expression.IncrementBrightness(Increment)
expression Required. An expression that returns one of the objects in the Applies To list.
Increment Required Single. Specifies how much to change the value of the Brightness property for the picture. A positive value makes the picture brighter; a negative value makes the picture darker. Valid values are between – 1 and 1.
Remarks
You cannot adjust the brightness of a picture past the upper or lower limit for the Brightness property. For example, if the Brightness property is initially set to 0.9 and you specify 0.3 for the Increment argument, the resulting brightness level will be 1.0, which is the upper limit for the Brightness property, instead of 1.2.
Use the Brightness property to set the absolute brightness of the picture.
Example
This example creates a duplicate of the first shape in the active publication and then moves and darkens the duplicate. For the example to work, the shape must be either a picture or an OLE object representing a picture.
With ActiveDocument.Pages(1).Shapes(1).Duplicate
.PictureFormat.IncrementBrightness Increment:=-0.2
.IncrementLeft Increment:=50
.IncrementTop Increment:=50
End With