User Guide

Canvas 12 User Guide
To constrain the height and width of the cropping rectangle symmetrically from the
center: Release the Ctrl key and then press it again while dragging.
To constrain the height and width of the cropping rectangle both proportionally and
symmetrically: Release the Ctrl key and then press Ctrl+Shift while dragging.
Changing resolution
Change the resolution of paint objects in two ways:
If you do not want to change an object’s size, resample the image. Resampling merges or
divides pixels.
If you want to preserve all the data in an image, change the object’s resolution and allow its
size to change.
Decreasing resolution (“down sampling”) decreases file size by discarding data, which can result in
lost detail; however, it’s common to reduce resolution in some situations.
For Web pages and other applications where images are displayed on a monitor, 72 ppi is
the standard resolution.
Rarely, an image is resampled to increase resolution. This should be avoided because additional
pixels are created by estimating their color values, which does not improve an image.
The Resolution dialog box has compact and expanded states. In its compact state, you can easily
change the resolution of multiple paint objects without needing to specify additional options (see
"Image resolution settings" on page 456).
Image resolution settings
Specify the resolution, width, and height for a selected paint object when the Image Resolution dialog
box is expanded. Expand the dialog box when a single paint object is selected; if multiple objects are
selected, they must match in size and resolution.
Depending on the options you select, certain settings in the dialog box can’t be changed. A bracket
and chain icon indicate settings that are linked and fixed.
Preserve Data: Prevents resampling, or interpolation, when resolution or size changes.
Selecting Preserve Data also selects Preserve Proportions, so width and height change only in
proportion to each other.
Preserve Data means image resolution and size are relative; changing the resolution will change
the object size, and changing the size will change the image resolution.
456