Irfanview allows you to sharpen images while viewing them, while PhotoScape and Gimp allow you to choose how much you want to sharpen each image, as well as select the radius and amount of ...

If you're using GIMP, use "Cubic". Change the color mode to "Lab Color" and use Photoshop's "Smart Sharpen" feature, or a slightly more manual sharpening method in the GIMP.

GIMP is a free open-source graphic software that is good for photo editing, photo manipulation, tracing, and much more. Learning how to trace images and objects in GIMP is a way to get your hand ...