与众不同 windows phone (22) - Device(设备)之摄像头(硬件快门, 自动对焦, 实时修改捕获视频).doc

介绍与众不同 windows phone 7.5 (sdk 7.1) 之设备 硬件快门 自动对焦、自动对焦到指定的点 实时修改捕获到的视频帧 示例1、演示如何响应硬件快门HardwareShutter.xaml HardwareShutter.xaml.cs/* * 演示如何捕获相机的硬件快门的相关事件 * * CameraButtons.ShutterKeyHalfPressed - 硬件快门半按压时所触发的事件 * CameraButtons.ShutterKeyPressed - 硬件快门全按压时所触发的事件 * CameraButtons.ShutterKeyReleased - 硬件快门被释放时所触发的事件 * * * 注：无论是拍照模式还是摄像模式，只有在摄像头工作起来的时候，系统才能响应硬件快门的相关事件 */using System;using System.Collections.Generic;using System.Linq;using System.Net;using System.Windows;using System.Windows.Controls;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation;using System.Windows.Shapes;using Microsoft.Phone.Controls; using Microsoft.Devices;using System.Windows.Navigation;namespace Demo.Device.Camera public partial class HardwareShutter : PhoneApplicationPage private PhotoCamera _camera; public HardwareShutter() InitializeComponent(); protected override void OnNavigatedTo(NavigationEventArgs e) if (PhotoCamera.IsCameraTypeSupported(CameraType.Primary) _camera = new PhotoCamera(CameraType.Primary); / 注册硬件快门的相关事件 CameraButtons.ShutterKeyHalfPressed += CameraButtons_ShutterKeyHalfPressed; CameraButtons.ShutterKeyPressed += CameraButtons_ShutterKeyPressed; CameraButtons.ShutterKeyReleased += CameraButtons_ShutterKeyReleased; / 相机模式下，必须将捕获到的信息输出到 UI 上，系统才能响应硬件快门的事件（同理，摄像模式下，必须调用了 CaptureSource.Start() 之后系统才能响应硬件快门的事件） videoBrush.SetSource(_camera); protected override void OnNavigatingFrom(NavigatingCancelEventArgs e) / 清理相关资源 CameraButtons.ShutterKeyHalfPressed -= CameraButtons_ShutterKeyHalfPressed; CameraButtons.ShutterKeyPressed -= CameraButtons_ShutterKeyPressed; CameraButtons.ShutterKeyReleased -= CameraButtons_ShutterKeyReleased; void CameraButtons_ShutterKeyHalfPressed(object sender, EventArgs e) lblMsg.Text = 快门半按压; void CameraButtons_ShutterKeyPressed(object sender, EventArgs e) lblMsg.Text = 快门全按压; void CameraButtons_ShutterKeyReleased(object sender, EventArgs e) lblMsg.Text = 快门被释放; 2、演示如何自动对焦，以及如何自动对焦到指定的点Focus.xaml Focus.xaml.cs/* * 演示如何自动对焦，以及如何自动对焦到指定的点 * * PhotoCamera - 用于提供相机功能 * Focus() - 让相机自动对焦 * FocusAtPoint(double x, double y) - 自动对焦到取景器上指定的点 * x, y - 取景器上需要对焦的点的坐标，取景器左上角坐标为 0,0，取景器右下角坐标为 1,1 * AutoFocusCompleted - 自动对焦完成后所触发的事件（事件参数为 CameraOperationCompletedEventArgs 类型） * * * CameraOperationCompletedEventArgs * Succeeded - 操作是否成功 * Exception - 异常信息 */using System;using System.Collections.Generic;using System.Linq;using System.Net;using System.Windows;using System.Windows.Controls;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation;using System.Windows.Shapes;using Microsoft.Phone.Controls;using Microsoft.Devices;using System.Windows.Navigation;namespace Demo.Device.Camera public partial class Focus : PhoneApplicationPage private PhotoCamera _camera; public Focus() InitializeComponent(); protected override void OnNavigatedTo(NavigationEventArgs e) if (PhotoCamera.IsCameraTypeSupported(CameraType.Primary) / 实例化 PhotoCamera，注册相关事件 _camera = new PhotoCamera(CameraType.Primary); _camera.AutoFocusCompleted += _camera_AutoFocusCompleted; / 在 VideoBrush 上显示摄像头捕获到的实时信息 videoBrush.SetSource(_camera); protected override void OnNavigatingFrom(NavigatingCancelEventArgs e) / 清理相关资源 _camera.AutoFocusCompleted -= _camera_AutoFocusCompleted; void _camera_AutoFocusCompleted(object sender, CameraOperationCompletedEventArgs e) if (e.Succeeded) Deployment.Current.Dispatcher.BeginInvoke(delegate() lblMsg.Text = 自动对焦完成; ); else Deployment.Current.Dispatcher.BeginInvoke(delegate() lblMsg.Text = 自动对焦失败; ); private void btnFocus_Click(object sender, RoutedEventArgs e) if (_camera.IsFocusSupported = true) try / 开始自动对焦 _camera.Focus(); lblMsg.Text = 开始自动对焦; catch (Exception ex) this.Dispatcher.BeginInvoke(delegate() lblMsg.Text = 自动对焦失败： + ex.ToString(); ); else this.Dispatcher.BeginInvoke(delegate() lblMsg.Text = 相机不支持自动对焦; ); private void canvas_Tap(object sender, System.Windows.Input.GestureEventArgs e) if (_camera != null) if (_camera.IsFocusAtPointSupported = true) try / 获取用户触摸的点相对于 canvas 的坐标 Point tapLocation = e.GetPosition(canvas); / 计算触摸点映射于取景器上的坐标（取景器左上角为0,0，右下角为1,1） double focusXPercent = tapLocation.X / canvas.Width; double focusYPercent = tapLocation.Y / canvas.Height; / 自动对焦到指定的点 _camera.FocusAtPoint(focusXPercent, focusYPercent); this.Dispatcher.BeginInvoke(delegate() lblMsg.Text = String.Format(自动对焦到指定的点0X：1:N22Y：3:N2, System.Environment.NewLine, focusXPercent, System.Environment.NewLine, focusYPercent); ); catch (Exception ex) this.Dispatcher.BeginInvoke(delegate() lblMsg.Text = 自动对焦到指定的点失败： + ex.ToString(); ); else this.Dispatcher.BeginInvoke(delegate() lblMsg.Text = 相机不支持自动对焦到指定的点; ); 3、演示如何实时修改捕获到的视频帧LiveAlter.xaml LiveAlter.xaml.cs/* * 演示如何实时处理摄像头捕获到的图像 * * PhotoCamera - 用于提供相机功能 * PreviewResolution - 捕获到的图像的当前的分辨率（返回 System.Windows.Size 类型的结构体，其包含 Width 和 Height 字段） * GetPreviewBufferArgb32(int pixelData) - 将当前捕获到的图像的 ARGB 数据复制到指定的缓冲区中 * * * 注： * Resolution 指的是相机设置的分辨率 * PreviewResolution 指的是系统针对显示设备缩放后的真实分辨率 * 因为通常相机能够拍摄大于设备显示器的分辨率的图像，所以实时显示摄像头捕获到的图像时，系统会对其分辨率进行优化，PreviewResolution 就是优化后的数据 */using System;using System.Collections.Generic;using System.Linq;using System.Net;using System.Windows;using System.Windows.Controls;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation;using System.Windows.Shapes;using Microsoft.Phone.Controls;using Microsoft.Devices;using System.Threading;using System.Windows.Media.Imaging;using System.Windows.Navigation;namespace Demo.Device.Camera public partial class LiveAlter : PhoneApplicationPage private PhotoCamera _camera = new PhotoCamera(); / 用于显示处理后的图像 private WriteableBitmap _writeableBitmap; / 有信号 private static ManualResetEvent _manualReset = new ManualResetEvent(true); public LiveAlter() InitializeComponent(); protected override void OnNavigatedTo(NavigationEventArgs e) if (PhotoCamera.IsCameraTypeSupported(CameraType.Primary) / 实例化 PhotoCamera，并注册相关事件 _camera = new PhotoCamera(CameraType.Primary); _camera.Initialized += _camera_Initialized; videoBrush.SetSource(_camera); else this.Dispatcher.BeginInvoke(delegate() lblMsg.Text = 设备不支持主摄像头; ); protected override void OnNavigatingFrom(NavigatingCancelEventArgs e) / 清理资源 if (_camera != null) _camera.Dispose(); _camera.Initialized -= _camera_Initialized; void _camera_Initialized(object sender, CameraOperationCompletedEventArgs e) / 新开线程去执行实时处理图片的任务 Thread thread = new Thread(CameraToGray); thread.Start(); this.Dispatcher.BeginInvoke(delegate() / 让 Image 显示 WriteableBitmap 中的内容 _writeableBitmap = new Writeab