Dithering support

[forthrin]

Could you add support for dithering?

(To avoid flat, unsightly areas that appear in some images after colour reduction.)

Since you're using ImageMagick this should be simple.

PS! Thanks for a nice and simple utility.

[tzvetkoff]

Sure thing, it's relatively easy to implement.
Do you have a particular image that we can use for a test, or should I try finding one of my own?

P.S. Sorry for the late response - I didn't have much time to look at anything these days. :-(

[forthrin]

Should be easy to see this for most images when using the -p option.

[tzvetkoff]

Does pipe work for you?
I see there are quite many dithering options so I guess it's a bit impractical to implement all of them.

convert -dither FloydSteinberg christmas-pig.png png:- | ./src/im2a -p -

[forthrin]

No, because if you scale an already-dithered image (to terminal width), it becomes an ugly mess.

Also, dithering must be done in conjunction with the colour reduction (down to the ANSI palette).

Just pick a single dithering method. I think "pattern" is the best one for pixel graphics like this.

[forthrin]

When will you have a test version of this ready?