C# WPF 显示图片和视频显示 EmuguCv、AForge.Net测试

WPF 没有用到 PictureBox, 而是用Image代替.

下面我试着加载显示一个图片 。

XAML

<Image x:Name="srcImg"Width="400"Height="300"></Image>

CS Attempt 1:

Image<Bgr,Byte>My_Image=newImage<Bgr,byte>(Openfile.FileName);
srcImg.Source=My_Image.ToBitmap();

Error Message

Cannot implicitly convert type 'System.Drawing.Bitmap'
to 'System.Windows.Media.ImageSource'

CS Attempt 2:

Image<Bgr,Byte>My_Image=newImage<Bgr,byte>(Openfile.FileName);
srcImg.Source=newBitmapImage(My_Image);

Error Message

Error1The best overloaded method match for'System.Windows.Media.Imaging.BitmapImage.BitmapImage(System.Uri)' has some invalid arguments
Error2Argument1: cannot convert from'Emgu.CV.Image<Emgu.CV.Structure.Bgr,byte>' to 'System.Uri'

解决方法：

Image<Bgr, Byte> My_Image = new Image<Bgr, byte>(Openfile.FileName);
srcImg.Source = BitmapSourceConvert.ToBitmapSource(myImage);

public static class BitmapSourceConvert
{
    [DllImport("gdi32")]
    private static extern int DeleteObject(IntPtr o);

    public static BitmapSource ToBitmapSource(IImage image)
    {
        using (System.Drawing.Bitmap source = image.Bitmap)
        {
            IntPtr ptr = source.GetHbitmap();

            BitmapSource bs = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
                ptr,
                IntPtr.Zero,
                Int32Rect.Empty,
                System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());

            DeleteObject(ptr);
            return bs;
        }
    }
}

测试：

 Bitmap bm = (Bitmap)Bitmap.FromFile(@"D:\my_testfiles\Main.png");
            int count = ;
            for (int i = ; i < count; i++)
            {
                Commons.BitMapToImageSource(bm.Clone() as Bitmap);

            }

结果：

当循环 1527次，  耗时 00:00:17.8860231后  报错。

ErrorTrace：

 at System.Drawing.Bitmap.GetHbitmap(Color background)
   at System.Drawing.Bitmap.GetHbitmap()
   at SimpleClient.Commons.BitMapToImageSource(Bitmap bitmap) in D:\my_svn\universal-project\SimpleClient\Program.cs:line 

ErrorMessage:

system.OutOfMemoryException: Out of memory.

改进：

写一个视频显示控件，内部实现显示Bitmap转换成BitmapSource。为控件Source开辟一块内存控件，然后一直刷新。首先我们使用EmuguCV里面的Capture。
控件继承Image、IDisposable接口并开放一个属性VideoSource。

代码如下：

    public class CapPlayer : Image, IDisposable
    {
        private Capture videoSource;
        public Capture VideoSource
        {
            set
            {
                if (value != null)
                {
                    this.videoSource = value;
                    this.LaodCapPlayer();
                }
            }
        }

        private InteropBitmap bitmapSource;
        private IntPtr map;
        private IntPtr section;

        public CapPlayer()
        {
            Application.Current.Exit += new ExitEventHandler(Current_Exit);
        }

        private void LaodCapPlayer()
        {
            videoSource.ImageGrabbed += new Capture.GrabEventHandler(videoSource_ImageGrabbed);
            videoSource.Start();

            uint pcount = (uint)(videoSource.Width * videoSource.Height * PixelFormats.Bgr32.BitsPerPixel / );
            section = CreateFileMapping(new IntPtr(-), IntPtr.Zero, 0x04, , pcount, null);
            map = MapViewOfFile(section, 0xF001F, , , pcount);
            bitmapSource = Imaging.CreateBitmapSourceFromMemorySection(section, (int)videoSource.Width, (int)videoSource.Height, PixelFormats.Bgr32,
                (int)(videoSource.Width * PixelFormats.Bgr32.BitsPerPixel / ), ) as InteropBitmap;
            this.Source = bitmapSource;
        }

