Processing and editing images in Lab mode

Output

In the last tab, Output , you can set how Photivo is to send the image. Most entries are self-explanatory. RGB curve corresponds to the normal value curves and interferes with the L* curve . The sRBG gamma compensation output has relatively large effects that you don't necessarily need to activate.

The selected Output color space determines how Photivo converts the image files into output files. The five versions sRBG , sRGBlinear , ProPhotoRGBlinear , AdobeRGBlinear , and WideGamutRGBlinear differentiate themselves mainly by the amount of colors they produce. Wide-gamut RGB encompasses a good three-fourths of all the Lab-defined colors, sRGB only about a third, and Adobe-RGB just about half [8]. Wide-gamut color spaces make sense only with 16-bit input and output data. Adobe-RGB is mainly used for printing because of its better green tones.

Among the Output settings Photivo provides 16-bit versions of the usual 8-bit PNG and TIFF formats, as well as PPM. Only these formats ensure maximum output quality, albeit at the expense of much higher file sizes.

Conclusion

With Photivo, you get a powerful tool for enhancing (RAW) images, but you certainly won't want to do this without some experimentation first. The program fills the gap between purely RAW converters and classic image processors. Corrections to RAW images are best made before the actual image editing, where the high processing speed proves advantageous.

The only thing missing that Photivo developers could consider integrating is the Luminance-HDR code.