### ImageMagick version

7.1.1-25

### Operating system

Linux

### Operating system, version and so on

NixOS 23.11.3409.d7f206b723e4 (Tapir)

### Description

According to [the documentation on the `-dither` command line option](https://imagemagick.org/script/command-line-options.php#dither) and [the color quantization examples page](https://www.imagemagick.org/Usage/quantize/#posterize), the `-posterize` option should use the current dither setting when reducing the color space. However, as of right now, it doesn't seem to do any dithering at all.

### Steps to Reproduce

1. Run a command with a `-dither` option and a `-posterize` option - for example: `magick Parrot.red.macaw.1.arp.750pix.jpg -dither FloydSteinberg -posterize 2 Parrot-posterize2-fs.png`

Expected result: A posterized image using the appropriate dither setting.

Observed result: An undithered posterized image.

### Images

Using [Adrian Pingstone's macaw picture](https://commons.wikimedia.org/wiki/File:Parrot.red.macaw.1.arp.750pix.jpg) for demonstration:
![Parrot red macaw 1 arp 750pix](https://github.com/ImageMagick/ImageMagick/assets/11142302/26d11106-9cf1-4322-8cda-5a85098f9033)

`magick Parrot.red.macaw.1.arp.750pix.jpg +dither -posterize 2 Parrot-posterize2-none.png`
![Parrot-posterize2-none](https://github.com/ImageMagick/ImageMagick/assets/11142302/3b93db2b-7d61-4995-bdef-6a756866c41a)

`magick Parrot.red.macaw.1.arp.750pix.jpg -dither FloydSteinberg -posterize 2 Parrot-posterize2-fs.png`
![Parrot-posterize2-fs](https://github.com/ImageMagick/ImageMagick/assets/11142302/895d13a2-3d48-456e-b8d6-ce23df5835cc)

`magick Parrot.red.macaw.1.arp.750pix.jpg -dither FloydSteinberg -remap RGB_3bits_palette_color_test_chart.png Parrot-remap-fs.png`
![Parrot-remap-fs](https://github.com/ImageMagick/ImageMagick/assets/11142302/acc768aa-6f02-4934-b785-5c89d0e2b7c2)

posterize command line option is ignoring dither option
This is a GitHub Issue
repo:ImageMagick
owner:ImageMagick
Title : posterize command line option is ignoring dither option
Issue date:

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### ImageMagick version

7.1.1-25

### Operating system

Linux

### Operating system, version and so on

NixOS 23.11.3409.d7f206b723e4 (Tapir)

### Description

According to [the documentation on the `-dither` command line option](https://imagemagick.org/script/command-line-options.php#dither) and [the color quantization examples page](https://www.imagemagick.org/Usage/quantize/#posterize), the `-posterize` option should use the current dither setting when reducing the color space. However, as of right now, it doesn't seem to do any dithering at all.

### Steps to Reproduce

1. Run a command with a `-dither` option and a `-posterize` option - for example: `magick Parrot.red.macaw.1.arp.750pix.jpg -dither FloydSteinberg -posterize 2 Parrot-posterize2-fs.png`

Expected result: A posterized image using the appropriate dither setting.

Observed result: An undithered posterized image.

### Images

Using [Adrian Pingstone's macaw picture](https://commons.wikimedia.org/wiki/File:Parrot.red.macaw.1.arp.750pix.jpg) for demonstration:
![Parrot red macaw 1 arp 750pix](https://github.com/ImageMagick/ImageMagick/assets/11142302/26d11106-9cf1-4322-8cda-5a85098f9033)

`magick Parrot.red.macaw.1.arp.750pix.jpg +dither -posterize 2 Parrot-posterize2-none.png`
![Parrot-posterize2-none](https://github.com/ImageMagick/ImageMagick/assets/11142302/3b93db2b-7d61-4995-bdef-6a756866c41a)

`magick Parrot.red.macaw.1.arp.750pix.jpg -dither FloydSteinberg -posterize 2 Parrot-posterize2-fs.png`
![Parrot-posterize2-fs](https://github.com/ImageMagick/ImageMagick/assets/11142302/895d13a2-3d48-456e-b8d6-ce23df5835cc)

`magick Parrot.red.macaw.1.arp.750pix.jpg -dither FloydSteinberg -remap RGB_3bits_palette_color_test_chart.png Parrot-remap-fs.png`
![Parrot-remap-fs](https://github.com/ImageMagick/ImageMagick/assets/11142302/acc768aa-6f02-4934-b785-5c89d0e2b7c2)

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