Brightness

This algorithm adjusts the brightness of specified image in RGB color space. This algorithm works by increasing every pixel's RGB values by the specified adjust value.

   

• C#
• VB.Net

									Public Shared Sub ApplyBrightness(ByRef bmp As Bitmap, brightnessValue As Byte)
	Dim bmpData As BitmapData = bmp.LockBits(New Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb)
	Dim ptr As IntPtr = bmpData.Scan0
	Dim stopAddress As Integer = CInt(ptr) + bmpData.Stride * bmpData.Height

	Dim val As Integer = 0

	While CInt(ptr) <> stopAddress
		val = Marshal.ReadByte(ptr + 2) + CInt(brightnessValue)
		If val < 0 Then
			val = 0
		ElseIf val > 255 Then
			val = 255
		End If
		Marshal.WriteByte(ptr + 2, CByte(val))

		val = Marshal.ReadByte(ptr + 1) + CInt(brightnessValue)
		If val < 0 Then
			val = 0
		ElseIf val > 255 Then
			val = 255
		End If
		Marshal.WriteByte(ptr + 1, CByte(val))

		val = Marshal.ReadByte(ptr) + CInt(brightnessValue)
		If val < 0 Then
			val = 0
		ElseIf val > 255 Then
			val = 255
		End If
		Marshal.WriteByte(ptr, CByte(val))

		ptr += 3
	End While

	bmp.UnlockBits(bmpData)
End Sub
								

Example

									DIm b As Bitmap = CType(Image.FromFile("rose.jpg"), Bitmap)
ApplyBrightness(b, 50)