Canon FB630U, FB636U manual Gamma =

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S T E P 4

The Relationship Between the Gamma Curve and Image Brightness

Gamma curve values fall with a range of 0.01 to 10.00. A gamma value of 1 appears as a straight line in the gamma graph, and if the value is any value other than one, the line on the gamma graph will appear curved. The relationship between the shape of the gamma curve and image brightness is explained below.

Gamma = 1

Input and output and are equal	Output
Input and output and are equal
and the gamma curve appears as
a straight line, and the input
image is displayed on the screen
without adjustment.

Gamma < 1

The data bends upward from the	Output
The data bends upward from the
input shadow to highlight into
the output area bending the curve
up and making the adjusted
image brighter in the display.

Gamma > 1

the input shadow to highlight	Output
The data bends downward from
away from the output area
bending the curve down and
making the adjusted image darker
in the display.

➟

Input

➟

Input

➟

Input

CAUTION

•The gamma curve cannot be adjusted for a high definition color image that has been set with ColorSync because the tone adjustment is performed automatically.

•The gamma curve cannot be adjusted for a Black & White (Line) image because mid-tones are shown as either black or white. To adjust the brightness of a Black & White image, use the threshold setting. (p. 54)

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Image 43

Contents Users Guide Getting Started How to Make Best Use of the ManualsWhere to Look How to Use this GuideAbout the Conventions Used in this Guide Table of Contents Appendices Adjusting and Editing Scanned ImagesControl Panel Features Scanning Preparations p Scanning ProceduresAdjusting and Editing Scanned Images E PSupports ColorSync 2.0 or higher Auto Tone Correction Plug-in Module CS-U Special FeaturesSee the Results of Adjustments Immediately Dynamic Preview Gamma Curve Adjusts Image BrightnessStart the Preview Scan Installing Plug-in Module CS-UQuick Start Instructions Start Plug-in Module CS-USelect the area to be scanned by clicking and dragging Set the preferences, magnification and scan mode settingsSpecify the Area of the Image to be Scanned p Click on the Browser buttonFolder, file name and file format Scan the Image pClick on the Scan button Save the image with the application software, specifying aE P E P Installing Plug-in Module CS-UOperating Environment Click the Install the Software button E P ProceduresClick the Yes button to start the installation E P E P Scanning Preparations Buttons Display Plug-in Module CS-U Control PanelAdobe PhotoDeluxe E P Operating ProceduresAdobe Photoshop Set the original on the scanner document glass PreviewingClick on the Preview button Unit Set PreferencesE P Setting Basic Resolution E P Preview Window Size Preview Window Settings Dialog BoxSelect the desired option from the pull-down menu Return to Default SettingsE P Calibration Select the Prefs menu in the control panelSet Magnification Output Device Resolution= 360 dpi, Magnification= 100%Set the desired magnification factor on the control panel E P To Set the Magnification FactorGrayscale Mode 8-bit Set Scan ModeBlack and White Mode Line Black and White Mode Diffusion DitherHigh Definition Color Color Mode 24-bitSelect the scan mode that you want To Set the Scan ModeTo Verify the Image Verify Image Before ScanningE P Scanning Position the pointer in the preview window Scan Area SettingsTo Zoom ZoomingSelect the area you want to enlarge with the zoom function To return to normal view, click the Zoom Out button Click on the Zoom In buttonTo Initiate the Scan ScanningSpecify the Scan Area To Save an Image Saving Scanned ImagesDiffusion Dither Color ModeGrayscale Mode Black & White ModeHow to Interpret Histograms Using the Histogram Feature to Adjust Image ContrastHow to Adjust Histograms Click on the OK button E P To Adjust a HistogramClick on the Histogram button Click the Auto buttonSetting the Gamma Adjusting the Image with Gamma SettingsGamma Gamma =Contrast Brightness and Contrast SettingsBrightness Click the gamma button E P To Adjust the Brightness and ContrastClick the OK button CRT Type C Adjusting Gamma with the MenuCRT Type a CRT Type BClick the radio button for Menu Setting E P To Change the Gamma Value SettingsAdjusting the Gamma Value to Match the Display Gamma Value SettingsSending Output to a Printer Slider Manipulating the Graph Tone Curve SettingsE P To Edit the Tone Curve To Activate the ColorSync Function Auto Tone Correction ColorSyncDescreen ProcedureOpen the Image menu and select Descreen Set the threshold value in the Control Panel To Set the Threshold ValueTo Save Settings in a Settings File Saving / Recalling SettingsE P To Recall a Settings File Many special effects may be achieved with filters Editing Scanned ImagesOptical 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 Response Error MessagesError Message CauseGlossary Scanner ResolutionImage File PreviewIndex P E N D I C E S Helpdesk Canon Customer Support Help DeskOE-030AA 0799 CDS Canon Inc