GreyEdit is an editor for greyscale images.

Features :

    Can read (greyscale) Clear format files.
    Can write (greyscale) Clear and Sprite format files.
    Can perform a variety of processing functions : crop, filter (e.g. blur, sharpen, noise), range expansion, equalization, invert, simple pixel editing (e.g. to remove noise pixels by hand).
    Serves as a frontend for, and can grab video images via, the Zeridajh video digitiser podule, if fitted (only a small number of these podules were sold, but the hardware design was eventually published in several international issues of Elektor in 1991). 

Note that GreyEdit is basically only useful if you have a Zeridajh video digitiser. If you don't, Translator (or even !Paint in some cases) will probably be of much more use.