8.15. Compose

8.15.1. Overview

Figure 15.150. Example for the Compose command

Example for the Compose command

Decomposed image (RGB decomposition)

Example for the Compose command

Compose applied


This command constructs an image from several grayscale images or layers, for instance from extracted RGB, HSV... components. You can also build an image from grayscale images or layers created independently.

8.15.2. Activate the command

  • You can find this command in the image window menu under ColorsComponentsCompose…. It is enabled if your image is grayscale.

8.15.3. Options

Figure 15.151. Compose command options

Compose command options

Compose Channels

You can select there the color space to be used: RGB, HSV... The options are described in the following Decompose command.

Channel Representation

Allows you to select which channel will be affected to each image channel. You may use this option, for example, to exchange color channels:

Figure 15.152.  Channel Representation example: exchange two channels

Channel Representation example: exchange two channels

Original image

Channel Representation example: exchange two channels

Decomposed to layers

Channel Representation example: exchange two channels

Applied Channel Representation

Channel Representation example: exchange two channels

Composed image


Mask Value: Instead of selecting a layer or an image to build the channel, you can give the channel a value from 0 to 255. But note that at least one channel must be formed from a layer or image.

[Tip] Tip

If Compose options are different from Decompose ones, for instance an image decomposed to RGB then re-composed to LAB, you will get interesting color effects. Test it!