Canon N656U, N1220U, N650U manual Scanning Techniques, Matching Scan Resolution to Purpose

Page 54

S T E P 3

Scanning Techniques

Matching Scan Resolution to Purpose

Plug-in Module CS-U provides many choices of resolution. The resolution you choose should depend upon your output device, the intended purpose of the image, the type of image and your scanner.

It is generally recommended that you scan at a higher resolution than required for output. This ensures that you obtain the best quality image, which can then be reduced with an image editing program to suit specific purposes.

Different types of images require different scan settings. However, increases in scan resolution have a diminishing return after a certain point. For example, a text image can be scanned at 600 dpi for output to a 600 dpi laser printer, while a color image should be scanned at 180 dpi to be output to a color bubble jet printer (360 dpi). To output a color or grayscale image to a bubble jet printer, use a resolution equal to half the resolution of the printer. Set the resolution to 180 dpi, for example, for output on a 360 dpi printer.

•Scan in black and white mode if you are scanning line art or other items that are black and white with no shades of gray.

•Scan in black and white mode if you are scanning a text image for conversion to editable text.

•Scan in grayscale mode if you are scanning continuous-tone black and white photographs, charcoal drawings or originals with shades of gray.

•Scan in Color (Photos) mode if you are scanning full-color images, such as photographs or illustrations.

•Scan in Color (Documents) mode if you are scanning items that include text or charts at a low resolution. It may take some time to scan in this mode.

•If you are using an OCR (optical character reader) program in black and white mode, you are recommended to select a resolution higher than 300 dpi.

•The minimum scannable height and width will vary with the scanning resolution. At 75 dpi, for example, the minimum selectable height and width in the preview area is 9 pixels (approximately 0.12 inches or 0.30 cm). At 300 dpi, it is 35 pixels (approximately 0.12 inches or 0.30 cm).

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 N650U/N656U models is 600 dpi for the primary scan (horizontal dimension of the document), and 1200 dpi for the secondary scan (vertical dimension). The CanoScan N1220U optical resolution is 1200 dpi for the primary scan and 2400 dpi for the secondary scan.

54

Page 53 Page 55
Image 54
Page 53 Page 55
Contents Users Guide How to Make Best Use of the Manuals When you open the boxHow to Use this Guide Where to LookAbout the Conventions Used in this Guide Table of Contents Adjusting Scanned Images Installing Plug-in Module CS-U Operating EnvironmentControl Panel Features Image Size ppScanning Procedures E PGamma Curve Adjusts Image Brightness Plug-in Module CS-U Special FeaturesSee the Results of Adjustments Immediately Dynamic Preview ColorSync Ver 2.0 + Compatible for Auto Tone CorrectionStart Plug-in Module CS-U Install Plug-in Module CS-UQuick Start Instructions Position materials for scanning and preview themClick on the Browser button Selection frame will appear Verify Image Quality with the Browser Function beforeSpecify the Area of the Image to be Scanned Select the area to be scanned by clicking and draggingScan the Image p Save the Scanned Image pE P Displaying the Plug-in Module CS-U Control Panel RGB ValuesOperating Procedures Procedures Positioning OriginalsPlace the original on the scanners document glass Previewing Click on the Preview buttonSelecting the Output Device Setting the Resolution and Magnification Output Device Resolution= 720 dpi, Magnification= 100%To Set the Magnification Factor Set the desired magnification factor on the control panelGrayscale Setting the Scan ModeBlack and White Color DocumentsClick the arrow beside Scan Mode Select a scan mode from the pop-up menuVerifying the Image before Scanning To Verify the ImageRotating the Image Use these buttons to rotate the imageSetting Preferences Output DeviceAspect Ratio Unit Preview WindowReset Default Settings CalibrationClose Plug-in After Scan Operating Procedures Scanning Setting the Scan Area Position the pointer in the preview windowProcedures to Zoom ZoomingSelect the area you want to enlarge with the zoom function Click on the Zoom In button Specify the Scan Area ScanningTo Initiate the Scan Click on the Scan buttonSaving Scanned Images Enter a name for the file and click the Save buttonGrayscale, Color Photos and Color Documents Black & WhiteColor Photos and Color Documents Tone Adjustment Tone Adjustment DialogHistogram Settings How to Interpret HistogramsTo Adjust a Histogram How to Adjust HistogramsClick on the OK button Shadow MarkTone Curve Settings Manipulating the GraphTo Edit the Tone Curve Click the OK buttonRelationship Between the Tone Curve Image Brightness Value =Brightness and Contrast Settings ContrastBrightness To Adjust the Brightness and Contrast Adjusting the Color Balance Operating ProcedureGamma Value Settings Matching the Gamma Value to the Display CharacteristicsGamma value To Change the Gamma Value Settings Adjusting the Threshold Value To Set the Threshold ValueStandard Auto Tone CorrectionTo Set the Auto Tone Correction ColorSyncUnsharp Mask Open the Image menu and select Unsharp MaskDescreen Open the Image menu and select DescreenSaving/Recalling Settings To Save Settings in a Settings FileClick the Save button To Recall a Settings File Matching Scan Resolution to Purpose Optical and Enhanced ResolutionsScanning Techniques Appendices Troubleshooting Problem Scan button cannot be selected Cause Error MessagesError Message ResponseBits/Bit Numbers GlossaryAuto Tone Correction Black Eyedropper ToolColor Channel DotHistogram Image FileMagnification Moiré Optical ResolutionResolution PixelThreshold Value Scan ModeShadows Tone CurveIndex Output device 7, 11, 18, 25Page Canon Customer Support Help Desk Canon Computer SYSTEMS, INCOE-040AA 052000 CDS Canon Inc
Top Page Image Contents