#IMAGE OPACITY VB.NET CODE#

#IMAGE OPACITY VB.NET CODE#

FastPix in my sig.) Taking advantage of Form Opacity offers the ultimate performance because it works directly through the graphics hardware - and the code can be very simple. You can speed it up considerably by using a LockBits based method to set the alpha bytes of the image (see e.g. That's where ClientSize comes in: it's the size excluding the borders.Īnother performance point is that ImageAttributes/ColorMatrix is by no means the fastest way of fading an image. You said you are matching your PictureBox sizes to the images, but does that mean a scale of 1:1? If the images are actually being scaled down, you can get better results by scaling them to the exact PictureBox size before use (e.g. Of course it depends in the first place on the size of the images and on the speed of you user's hardware. 800 * 600), but performance matters when you are doing anything with image transparency.

PictureBox1.Image = SetImageOpacity(newImage, opacityPercent)Įnd SubThis will work reasonably well on my computer for images of a moderate size (e.g. Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles Timer1.Tick PictureBox1.BackgroundImage = PictureBox1.Image To fade, set the newImage to its new value and call the FadeToNewImage sub: For a reasonably smooth fade, I step up the opacity not more than about 2-3% on each tick. I would use a timer (Timer1) set to a moderate speed say 30- 50 ms.

Rather than blending the images on a separate bitmap, I'll just copy the Image to the BackgroundImage of the PictureBox before starting the fade (with the corresponding scaling mode for both). G.DrawImage(sourceImage, New Rectangle(Point.Empty, bmp.Size), 0, 0, _īmp.Width, bmp.Height, GraphicsUnit.Pixel, ia)Įnd FunctionMaybe its already clear to you how you could use that to get the effect you want, but for completeness I'll offer a sketch of how I might use it.

Image opacity vb.net