how to convert bitmapsource to bitmap?

Question

how to convert bitmapsource to bitmap?

mc 6,056

I have gif and there is serveral images in it.

I want to get bitmap and I searched it but it is format of Format8Indexceed. which can not save or edit.

and I can not use SetPixel of the bitmap .

Answer accepted by question author

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Answer 1

Hi @mc ,

In WPF, BitmapSource and System.Drawing.Bitmap belong to two different imaging systems — WPF uses the System.Windows.Media.Imaging namespace, while GDI+ (System.Drawing) uses Bitmap. To convert between them, you’ll need to copy the pixel data manually or through an interop stream.

If your source is a BitmapSource (for example, a frame from a GifBitmapDecoder), you can write it into a memory stream using a BmpBitmapEncoder, then construct a System.Drawing.Bitmap from that stream:

using (var stream = new MemoryStream())
{
    var encoder = new BmpBitmapEncoder();
    encoder.Frames.Add(BitmapFrame.Create(bitmapSource));
    encoder.Save(stream);
 
    stream.Position = 0;
    using (var bitmap = new System.Drawing.Bitmap(stream))
    {
        // you can now use SetPixel, Save, etc.
    }
}

This approach preserves the image data in a standard bitmap format that GDI+ can understand, even if your original BitmapSource was in an indexed format like Format8bppIndexed.

If you’re dealing with frames from a GIF, WPF often decodes them as indexed bitmaps (Format8bppIndexed), which don’t support direct pixel editing in System.Drawing.Bitmap. The encoder approach above ensures the result is in a full-color format (e.g. 24-bit or 32-bit), making SetPixel and other drawing APIs usable.

You can check out the WPF Image Formats under WPF Imaging Overview for a good explanation of how BitmapSource, pixel formats, and encoding.

I hope this helps. Please reach out if you need any clarification.

Danny Nguyen (WICLOUD CORPORATION) 3,500 Reputation points Microsoft External Staff

2025-10-14T11:00:28.1133333+00:00

Hi there — just checking in as I haven’t heard back on this thread for a while.

If my answer worked out, feel free to mark the answer as accepted so others can benefit from it too. If you’re still running into issues or need help with indexed formats or pixel editing, I’m happy to assist further!

Answer 2

Starry Night 600

how to convert bitmapsource to bitmap?

For this, you can refer to the following code:

private System.Drawing.Bitmap BitmapFromSource(BitmapSource bitmapsource)
{
   System.Drawing.Bitmap bitmap;
   using (MemoryStream outStream = new MemoryStream())
  {
     BitmapEncoder enc = new BmpBitmapEncoder();
     enc.Frames.Add(BitmapFrame.Create(bitmapsource));
     enc.Save(outStream);
     bitmap = new System.Drawing.Bitmap(outStream);
 }
     return bitmap;
}

Answer 3

You can convert a BitmapSource to a System.Drawing.Bitmap using a MemoryStream or by copying pixel data. The simplest and most reliable way is via an encoder, such as BmpBitmapEncoder.

Example: Convert BitmapSource → Bitmap

using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Windows.Media.Imaging;

public static Bitmap BitmapFromSource(BitmapSource bitmapsource)
{
    using (MemoryStream stream = new MemoryStream())
    {
        BmpBitmapEncoder encoder = new BmpBitmapEncoder();
        encoder.Frames.Add(BitmapFrame.Create(bitmapsource));
        encoder.Save(stream);

        using (var tempBitmap = new Bitmap(stream))
        {
            return new Bitmap(tempBitmap);
        }
    }
}

Why This Works

BitmapSource (WPF) and Bitmap (GDI+) use different systems.

Using BmpBitmapEncoder converts the format into something Bitmap can load.

This avoids unsupported formats like Format8bppIndexed.

SetPixel Issue?

If you’re getting indexed format errors (8bppIndexed), this conversion gives you a 24bpp or 32bpp bitmap, so SetPixel will work afterward.

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how to convert bitmapsource to bitmap?

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