User Guide

Chapter 5: Painting And Image Editing
When an image object is in envelope edit mode, its bounding box acts like the rubber sheet. Canvas
includes several envelope styles that offer various handles you can use to manipulate an object’s
bounding box.
To learn about the envelope styles and their respective uses, see "Enveloping objects" on page 384.
Original image
Enveloped image
Combining image channels
The Calculate Image command lets you combine channels to create selection masks for effects like
embossing text in an image. By adding, subtracting, and multiplying channels, you can also enhance
shadows and highlights. The Calculate Image command combines corresponding pixels from two
channels by the method you choose. You can place the result in a new or existing channel.
As shown in "Examples of Calculate blending options" on page 550, you can also copy an
image and paste it into a new alpha channel of Source 1. Then use the Calculate Image
command to combine Source 1 and the new alpha channel (Source 2).
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