Resize bitmap image

bitmap, c#, image, resize, wpf

Solution

Does your "surface" visual have scaling capability? You can wrap it in a Viewbox if not, then render the Viewbox at the size you want.

When you call Measure and Arrange on the surface, you should provide the size you want the bitmap to be.

To use the Viewbox, change your code to something like the following:

Viewbox viewbox = new Viewbox();
Size desiredSize = new Size(surface.Width / 2, surface.Height / 2);

viewbox.Child = surface;
viewbox.Measure(desiredSize);
viewbox.Arrange(new Rect(desiredSize));

RenderTargetBitmap renderBitmap =
    new RenderTargetBitmap(
    (int)desiredSize.Width,
    (int)desiredSize.Height, 96d, 96d,
    PixelFormats.Default);
renderBitmap.Render(viewbox);

Problem

I want to have smaller size at image saved. How can I resize it? I use this code for redering the image: ``` Size size = new Size(surface.Width, surface.Height); surface.Measure(size); surface.Arrange(new Rect(size)); // Create a render bitmap and push the surface to it RenderTargetBitmap renderBitmap = new RenderTargetBitmap( (int)size.Width, (int)size.Height, 96d, 96d, PixelFormats.Default); renderBitmap.Render(surface); BmpBitmapEncoder encoder = new BmpBitmapEncoder(); // push the rendered bitmap to it encoder.Frames.Add(BitmapFrame.Create(renderBitmap)); // save the data to the stream encoder.Save(outStream); ```

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