ImageJ - and Other Health Care
GIMP - GIMP is a multiplatform photo manipulation tool.
Fiji - Fiji: A batteries-included distribution of ImageJ.
Image Pro - Used by researchers worldwide, Image-Pro Plus image processing software makes it easy to acquire images, count, measure and classify objects, and automate work.
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Icy - Icy is an open community platform for bioimage informatics