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Channel Merge

Channel Merge
Color

Combines up to four single-channel images into one RGBA image, with per-channel fill defaults for any unconnected input.

Three grayscale maps of a rusty diamond tread plate, Ambient Occlusion, Roughness and Metallic, stacked as labeled strips, beside the one color map Channel Merge packs from them: AO in red, Roughness in green and Metallic in blue, so the bare steel treads and the rust read in different colors

Each input is optional, but at least one must be connected, and all connected inputs must share the same dimensions (the output matches them). An unconnected channel is filled with Zero, One, or a Custom value from 0 to 255. The defaults are Zero for R, G, and B and One for alpha, so a single wired channel still gives an opaque image.

Channel Merge is the inverse of Channel Split. It also accepts the single-channel output of nodes like Mask From Image, Mask Paint, Mask Refine, Magic Wand, or Color Range.

Parameters

Section titled “Parameters”

Pins

RMask
InputOptional
GMask
InputOptional
BMask
InputOptional
AMask
InputOptional
ImageImage
Output

Red Channel

Red FillChoice
Default: Zero Range: Zero / One / Custom
When red input is not connected

Fill mode for the red channel when not connected

Red ValueInteger
Default: 0 Range: 0–255
When fill mode == Custom

Constant value used to fill the red channel

Green Channel

Green FillChoice
Default: Zero Range: Zero / One / Custom
When green input is not connected

Fill mode for the green channel when not connected

Green ValueInteger
Default: 0 Range: 0–255
When fill mode == Custom

Constant value used to fill the green channel

Blue Channel

Blue FillChoice
Default: Zero Range: Zero / One / Custom
When blue input is not connected

Fill mode for the blue channel when not connected

Blue ValueInteger
Default: 0 Range: 0–255
When fill mode == Custom

Constant value used to fill the blue channel

Alpha Channel

Alpha FillChoice
Default: One Range: Zero / One / Custom
When alpha input is not connected

Fill mode for the alpha channel when not connected (default: One)

Alpha ValueInteger
Default: 0 Range: 0–255
When fill mode == Custom

Constant value used to fill the alpha channel

Mask

Mask FromChoice
Default: Luminance
Color image connected to the mask input

How the connected color image is read as a mask

  • LuminanceRead the image's brightness as the mask. The default.
  • AlphaRead the image's transparency as the mask.
  • RedUse the red channel as the mask.
  • GreenUse the green channel as the mask.
  • BlueUse the blue channel as the mask.

Usage Tips

Section titled “Usage Tips”
  • Pair with Channel Split to process channels individually and recombine, for example to blur only the alpha or curve only the red channel.
  • Wire a single channel into R and leave the rest on their defaults to view it as a red-on-black image.
  • Assemble a normal map from separately processed channels by wiring them into R, G, and B, with Alpha left on One. To generate a normal map from a height map, use Normal Map instead.
  • Use a Custom fill (for example 128) to set a channel to a fixed neutral instead of black or white.
Section titled “Related Nodes”