Jarvis-judice-ninke dithering

Feature request...

I wanted to use jarvis-judice-ninke dither but it is not in Pillow nor seems planned.
jarvis-judice-ninke is a more enhanced variant of floyd-steinberg.

while floyd- steinberg uses:
*7
351

jarvis-judice-ninke uses:
*75
35753
13531

for the diffusion matrix. this does mean it is a little slower. however, Pillow is fast enough that the speed difference may be unnoticed for typical use cases.

--------------------------------------------------------------------
Pillow 12.1.1
Python 3.13.12 (tags/v3.13.12:1cbe481, Feb  3 2026, 18:22:25) [MSC v.1944 64 bit (AMD64)]
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Python executable is C:\Users\Owner\AppData\Local\Python\pythoncore-3.13-64\pythonw.exe
System Python files loaded from C:\Users\Owner\AppData\Local\Python\pythoncore-3.13-64
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Python Pillow modules loaded from C:\Users\Owner\AppData\Local\Python\pythoncore-3.13-64\Lib\site-packages\PIL
Binary Pillow modules loaded from C:\Users\Owner\AppData\Local\Python\pythoncore-3.13-64\Lib\site-packages\PIL
--------------------------------------------------------------------
--- PIL CORE support ok, compiled for 12.1.1
--- TKINTER support ok, loaded 8.6
--- FREETYPE2 support ok, loaded 2.14.1
--- LITTLECMS2 support ok, loaded 2.17
--- WEBP support ok, loaded 1.6.0
--- AVIF support ok, loaded 1.3.0
--- JPEG support ok, compiled for libjpeg-turbo 3.1.3
--- OPENJPEG (JPEG2000) support ok, loaded 2.5.4
--- ZLIB (PNG/ZIP) support ok, loaded 1.3.1.zlib-ng, compiled for zlib-ng 2.3.2
--- LIBTIFF support ok, loaded 4.7.1
*** RAQM (Bidirectional Text) support not installed
*** LIBIMAGEQUANT (Quantization method) support not installed
*** XCB (X protocol) support not installed
--------------------------------------------------------------------

Followup:
I noticed 2 to be implemented dithering options. any timeline for those?
also, hitherdither implements all of it already but is slower than Pillow. it may be a good reference though.

The issue does not name implementation files or tests. Start by locating Pillow's existing Floyd–Steinberg dithering entry point and compare its behavior with the Jarvis–Judice–Ninke matrix described here; hitherdither is offered as a reference. Done means the requested dithering option is available in Pillow and covered by appropriate tests.