Canon 4.1 manual Adjusting the Threshold Value, To Set the Threshold Value

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S T E P 3

Adjusting the Threshold Value

When the scan mode is set to black and white, the image brightness can be adjusted. The threshold value setting determines whether a halftone will be expressed as a black or a white data point. The possible threshold values range between 0 and 255. Below a given threshold value, all data is converted to black. Likewise, all data with a value above the threshold is converted to white. Accordingly, higher threshold values produce darker images while lower threshold values result in brighter images.

Threshold Value = 128 (Standard)

Threshold Value = 180

Threshold Value = 70

To Set the Threshold Value

When the scan mode is set to black and white, click the [Tone Adjustment] button or pull down the Image menu and select [Tone Adjustment].

Drag the slidebar left or right to adjust the threshold setting.

Click the up or down arrow to increase or decrease the entry in the text box, or enter the value (0~255) directly from the keyboard.

After adjusting the threshold value, you can save the setting to a file under a file name and load the file again whenever you want to use the setting.

To restore the threshold setting to its default value, click this button.

Click the [OK] button.

The preview image will change to reflect the new settings.

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Contents Users Guide How to Make Best Use of the Manuals When you open the boxWhere to Look How to Use this GuideAbout the Conventions Used in this Guide Table of Contents Adjusting Scanned Images Installing Plug-in Module CS-U Operating EnvironmentControl Panel Features Pp -20Image SizeScanning Procedures E PPlug-in Module CS-U Special Features Install Plug-in Module CS-U Quick Start InstructionsStart Plug-in Module CS-U p Position materials for scanning and preview them. pVerify Image Quality with the Browser Function before Specify the Area of the Image to be ScannedSelect the area to be scanned by clicking and dragging Mouse pointer over the imageScan the Image Save the Scanned ImageClick on the Scan button Save the image with Adobe Photoshop LE or other plug-inE P Displaying the Plug-in Module CS-U Control Panel RGB ValuesOperating Procedures Positioning Originals ProceduresPlace 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 panelSetting the Scan Mode Click 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 imageOutput Device Setting PreferencesAspect Ratio Unit Preview WindowReset Default Settings Shut off lamp timeClose Plug-in After Scan Platen/FilmOperating Procedures Scanning Setting the Scan Area Position the pointer in the preview windowZooming Procedures to ZoomSelect the area you want to enlarge with the zoom function Click on the Zoom In button Scanning To Initiate the ScanSpecify the Scan Area Click close box to guit the Plug-in Module CS-USaving Scanned Images Enter a name for the file and click the Save buttonScanning Film Auto Exposure Save Exposure DataClick on the Scan button Remove Dust and Scratches CanoScan D2400U only Black & White Bit/14/16bit Grayscale and 24-bit/42/48bit ColorBit Color 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 Gamma Value =Contrast Brightness and Contrast SettingsBrightness To Adjust the Brightness and Contrast Adjusting the Color Balance Operating ProcedureMatching the Gamma Value to the Display Characteristics Gamma Value SettingsGamma value To Change the Gamma Value Settings Adjusting the Threshold Value To Set the Threshold ValueAuto Tone Correction To Set the Auto Tone CorrectionRecommended ColorSyncUnsharp Mask Open the Image menu and select Unsharp MaskDescreen Open the Image menu and select DescreenHigh-speed Scan Mode Select High-speed Scan Mode from the Image menuTo Save Settings in a Settings File Saving/Recalling SettingsClick the Save button To Recall a Settings File Matching Scan Resolution to Purpose Scanning TechniquesAppendices Troubleshooting Problem Scan button cannot be selected Problem Scanning is taking a long time Problem Scanning quality is poor Error Message Cause Error MessagesResponse Glossary Color DotOptical Resolution GrayscaleHistogram Image FileResolution PixelPlug-in Software Preview AreaScan Mode ShadowsThreshold Value Tone CurveIndex Output device 7, 11, 18, 25Scan 12, 33 Scan area 11 Canon Customer Support Help Desk Canon U.S.A., INC