        void videoSource_ImageGrabbed(object sender, EventArgs e)
        {
            Capture camera = sender as Capture;
            var frame = camera.RetrieveBgrFrame().Bitmap;
            if (this.Dispatcher != null)
            {
                this.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Render, (SendOrPostCallback)delegate
                {
                    if (map != IntPtr.Zero)
                    {
                        try
                        {
                            System.Drawing.Imaging.BitmapData bmpData = frame.LockBits(new System.Drawing.Rectangle(, , (int)videoSource.Width, (int)videoSource.Height),
                            System.Drawing.Imaging.ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format32bppRgb);
                            /* Get the pointer to the pixels */
                            IntPtr pBmp = bmpData.Scan0;
                            int srcStride = bmpData.Stride;
                            int pSize = srcStride * (int)videoSource.Height;
                            CopyMemory(map, pBmp, pSize);
                            frame.UnlockBits(bmpData);
                        }
                        catch (Exception ex)
                        {
                            Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write(ex, "Info", );
                        }

                    }

                    if (bitmapSource != null)
                    {
                        bitmapSource.Invalidate();
                    }
                }, null);

            }

            if (captureLock)
            {
                try
                {
                    lock (mutCurrentImg)
                    {
                        camera.RetrieveBgrFrame().Save(imageFileName);
                    }
                }
                catch (System.Exception ex)
                {
                    Microsoft.Practices.EnterpriseLibrary.Logging.Logger.Write(ex, "Info", );
                }
                captureLock = false;
            }
        }

        void Current_Exit(object sender, ExitEventArgs e)
        {
            this.Dispose();
        }
        object mutCurrentImg = new object();
        bool captureLock = false;
        string imageFileName = string.Empty;
        public void ImaggingCapture(string imageFileName)
        {
            this.imageFileName = imageFileName;
            this.captureLock = true;
        }

        #region IDisposable Members

        public void Dispose()
        {
            if (videoSource != null)
                videoSource.Stop();
            Application.Current.Exit -= new ExitEventHandler(Current_Exit);
        }

        #endregion

        [DllImport("Kernel32.dll", EntryPoint = "RtlMoveMemory")]
        private static extern void CopyMemory(IntPtr Destination, IntPtr Source, int Length);

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern IntPtr CreateFileMapping(IntPtr hFile, IntPtr lpFileMappingAttributes, uint flProtect, uint dwMaximumSizeHigh, uint dwMaximumSizeLow, string lpName);

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern IntPtr MapViewOfFile(IntPtr hFileMappingObject, uint dwDesiredAccess, uint dwFileOffsetHigh, uint dwFileOffsetLow, uint dwNumberOfBytesToMap);

    }

测试结果：无异常，但是发现比较占用CPU 10%左右，内存 122M 左右，线程数32.

感觉不太理想CPU占用太多，我们把EmuguCV的Capture改为AForge.NEt的VideoCaptureDevice，代码如下：

    public class CapPlayer : Image, IDisposable
    {
        private  VideoCaptureDevice videoSource;
        private InteropBitmap bitmapSource;
        private IntPtr map;
        private IntPtr section;

        public CapPlayer()
        {

            Application.Current.Exit += new ExitEventHandler(Current_Exit);
            this.Loaded += new RoutedEventHandler(CapPlayer_Loaded);
            videoSource = new VideoCaptureDevice(@"device:pnp:\\?\usb#vid_0ac8&pid_305b#5&ee85354&0&2#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\global");  

        }

        void CapPlayer_Loaded(object sender, RoutedEventArgs e)
        {
            videoSource.NewFrame += new NewFrameEventHandler(videoSource_NewFrame);
            videoSource.Start();

            uint pcount = (uint)(this.Width * this.Height * PixelFormats.Bgr32.BitsPerPixel / );
            section = CreateFileMapping(new IntPtr(-), IntPtr.Zero, 0x04, , pcount, null);
            map = MapViewOfFile(section, 0xF001F, , , pcount);
            bitmapSource = System.Windows.Interop.Imaging.CreateBitmapSourceFromMemorySection(section, (int)this.Width, (int)this.Height, PixelFormats.Bgr32,
                (int)(this.Width * PixelFormats.Bgr32.BitsPerPixel / ), ) as InteropBitmap;
            this.Source = bitmapSource;
        }

