Icy - Icy is an open community platform for bioimage informatics
digiKam - Professional Photo Management with the Power of Open Source
ImageJ - and Other Health Care
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
JMicroVision - Image analysis toolbox: measuring and quantifying components of high-definition images
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.