ColorSpace Gamma Property. The gamma correction for the color space. ABCpdf .NET PDF Library.

The gamma correction for the color space.

This property is only valid for color spaces in which the ColorSpaceType is CallGray or CalRGB.

Gamma is defined for each component of a calibrated color space. So for a CalGray color space it has one entry and for a CalRGB color space it has three.

This means that for a CalGray color space this property will be a NumAtom and for a CalRGB color space it will be an ArrayAtom with three entries.

Each gamma entry must be positive and is generally greater than or equal to one.

In this example we show how to use the Gamma property with a calibrated grayscale color space.

[C#]
using (Doc doc = new Doc()) {
  doc.Width = 80;
  doc.Rect.Inset(50, 50);
  ColorSpace cs = new ColorSpace(doc.ObjectSoup, ColorSpaceType.CalGray);
  ((NumAtom)cs.Gamma).Real = 1.2;
  doc.ColorSpace = cs.ID;
  doc.Color.SetComponents(0.9); // gray
  doc.AddOval(true);
  doc.Save("examplecalgraycolorspace.pdf");
}

[Visual Basic]
  Using doc As New Doc()
    doc.Width = 80
    doc.Rect.Inset(50, 50)
    Dim cs As New ColorSpace(doc.ObjectSoup, ColorSpaceType.CalGray)
    DirectCast(cs.Gamma, NumAtom).Real = 1.2
    doc.ColorSpace = cs.ID
    doc.Color.SetComponents(0.9)
    ' gray
    doc.AddOval(True)
    doc.Save("examplecalgraycolorspace.pdf")
  End Using
End Sub


examplecalgraycolorspace.pdf