B&W (Grayscale) Conversion in GIMP
patdavid | Software Techniques | Published Feb 7, 2013
A (relatively) comprehensive look at various methods to convert an image to B&W grayscale in GIMP.
I've walked through just about every possible method of generating a B&W grayscale image in GIMP, and present them with some notes and thoughts on each process.
The topic is a rather large one, so I broke them up into 5 different sections to make it a little easier to digest all of the information. There's a good chance that something in the overall tutorial might prove helpful to developing your own B&W workflow!
Using the straight Desaturate command, and how each of the modes calculates the final pixel values. This mainly looks at how
will affect your final pixel values and results.
Part 4 investigates some functionality exclusive to GIMP, and how to use layers to adjust the grayscale image right on the canvas.
The exclusive parts deal with using GEGL c2g (color 2 gray) to automatically adjust local contrast during value determination based on the brightness of the surrounding pixels.
This part also touches on using the Pseudogrey algorithm to produce an image with up to 1786 different shades (far more than the 256 shades of gray available in a "true" grey image).
The final part of this tutorial looks at using everything that was covered in the previous portions, and how to blend the different results together using simple layer masks. This gives a great amount of control over the various tones in your image to highlight or depress various features.