ImageGear v26.3 - Updated November 9, 2022
ImageGear.Core Assembly / ImageGear.Processing Namespace / ImGearRasterProcessing Class / AdjustContrast Method / AdjustContrast(ImGearRasterPage,Double,Double,Double) Method
Image to adjust contrast.
Contrast value.
Brightness value.
Gamma value.




AdjustContrast(ImGearRasterPage,Double,Double,Double) Method
Adjusts contrast, brightness, and gamma.
Syntax
'Declaration
 
Public Overloads Shared Sub AdjustContrast( _
   ByVal page As ImGearRasterPage, _
   ByVal contrast As Double, _
   ByVal brightness As Double, _
   ByVal gamma As Double _
) 
 
'Usage
 
Dim page As ImGearRasterPage
Dim contrast As Double
Dim brightness As Double
Dim gamma As Double
 
ImGearRasterProcessing.AdjustContrast(page, contrast, brightness, gamma)

Parameters

page
Image to adjust contrast.
contrast
Contrast value.
brightness
Brightness value.
gamma
Gamma value.
Remarks
If the image is indexed and not grayscale, it modifies the image's palette, otherwise it modifies the image's pixels. Processes only color channels. Contrast mode is ImGearContrastModes.AUTO.

Average parameter range:

  • Contrast: -2 ... +2 (negative means contrast inversion. In case of 1 no changes)
  • Brightness: -128...+128
  • Gamma: 0...10

Can be applied only to the raster pages with standard (non Run-Ends) DIB.

Method ImGearRasterProcessing.Verifier.CanApplyAdjustContrast (ImGearPage page) can be called to check whether the operation can be performed.

Example
See Also