If you are using Linux, GIMP probably came with your distribution. You can get GIMP from the GIMP website downloads page but for the none geek this can be somewhat daunting so I’ve chosen some trusted third parties to get it from. Windows users should download it from Ninite. Mac Users
Tag: free
Extracting Images Using Contrast
You can extract an image from its background by using high contrast to distinguish the background from the subject. Project File
Good-N-Free Meetup 