An idea how to lossless optimise jpg, png recursivelly on linux?

[postcd]

Hello,

please any idea how to optimise (lossless) many images (jpg, png, gif) recursivelly on linux?

Trimage

I found nice looking tool: http://trimage.org/

its options:

-f FILENAME, --file=FILENAME
compresses image and exit
-d DIRECTORY, --directory=DIRECTORY
compresses images in directory and exit

they say its a lossless optimizer "All image files are losslessly compressed on the highest available compression levels."

so here is an idea on command?

find . -type f -name "*.jpg" -o -name "*.png" -exec trimage -f {} \;

JpegOptim

next tool jpegoptim (man page): http://www.cyberciti.biz/faq/linux-jpegoptim-jpeg-jfif-image-optimize-compress-tool/
someone provided this command:

find . -type f -name "*.jpg" -exec jpegoptim {} \;

(in man page is mentioned lossless is by default)

PngOut

third tool is pngout (PNG lossless only):

find . -name "*.png" -exec /usr/bin/pngout {} \;

is it safe to do these commands? or do you advice anything else please?