Split a connected image into four grayscale channel images or choose one channel and publish that same selected channel on every output socket.
Where: Flowgen → Add → Image & Vector → Adjust → Channels
Key ideas
- Channels is one graph step: Split a connected image into four grayscale channel images or choose one channel and publish that same selected channel on every output socket.
- Typed sockets: Inputs: Image / image_in — one source image.. Outputs: Red / r_image_out.; Green / g_image_out.; Blue / b_image_out.; Alpha / a_image_out.. Settings stay on the node rather than masquerading as extra wires.
- Card and Properties agree: The compact card and selected-node Properties sidebar expose the same persisted controls: Channel: All, Red, Green, Blue, or Alpha..
- Execution behavior: This browser-local pure operation previews automatically after a short pause while a control changes, then overwrites one durable result file after the value settles. Deselecting the card or starting a downstream flow flushes the pending save. A terminal error exposes Retry; there is no normal Run button.
- Cost and privacy boundary: It calls no generation provider and charges no Sparks/Flowies. Processing happens in the open browser, so it cannot execute in a headless/server-only flow and the source must be readable by the page.
- Channels card: PureOpNode uses the authored shared-card path. Extract red, green, blue, and alpha channels as grayscale outputs.
- Properties sidebar: Card-owned operation controls; common properties shell
- Opened surfaces: Channel previews
Steps
- Connect an image.
- Choose All when different downstream branches need different channels.
- Choose one channel when every branch should inspect the same component.
- Wait for the four preview/output slots to update.
- Connect the exact named socket rather than relying on the first output.
- Use Alpha with matte tools when transparency is the signal of interest.
Inputs
- Image / image_in — one source image.
Outputs
- Red / r_image_out.
- Green / g_image_out.
- Blue / b_image_out.
- Alpha / a_image_out.
Controls
- Channel: All, Red, Green, Blue, or Alpha.
Important behavior
- All generates four outputs in R/G/B/A order.
- A single selected channel is duplicated to all four sockets so every existing downstream connection stays live.
- RGB channels are rendered as visible grayscale intensity; Alpha represents transparency coverage.
MCP authoring
- Create with create_node { type: "imageChannels" }.
- Connect exact handles with connect_nodes when the node has more than one input or output.
- Use set_props with the complete opParams bag and let the open Flowgen client preview/save it; there is no normal run_node step.
Channels controls and presets
- Add path: Flowgen → Add → Image & Vector → Adjust → Channels.
- Card: PureOpNode.
- Properties: Card-owned operation controls; common properties shell.
- Controls: All; Red; Green; Blue; Alpha.
- Opened surfaces: Channel previews.
Tips
- Test the operation on one representative asset before placing it inside a List iteration.
- Keep the untouched source upstream so the operation can be changed or bypassed later.
- Judge edges and color at the intended delivery size as well as at full preview size.
Limitations and important notes
- The node does not recombine edited channels; use Blend/Image Editor for recomposition.
- Choosing one channel does not disable the other sockets; they intentionally carry duplicates.
Troubleshooting
Every output looks identical
The Channel picker is set to a single channel. Choose All for separate R/G/B/A outputs.
FAQ
Does this open the full Image Editor?
No. This is a focused Flowgen node. Use Image Editor when you need layers, selections, paint, paths, or several edits in one document.
Can I use it in a List iteration?
Yes. Wire the current row field into the typed input, collect the exact output handle, and test one row before scaling the run.