert is called for each of the files given after :::, and {} is replaced with the file name for each invokation. This will also process the files in parallel, so it's likely a lot faster than the other solutions here.

It also works if you want to convert the file type:

parallel convert {} {.}.png ::: *.jpg

{.} is replaced with the filename without extension, allowing you to change it easily.