What is the best way (Free is possible) to reduce the size of an image data file??

Im looking to reduce the actual data file size (not the image size) of image files like jpg gif or bmp. What is the best way to do this preferably with free software.?

I used irfanview and reduced the dpi resolution and it cut down somewhat. then I reduced the number of colors in the file attributes and it cut down some more. Originally the filie was 100KB but i can get it to 52 KB then it doesnt seem to reduce anymore.

 

try this: http://tools.dynamicdrive.com/imageoptimizer/

 

Thanks a l ot ALAN, It worked beautifully.

 

try Radical Image Optimization Tool (a.k.a RIOT). Just google it

 

Thanks for the RIOT suggestion. It is also a very interesting program. I see they even have a Plug-in for GIMP and for IRFANVIEW. Thats great.

 

You are welcome, LifeMaster.

I do also have a paid program from Balesio, Balesio File Minimizer for Picture, but RIOT (which is free) is still better and give you more option for optimizing.

 

I use http://www.netmechanic.com/GIFBot/optimize-graphic.htm

 

Photoshop ?