Raw Therapee is an open source image processing tool which provides a huge range of ways to enhance your digital photos and other images. (As the name suggests, it's intended for use with raw files from digital cameras, but the program can also import JPEG, TIFF and PNG files.)
The vast array of high-end novices will quickly confuse the image processing novice, but if you know what you're doing then there's a great deal to explore here.
RAW image quality may be enhanced by a good range of demosaicing algorithms, for instance: AMaZE, DCB, fast, AHD, EAHD, HPHD & VNG4.
Colour handling controls cover everything from simple channel mixing and RGB curves, to white balance, HSV, vibrance and more.
Would you like to enhance details? The Detail pane contains no less than seven options: Sharpening, Edges, Microcontrast, Impulse Noise Reduction, Noise Reduction, Defringe and Contrast by detail levels. And each of these is highly configurable, so for example select Sharpening and you can choose the algorithm (Unsharp Mask or RL Deconvolution), radius, amount, threshold and more.
And you also get great exposure controls, a stack of powerful lens/ geometry correction tools, EXIF/ IPTC metadata editing, batch processing, command line control, lots of configuration options, and the list goes on.
Beginners should look elsewhere, then, but if you're familiar with this kind of high-end image processing tool then you'll get a lot out of Raw Therapee. Its interface is occasionally clunky and performance isn't always as good as the authors appear to think, but there's an enormous array of processing power on offer and it's a great way to get the very most from your digital images.
4.0.11 additions include:
- CIECAM02 hot/bad pixel fixer to prevent bright pixels from appearing
- The Defringe tool is now able to target a range of specific colors without touching others
- New keyboard shortcuts to apply rank and color labels and a new direct popup menu for color labels, all in the File Browser
- "Profile Fill Mode" button controls whether to replace missing processing profile values with default ones or not
- New demosaicing algorithms for noisy photos: ?LMMSE
- Support for TIFFfiles with alpha channels
- Support for 32-bit TIFF files (HDR)
- Support for Nikon D5200, Nikon D7100, Nikon COOLPIX A, Panasonic Lumix DMC-G5
+ Many significant speed improvements and bug fixes.