Convert color image to grey scale

[RealGomer]

I have a color image that I want to convert to grey scale / black & white. I can't find a tool or filter to do this. Did I miss something?

[neurolurker]

For a start you might try  Colors: Desaturate.  And then select Desaturate from the flyout list.  This gives you five modes of grayscale and about 20 ways to blend the grayscale and color image.  The differences between some of the modes may appear subtle but may become more important as you work with other GIMP features.

[rich2005]

There is also Image -> Mode -> Greyscale

[Kevin]

And if you want to get some more control over the conversion, try Pat's article: https://pixls.us/articles/digital-b-w-conversion-gimp/

[RealGomer]

Yup. I missed something. Now to get one image "perfectly" superimposed over another. Ah, the joys of computer. So much more can be done than back in 1980. Usually with so much fatter software.

[Ofnuts]

(07-24-2020, 12:21 AM)RealGomer Wrote: Yup. I missed something. Now to get one image "perfectly" superimposed over another. Ah, the joys of computer. So much more can be done than back in 1980. Usually with so much fatter software.

It depends....

If the images are consecutive photos of the same scenes taken hand-held, the non-obvious difference it that the camera axis likely rotated a bit between the two (in addition to the camera position no being exactly, the same). There is no simple transformation in Gimp to compensate for this, panorama software such as Hugin do have this kind of functionality built-in (image stacking).

If the image are different anyway (the face of two different people), you can make the top temporarily partially transparent, and use the Unified transform tool to scale/rotate the top image to match the other one.