Newtone.ImageKit.Effect.StartBitmapAccess Method

The StartBitmapAccess method is used to allow access to pixels in the Device Independent Bitmap (DIB). This method is to be used in conjunction with the EndBitmapAccess method.

Parameters

imgNo
     The image number (from -1 to 99)

Return Value

Returns True if successful. Returns False if unsuccessful.

Explanation

The StartBitmapAccess method is used to allow access to pixels in the Device Independent Bitmap (DIB). This method is to be used in conjunction with the EndBitmapAccess method.

To execute the StartBitmapAccess method, set the image handle of the image in the SourceImage property. This method supports 1, 4, 8, 16, 24, and 32 bit images.

To access the DIB and manipulate pixel data, you must use the following methods as a group:

StartBitmapAccess
      |
GetBitmapPixel, SetBitmapPixel
      |
EndBitmapAccess

Example

The following code starts access to the DIB, then loops through each pixel in the image, using the GetBitmapPixel method to retrieve the pixels' rgb values. Then those values are reversed and set using the SetBitmapPixel method (For 1, 16, 24, or 32 bit images).

[Visual Basic]
Dim IkEffect As Newtone.ImageKit.Effect
Dim Ret As Boolean
Dim i As Long, j As Long
Dim PalNo As Integer, Red As Integer, Green As Integer, Blue As Integer

IkEffect = New Newtone.ImageKit.Effect

If IkEffect.SourceImage = Nothing Then Exit Sub
Ret = IkEffect.StartBitmapAccess(0)
If Ret = False Then Exit Sub                            

For i = 0 To IkEffect.SourceImage.Height - 1
  For j = 0 To IkEffect.SourceImage.Width - 1
    Ret = IkEffect.GetBitmapPixel(0, j, i, PalNo, Red, Green, Blue)
    If Image.GetPixelFormatSize(IkEffect.SourceImage.PixelFormat) = 1 Then
      If PalNo <> 0 Then
        PalNo = 0
      Else
        PalNo = 1
      End If
    Else If Image.GetPixelFormatSize(IkEffect.SourceImage.PixelFormat) > 8 Then
      Blue = 255 - Blue
      Green = 255 - Green
      Red = 255 - Red
    End If
    Ret = IkEffect.SetBitmapPixel(0, j, i, PalNo, Red, Green, Blue)
  Next j
Next i

Ret = IkEffect.EndBitmapAccess(0)

See Also

Effect Class | Effect Members