How to display quick-updating images without large memory allocation?

If you are using the lastest WPF bits check out WriteableBitmap, you'll have to do more of the leg work but you'll really fast updates.

Do a quick google and you'll get some samples.

Here's some code I wrote* for aliasing (sharing memory) between a WPF BitmapSource and a GDI Bitmap (for my own project)

Obviously, you'll need to tweak it for your own needs, it'll probably end up with a less "hacky" feel in the end.

class AliasedBitmapSource : BitmapSource {    private Bitmap source;    public AliasedBitmapSource(Bitmap source) {        this.source = source;        this.pixelHeight = source.Height;        this.pixelWidth = source.Width;        this.dpiX = source.HorizontalResolution;        this.dpiY = source.VerticalResolution;    }    public override event EventHandler DownloadCompleted;    public override event EventHandler<ExceptionEventArgs> DownloadFailed;    public override event EventHandler<ExceptionEventArgs> DecodeFailed;    protected override Freezable CreateInstanceCore() {        throw new NotImplementedException();    }    private readonly double dpiX;    public override double DpiX {        get {            return dpiX;        }    }    private readonly double dpiY;    public override double DpiY {        get {            return dpiY;        }    }    private readonly int pixelHeight;    public override int PixelHeight {        get {            return pixelHeight;        }    }    private readonly int pixelWidth;    public override int PixelWidth {        get {            return pixelWidth;        }    }    public override System.Windows.Media.PixelFormat Format {        get {            return PixelFormats.Bgra32;        }    }    public override BitmapPalette Palette {        get {            return null;        }    }    public unsafe override void CopyPixels(Int32Rect sourceRect, Array pixels, int stride, int offset) {        BitmapData sourceData = source.LockBits(        sourceRect.ToRectangle(),        ImageLockMode.ReadWrite,        System.Drawing.Imaging.PixelFormat.Format32bppArgb);        fixed (byte* _ptr = &((byte[])pixels)[0]) {            byte* dstptr = _ptr;            byte* srcptr = (byte*)sourceData.Scan0;            for (int i = 0; i < pixels.Length; ++i) {                *dstptr = *srcptr;                ++dstptr;                ++srcptr;            }        }        source.UnlockBits(sourceData);    }}public static class Extensions {    public static Rectangle ToRectangle(this Int32Rect me) {        return new Rectangle(        me.X,        me.Y,        me.Width,        me.Height);    }    public static Int32Rect ToInt32Rect(this Rectangle me) {        return new Int32Rect(        me.X,        me.Y,        me.Width,        me.Height);    }}

*by "wrote" I mean "threw together in 10 minutes"