I've found loads of people converting BitmapSources to Bitmaps, but what about ImageSources to Bitmaps? I am making an imaging program and I need to extract bitmaps from the image displayed in the Image element. Does anyone know how to do this?

EDIT 1:

This is a function for converting the Bitmap Image to a Bitmap. Remember to set the 'unsafe' option in the compiler preferences.

public static System.Drawing.Bitmap BitmapSourceToBitmap(BitmapSource srs)

{

System.Drawing.Bitmap btm = null;

int width = srs.PixelWidth;

int height = srs.PixelHeight;

int stride = width * ((srs.Format.BitsPerPixel + 7) / 8);

byte[] bits = new byte[height * stride];

srs.CopyPixels(bits, stride, 0);

unsafe

{

fixed (byte* pB = bits)

{

IntPtr ptr = new IntPtr(pB);

btm = new System.Drawing.Bitmap(width, height, stride, System.Drawing.Imaging.PixelFormat.Format1bppIndexed, ptr);

}

}

return btm;

}

Next is now to get a Bitmap Image:

RenderTargetBitmap targetBitmap = new RenderTargetBitmap(

(int)inkCanvas1.ActualWidth,

(int)inkCanvas1.ActualHeight,

96d, 96d,

PixelFormats.Default);

targetBitmap.Render(inkCanvas1);

MemoryStream mse = new MemoryStream();

System.Windows.Media.Imaging.BmpBitmapEncoder mem = new BmpBitmapEncoder();

mem.Frames.Add(BitmapFrame.Create(targetBitmap));

mem.Save(mse);

mse.Position = 0;

BitmapImage bi = new BitmapImage();

bi.BeginInit();

bi.StreamSource = mse;

bi.EndInit();

Next is to convert it:

Bitmap b = new Bitmap(BitmapSourceToBitmap(bi));

解决方案

Actually you don't need to use unsafe code. There's an overload of CopyPixels that accepts an IntPtr:

public static System.Drawing.Bitmap BitmapSourceToBitmap2(BitmapSource srs)

{

int width = srs.PixelWidth;

int height = srs.PixelHeight;

int stride = width * ((srs.Format.BitsPerPixel + 7) / 8);

IntPtr ptr = IntPtr.Zero;

try

{

ptr = Marshal.AllocHGlobal(height * stride);

srs.CopyPixels(new Int32Rect(0, 0, width, height), ptr, height * stride, stride);

using (var btm = new System.Drawing.Bitmap(width, height, stride, System.Drawing.Imaging.PixelFormat.Format1bppIndexed, ptr))

{

// Clone the bitmap so that we can dispose it and

// release the unmanaged memory at ptr

return new System.Drawing.Bitmap(btm);

}

}

finally

{

if (ptr != IntPtr.Zero)

Marshal.FreeHGlobal(ptr);

}

}