Canon FB630U User Manual

Also see for CanoScan FB 630U: Service manual User guide User guide Product guide

Contents

Canon FB630U User Manual Manual pdf 58 page image

58S T E P 4Scanning TechniquesMatching Scan Resolution to PurposeScanGear CS-U provides many choices for resolution. What resolution you choosedepends on your output device, how you want to use the image, the type of image,and your scanner.In general, it is recommended that you scan the image at a higher resolution than youneed. That way, you retain the amount of information in the image, and if necessaryyou can reduce the resolution in the imaging application, after the image has beenscanned and acquired.Different types of images need different types of scan settings. However, after a certainpoint, increases in scan resolution will not improve the output image quality. Forexample, a text image can be scanned at 600 dpi for output to a 600 dpi laser printer,but a color image should be scanned at 180 dpi to be output to a color BJ-printer.When the image is output to a Bubble jet printer in the color or grayscale mode, forexample, the basic resolution of the printer is halved. For example, for a 360 dpi printerthe basic resolution is set for 180 dpi.• If your image is black and white with no shades of gray, such as line art, scanin Black and White mode.• If you are scanning a text image for conversion into editable text, scan in Textmode.• If you are scanning continuous-tone black and white photographs, charcoaldrawings, or any original with shades of gray, scan in Grayscale mode.• For full-color images, such as photographs or illustrations, scan in Color mode.• With OCR applications using black and white scan mode, more than 300 dpi isthe recommended scan resolution.• The minimum scanning width and height will vary according to the selectedscan resolution. For example, at 75 dpi, the minimum size for previewing is 9pixels per side, which is approximately 0.12 inch or 0.30 centimeter per side.The minimum at 300 dpi is 35 pixels, which is also approximately 0.12 inch or0.30 centimeter per side.Optical and Enhanced ResolutionsOptical resolution refers to the amount of information a scanner can sample per inch.Different varieties of scanner feature different optical resolutions. The maximum opticalresolution of the CanoScan FB630U or FB636U is 600 dpi for the primary scan(horizontal dimension of the document) and 1200 dpi for the secondary scan (verticaldimension).