Image Select Channel

Every RGB image is really three grayscale layers stacked together - red, green, and blue intensity maps riding as one file. Per the README, this node "selects a single channel of an RGB image," pulling just one of those three out on its own so you can look at it, edit it, or use it independently of the other two.

The natural pair: Image Mix RGB Channels

This node is one half of a split-edit-recombine loop the pack sets up on purpose. Image Mix RGB Channels does the opposite job - it takes three separate channel images and stacks them back into one full-color image. Together they let you do things to individual color channels that you simply can't do to a whole image at once: blur only the blue channel, boost contrast on green alone, or deliberately misalign channels for a chromatic-aberration-style glitch look, then recombine.

Why you'd want a single channel

A few real reasons this comes up: inspecting which channel actually carries the useful detail or noise in an image (blue channels are often noisier than red or green, a fact that matters if you're doing careful compositing work), feeding a single-channel grayscale image into something that expects a mask-like input, or as the first step of the split-edit-recombine pattern above.

The inputs and outputs that matter

An image in, a choice of which channel - red, green, or blue - and a single-channel image out (typically rendered as grayscale, since it's just that one channel's intensity values with no color information left to show). Wire that output into whatever you're editing it with, then back into Image Mix RGB Channels if you're planning to reassemble.

How to install it

Bundled with the full WAS Node Suite:

• ComfyUI Manager - search "WAS Node Suite", install, restart.
• Manual - cd ComfyUI/custom_nodes && git clone https://github.com/WASasquatch/was-node-suite-comfyui, install requirements.txt (portable: python_embeded\python.exe -s -m pip install -r requirements.txt), restart.

No model, no heavy dependency - a plain pixel operation.

Common issues & troubleshooting

Recombined image looks wrong after a round-trip through channel editing. If you're pairing this with Image Mix RGB Channels later, keep the dimensions of every channel identical through whatever editing happens in between - resize one channel and not the others, and the recombine either errors or produces garbage, since there's no sensible way to overlay grids of different sizes.

Picked the wrong channel by mistake. Easy to do, and the output - a grayscale image - doesn't visually announce which channel it came from. If a downstream effect looks off, double-check you selected the channel you actually meant to isolate.

Standard pack caveat: WAS Node Suite has been unmaintained since December 2023, and the recurring issue is the whole suite failing to import after a ComfyUI update - a dependency-version clash, not this node specifically. Reinstall requirements.txt against the right Python environment if the suite won't load.