I have put together all of the imaging software that I know of that can be useful to PTE users, above all freeware or under GNU license (Open Source). I chose to divide the software into three categories, even if almost everything is trying to become "all-in-one" software (a choice I don't agree with) :

Image Editors (complete editing of pictures, rather "heavy" and slow to start);

Image Viewers (little, very fast, with minimal editing features)

Image Enhancers (more or less little software for very specialized operations, e.g. to increase image sharpness), which complete features not present or not statisfactory in larger image editors.

Image Editors

Commercial software (sorry, I can't ignore it...)

Adobe Photoshop is the undisputed leader of image editors, professional-oriented and extremely powerful, but also very expensive and with a hard learning curve. It's almost impossible to list all its features, but we can say it's able to do all you can want, thanks also to hundreds of plug-ins available on the Net.

Adobe Photoshop Elements is the little brother of Photoshop, more user-friendly but also much cheaper. It's a software amateur-oriented, with several automatic features.


Shareware

Jasc Paintshop Pro (now acquired by Corel) is another powerful and excellent software, less "professional" than Photoshop but very complete even for advanced users, and much cheaper (near 150$, 99$ the limited edition, named "Paintshop Studio"). It can use the same plug-ins as Photoshop.

PixBuilder Studio, the last born one, has been created by WnSoft, the same software house of PicturesToExe. Like this, it's very small and agile (1,2 MB!), but very powerful. The interface is almost the same as Photoshop, and its functions are very complete for amateur photographers and also most professionals. The price is 34$, less than 29 euros. English and French versions available.

Photofiltre Studio, the new outsider: it has the same interface of Photofiltre (see below), but it supports layers and can create animated Gif's. Its price is 25 euros. Only French and English languages available (for now).

Freeware

Gimp, originally developed for Linux users, is a very powerful image editor, not diffused yet among Windows users. This due to its complexity (not far from Photoshop). Lots of plug-in. All languages.

Pixia, an outstanding little Japanese piece of software is very interesting and effective, a complete digital imaging solution. Many languages available.

Photofiltre is a very interesting and versatile French software (available in all common languages). Let's say it is a "little Photoshop", without all those features - such layers, color spaces etc. - which make Photoshop a professional software but are useless for the common user, and with a lot of editing tools and more than 100 filters (some very original and not available in Photoshop). Several plug-ins. French, English, Czech, Dutch.

Image viewers

Freeware

Irfanview is a well known and commonly used picture viewer, very fast and suitable. It features also some simple but important editing abilities such as color management, batch resizing and format conversion. With its plug-in pack it can also play sound (mp3, wma, wav, ...) and movie (avi, mov, swf, ...) files. All languages.

XnView is French software with features similar to Irfanview, and can open (and convert) nearly all existant graphic format (more than 400, included many proprietary formats). Languages: English, French, German.

Image Enhancers

Freeware

Digital Camera Enhancer is a little (523 KB) software very useful in increasing the sharpness of pictures and in removing the graininess (the "electronic noise") of digital images. There is also a shareware version, with more extended features.

Neat Image is shareware, but the demo version can be freely used for non-commercial purposes. I quote from its presentation: "Neat Image is a digital filter designed to reduce visible noise and grain in digital photographic images [...] (it) not only reduces the high ISO noise associated with image sensors (CMOS, CCD) in digital cameras and scanners, it can also reduce the film grain visible in scanned slides and negatives, JPEG artifacts of overcompressed images, and color banding".

SharpControl is a sophisticated, very effective sharpening tool, even if it is rather slow. Its creator ("Vtie") posted a link to it on Digital Photo Review (dprevue.com) forum, but the download page can no more be found. So I have resolved to publish myself this little program (340 KB), in hopes that its author will turn up. You can find a good tutorial here.

Image Analyzer. I didn't know where to place this unusual software, which is rather difficult to classify. In the hands of an experienced user it's an extremely powerful image editor and enhancer, highly customizable, but it's very difficult to handle, and sure not advisable for occasional users. Anyhow, it's worth an attentive test. Languages: English, Danish, Dutch, German, Portuguese.