Inspect RGB channels and alpha/selection information, then use the histogram to evaluate the current composite.
Where: Image Editor → Channels panel or Histogram panel in the workspace panels.
Key ideas
- Channel inspection is not a pixel edit: Component-channel display changes how you inspect the composite. It does not permanently recolor the document. Return to the composite view before judging the final image.
- Color channels versus masks: RGB components describe image color. Alpha and saved selection channels describe coverage. Keep those purposes separate when loading a channel as a selection or comparing a mask to visible artwork.
- Histogram reflects the composite: The histogram analyzes a rendered composite snapshot and offers RGB, R, G, and B views. It updates with document revisions; it is not a histogram of an arbitrary hidden source layer or a guarantee of full-resolution numerical sampling.
Steps
- Open Channels and inspect the composite before isolating a component. Note whether you are looking at RGB color or a coverage channel.
- Choose a component view to inspect channel detail, then return to the full composite to confirm the intended appearance.
- Use the selection/channel actions only when you intend to change the active selection or saved alpha data.
- Open Histogram, choose RGB or a single color component, and inspect the distribution while adjusting the image.
- Wait for the latest snapshot after an edit. If analysis is unavailable, do not mistake a stale or blank panel for an image with no tonal data.
- Review the normal composite and export preview after the diagnostic work is complete.
What each panel answers
- Channels: what contributes to a component or coverage region, and which channel is being inspected.
- Histogram: how the current visible composite distributes pixel values across the chosen channel.
- Layers: which objects, masks, adjustments, and effects build that composite.
- Changing a panel’s display mode does not replace the need to select the intended layer or mask before painting.
Large-image behavior
Histogram snapshots are planned with a bounded analysis size to keep large documents usable. Use the display for visual diagnosis, not as a claim that every source pixel was individually sampled. Browser/GPU pressure can delay or prevent a snapshot; the panel reports unavailable analysis rather than inventing a result.
Troubleshooting
The image looks monochrome after inspecting a channel.
Return Channels to the RGB composite view before editing color.
The histogram does not match a hidden layer.
It measures the rendered composite. Isolate the layer deliberately if that is the image you want to inspect, then wait for the updated snapshot.