Deciding on a scanning resolution Digital images are composed of square pixels, and pixel size is a major factor affecting image quality. The resolution of an image is expressed as the number of pixels per (linear) inch, abbreviated ppi, or pixels per centimeter. Smaller pixels result in higher image resolu- tion, which generally indicates better image quality. With scanned images, the resolution is also a measure of how much information has been captured from the original artwork. At relatively low resolution, such as 75 ppi, lines, edges, and charac- ter shapes in an image can appear jagged (see “About digital images and resolution” on page 32.637). Scanning at higher resolution pro- duces smoother images, which also require more memory and disk space. Use the following questions to help you decide what resolution is appropriate when you scan images. B A C Scanning options Plug-in acquire modules for scanners offer various options. Some standard scanning options are described here. Scan Mode or Color Mode. Choose color, black and white, or grayscale. These options correspond to the RGB Color, Grayscale, and Black & White image modes in Canvas. Resolution. Specify the scan resolution in pixels (or dots) per inch. Scanning at higher resolution captures more image information and results in higher memory and disk storage requirements. Scaling. Enter a scaling per- centage to reduce or enlarge the image. A Use the preview area to check the image and make sure the area you want to scan is po- sitioned correctly. B Many scanners let you drag the corner of a scan rectangle to select the area that will be scanned. The selected area de- termines the size of the image object in Canvas. C    Most scanners offer bright- ness or exposure controls. Refer to the scanner documentation for more information on adjust- ing exposure settings.
Canvas 8 Help: Scanning, sizing, and tracing images (4 of 18)                                       Page #636