The width and height boxes show the size a paint object will become if you change the resolution when Preserve Data is selected. Preserve Proportions This option links the Width and Height val- ues so that changing one value changes the other and maintains the original proportions of the paint object. Selecting Preserve Data also selects this option. If you want to stretch a paint object in only one direction, you must deselect Preserve Proportions. To specify how Canvas approximates new pixels When increasing image resolution, Canvas uses one of two methods to calculate color values for the pixels it adds to an image. To change the method, use the Preferences command. Original 300 ppi Resampled down to 150 ppi 150 ppi image with Unsharp Mask filter applied Amount = 80 Radius = 1.6 Threshold = 0 300 ppi image with Unsharp Mask filter applied Amount = 67 Radius = 1.6 Threshold = 0 150 ppi image resampled up to 300 ppi Resampling and sharpening images Resizing and resampling causes images to appear softer. However, you can apply the Unsharp Mask filter to bring soft images back into focus. For more informa- tion, see “To apply the Unsharp Mask filter” on page 34.702.
Canvas 8 Help: Scanning, sizing, and tracing images (13 of 18)                                      Page #645