Converting BitmapImage to Bitmap and vice versa
C#.NetBitmapC# Problem Overview
I have BitmapImage in C#. I need to do operations on image. For example grayscaling, adding text on image, etc.
I have found function in stackoverflow for grayscaling which accepts Bitmap and returns Bitmap.
So I need to convert BitmapImage to Bitmap, do operation and convert back.
How can I do this? Is this best way?
C# Solutions
Solution 1 - C#
There is no need to use foreign libraries.
Convert a BitmapImage to Bitmap:
private Bitmap BitmapImage2Bitmap(BitmapImage bitmapImage)
{
// BitmapImage bitmapImage = new BitmapImage(new Uri("../Images/test.png", UriKind.Relative));
using(MemoryStream outStream = new MemoryStream())
{
BitmapEncoder enc = new BmpBitmapEncoder();
enc.Frames.Add(BitmapFrame.Create(bitmapImage));
enc.Save(outStream);
System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(outStream);
return new Bitmap(bitmap);
}
}
To convert the Bitmap back to a BitmapImage:
[System.Runtime.InteropServices.DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);
private BitmapImage Bitmap2BitmapImage(Bitmap bitmap)
{
IntPtr hBitmap = bitmap.GetHbitmap();
BitmapImage retval;
try
{
retval = (BitmapImage)Imaging.CreateBitmapSourceFromHBitmap(
hBitmap,
IntPtr.Zero,
Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
}
finally
{
DeleteObject(hBitmap);
}
return retval;
}
Solution 2 - C#
Here's an extension method for converting a Bitmap to BitmapImage.
public static BitmapImage ToBitmapImage(this Bitmap bitmap)
{
using (var memory = new MemoryStream())
{
bitmap.Save(memory, ImageFormat.Png);
memory.Position = 0;
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = memory;
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
bitmapImage.Freeze();
return bitmapImage;
}
}
Solution 3 - C#
If you just need to go from BitmapImage to Bitmap it's quite easy,
private Bitmap BitmapImage2Bitmap(BitmapImage bitmapImage)
{
return new Bitmap(bitmapImage.StreamSource);
}
Solution 4 - C#
using System.Windows.Interop; ...
private BitmapImage Bitmap2BitmapImage(Bitmap bitmap)
{
BitmapSource i = Imaging.CreateBitmapSourceFromHBitmap(
bitmap.GetHbitmap(),
IntPtr.Zero,
Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
return (BitmapImage)i;
}
Solution 5 - C#
I've just been trying to use the above in my code and I believe that there is a problem with the Bitmap2BitmapImage function (and possibly the other one as well).
using (MemoryStream ms = new MemoryStream())
Does the above line result in the stream being disposed of? Which means that the returned BitmapImage loses its content.
As I'm a WPF newbie I'm not sure that this is the correct technical explanation, but the code didn't work in my application until I removed the using directive.
Solution 6 - C#
Here the async version.
public static Task<BitmapSource> ToBitmapSourceAsync(this Bitmap bitmap)
{
return Task.Run(() =>
{
using (System.IO.MemoryStream memory = new System.IO.MemoryStream())
{
bitmap.Save(memory, ImageFormat.Png);
memory.Position = 0;
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = memory;
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
bitmapImage.Freeze();
return bitmapImage as BitmapSource;
}
});
}
Solution 7 - C#
Thanks Guillermo Hernandez, I created a variation of your code that works. I added the namespaces in this code for reference.
System.Reflection.Assembly theAsm = Assembly.LoadFrom("My.dll");
// Get a stream to the embedded resource
System.IO.Stream stream = theAsm.GetManifestResourceStream(@"picture.png");
// Here is the most important part:
System.Windows.Media.Imaging.BitmapImage bmi = new BitmapImage();
bmi.BeginInit();
bmi.StreamSource = stream;
bmi.EndInit();
Solution 8 - C#
This converts from System.Drawing.Bitmap to BitmapImage:
MemoryStream ms = new MemoryStream();
YOURBITMAP.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
BitmapImage image = new BitmapImage();
image.BeginInit();
ms.Seek(0, SeekOrigin.Begin);
image.StreamSource = ms;
image.EndInit();