Set background color in Bitmap Image
17,852
Solution 1
Try PixelFormats.Default
or PixelFormats.Bgra32
or PixelFormats.Rgb24
instead of PixelFormats.Pbgra32
.
The P stands for pre-multiplied - the assumption is that each channel is pre-multiplied by alpha.
Solution 2
Try this
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.Pbgra32);
DrawingVisual drawingVisual = new DrawingVisual();
using (DrawingContext drawingContext = drawingVisual.RenderOpen())
{
VisualBrush visualBrush = new VisualBrush(surface);
drawingContext.DrawRectangle(visualBrush, null,
new Rect(new Point(), new Size(size.Width, size.Height)));
}
renderBitmap.Render(drawingVisual);
// Create a file stream for saving image
using (FileStream outStream = new FileStream(filename, FileMode.Create))
{
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);
}
Author by
Ionică Bizău
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Updated on June 16, 2022Comments
-
Ionică Bizău almost 2 years
I want to save my canvas to image. It works but background color is black. How I must add to change the color?
I use this code:
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.Pbgra32); renderBitmap.Render(surface); // Create a file stream for saving image using (FileStream outStream = new FileStream(filename, FileMode.Create)) { 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); }