Canon FB630U/FB636U manual Scanning Techniques, Matching Scan Resolution to Purpose

Ad

Page 52

S T E P 3

Scanning Techniques

Matching Scan Resolution to Purpose

ScanGear CS-U provides many choices for resolution. What resolution you choose depends 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 you need. That way, you retain the amount of information in the image, and if necessary you can reduce the resolution in the imaging application, after the image has been scanned and acquired.

Different types of images need different types of scan settings. However, after a certain point, increases in scan resolution will not improve the output image quality. For example, 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, for example, the basic resolution of the printer is halved. For example, for a 360 dpi printer the basic resolution is set for 180 dpi.

•If your image is Black & White with no shades of gray, such as line art, scan in Black and White mode.

•If you are scanning continuous-tone black and white photographs, charcoal drawings, 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 & White scan mode, more than 300 dpi is the recommended scan resolution.

•The minimum scanning width and height will vary according to the selected scan resolution. For example, at 75 dpi, the minimum size for previewing is 9 pixels 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 or 0.30 centimeter per side.

Optical and Enhanced Resolutions

Optical resolution refers to the amount of information a scanner can sample per inch. Different varieties of scanner feature different optical resolutions. The maximum optical resolution 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 (vertical dimension).

52

Image 52

Contents User’s Guide This page intentionally left blank Where to Look How to Use this GuideAbout the Conventions Used in this Guide Table of Contents Appendices Control Panel Features Scanning Procedures E PPlug-in Module CS-U Special Features See the Results of Adjustments Immediately Dynamic PreviewGamma Curve Adjusts Image Brightness Supports ColorSync 2.0 or higher Auto Tone CorrectionInstalling Plug-in Module CS-U Quick Start InstructionsStart Plug-in Module CS-U Start the Preview ScanSet the preferences, magnification and scan mode settings Specify the Area of the Image to be Scanned pClick the Browser button Select the area to be scanned by clicking and draggingScan the Image p Click the Scan buttonSave the image with the application software, specifying a Folder, file name and file formatE P Display Plug-in Module CS-U Control Panel E PE P Operating Procedures Canon PhotoSet the original on the scanner document glass PreviewingClick the Preview button Set Preferences UnitE P Setting Basic Resolution Preview Window Settings Dialog Box E P Preview Window SizeReturn to Default Settings ProceduresE P Calibration Select the Prefs menu in the control panelOutput Device Resolution= 360 dpi, Magnification= 100% Set MagnificationE P To Set the Magnification Factor Set the desired magnification factor on the control panelSet Scan Mode Black & WhiteDiffusion Dither GrayscaleColor High Definition ColorTo Set the Scan Mode Select the scan mode that you wantVerify Image Before Scanning To Verify the ImageE P Scanning Scan Area Settings Position the pointer in the preview windowTo Zoom ZoomingSelect the area you want to enlarge with the zoom function Click the Zoom In button To return to normal view, click the Zoom Out buttonTo Initiate the Scan ScanningSpecify the Scan Area Saving Scanned Images To Save an ImageColor/High Definition Mode Grayscale ModeBlack & White Mode Diffusion DitherHow to Interpret Histograms Using the Histogram Feature to Adjust Image ContrastHow to Adjust Histograms E P To Adjust a Histogram Click the Histogram buttonClick the Auto button Click the OK buttonAdjusting the Image with Gamma Settings Setting the GammaGamma = GammaContrast Brightness and Contrast SettingsBrightness E P To Adjust the Brightness and Contrast Click the Gamma buttonAdjusting Gamma with the Menu CRT Type aCRT Type B CRT Type CE P To Change the Gamma Value Settings Click the radio button for Menu SettingAdjusting the Gamma Value to Match the Display Gamma Value SettingsSending Output to a Printer Slider Tone Curve Settings Manipulating the GraphE P To Edit the Tone Curve Auto Tone Correction ColorSync To Activate the ColorSync FunctionDescreen ProcedureOpen the Image menu and select Descreen To Set the Threshold Value Set the threshold value in the Control PanelSaving / Recalling Settings To Save Settings in a Settings FileE P To Recall a Settings File Editing Scanned Images Many special effects may be achieved with filtersOptical and Enhanced Resolutions Matching Scan Resolution to PurposeScanning Techniques Functional Specifications SpecificationsSystem Requirements Problem TroubleshootingClicked on the Plug-in Module CS-U control panel Scan button cannot be selected Error Messages Error MessageCause ResponseGlossary Resolution Image FilePreview ScannerIndex P E N D I C E S Canon Customer Care Center Mail support via Canon Computer Systems, IncOE-030AA 0799 CDS Canon Inc