        void Current_Exit(object sender, ExitEventArgs e)
        {
            this.Dispose();
        }
        object mutCurrentImg = new object();
        bool captureLock = false;
        string imageFileName = string.Empty;
        public void ImaggingCapture(string imageFileName)
        {
            this.imageFileName = imageFileName;
            this.captureLock = true;
        }

        private void videoSource_NewFrame(object sender, NewFrameEventArgs eventArgs)
        {
            //eventArgs.Frame.Save(stream, System.Drawing.Imaging.ImageFormat.Bmp);

            if (this.Dispatcher != null)
            {
                this.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Render, (SendOrPostCallback)delegate
                {
                    if (map != IntPtr.Zero)
                    {
                        System.Drawing.Imaging.BitmapData bmpData = eventArgs.Frame.LockBits(new System.Drawing.Rectangle(, , (int)this.Width, (int)this.Height),
                        System.Drawing.Imaging.ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format32bppRgb);
                        /* Get the pointer to the pixels */
                        IntPtr pBmp = bmpData.Scan0;
                        int srcStride = bmpData.Stride;
                        int pSize = srcStride * (int)this.Height;
                        CopyMemory(map, pBmp, pSize);
                        eventArgs.Frame.UnlockBits(bmpData);
                    }

                    if (bitmapSource != null)
                    {
                        bitmapSource.Invalidate();
                    }
                }, null);

            }

            if (captureLock)
            {
                try
                {
                    lock (mutCurrentImg)
                    {
                        eventArgs.Frame.Save(imageFileName);
                    }
                }
                catch (System.Exception ex)
                {
                }
                captureLock = false;
            }
        }

        #region IDisposable Members

        public void Dispose()
        {
            if (videoSource != null)
                videoSource.SignalToStop();
        }

        #endregion

        [DllImport("Kernel32.dll", EntryPoint = "RtlMoveMemory")]
        private static extern void CopyMemory(IntPtr Destination, IntPtr Source, int Length);

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern IntPtr CreateFileMapping(IntPtr hFile, IntPtr lpFileMappingAttributes, uint flProtect, uint dwMaximumSizeHigh, uint dwMaximumSizeLow, string lpName);

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern IntPtr MapViewOfFile(IntPtr hFileMappingObject, uint dwDesiredAccess, uint dwFileOffsetHigh, uint dwFileOffsetLow, uint dwNumberOfBytesToMap);

    }

测试结果：无异常，但是发现占用CPU 1%左右，内存 72M 左右，线程数28. 是不是比较理想呢！！

	CPU	内存	线程数
EmuguCV	10%左右	122M左右	32
Aforge.Net	1%左右	72M左右	28

我的电脑配置.

摄像头：FrameRate 30，Width 320 Height 240.

电脑型号 戴尔 Precision WorkStation T3400 Tower
操作系统 Windows 7 旗舰版 32位 SP1 ( DirectX 11 )
处理器 英特尔 酷睿2 双核 E8400 @ 3.00GHz
主板 戴尔 0HY553 (英特尔 X38/X48 Express 芯片组 - ICH9R)
内存 4 GB ( 海力士 DDR2 800MHz / 金士顿 DDR2 667MHz )
主硬盘 西数 WDC WD3200AAKS-75L9A0 ( 320 GB / 7200 转/分 )
显卡 Nvidia Quadro NVS 290 ( 256 MB / Nvidia )
显示器 戴尔 DELA04A DELL E170S ( 17.1 英寸 )
光驱 飞利浦-建兴 DVD-ROM DH-16D5S DVD光驱
声卡 Analog Devices AD1984 @ 英特尔 82801I(ICH9) 高保真音频
网卡 博通 BCM5754 NetXtreme Gigabit Ethernet / 戴尔

gdi32.dll

系统文件gdi32.dll是存放在Windows系统文件夹中的重要文件，通常情况下是在安装操作系统过程中自动创建的，对于系统正常运行来说至关重要。除非用户电脑被木马病毒、或是流氓软件篡改导致出现gdi32.dll丢失、缺失损坏等弹窗现象，否则不建议用户对该类文件（gdi32.dll）进行随意的修改。

gdi32.dll是Windows GDI图形用户界面相关程序，包含的函数用来绘制图像和显示文字。