Android Camera实现毫秒级拍照实例

我们知道自定义Camera需要以下几步

1. 打开相机，即实例化Camera对象，Camera camera = Camera.open();
2. 设置Camera的相关参数，Camera.Parameters parameters = camera.getParameters();
3. 打开预览，camera.setPreviewDisplay(surfaceholder); camera.startPreview();
4. 获取图片，这里只是从预览中获取因此使用，camera.setPreviewCallback(new Camera.PreviewCallback(){……..});
5. 停止预览，释放相机，camera.stopPreview();camera.release();

1、打开相机

public static Camera openFacingBackCamera() {
    Camera cam = null;
    Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
    for (int camIdx = 0, cameraCount = Camera.getNumberOfCameras(); camIdx < cameraCount; camIdx++) {
      Camera.getCameraInfo(camIdx, cameraInfo);
      if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
 try {
   //打开相应的摄像头，目前是前置摄像头
   cam = Camera.open(camIdx);
 } catch (RuntimeException e) {
   e.printStackTrace();
   if (cam!=null){
     cam.stopPreview();
     cam.release();
   }
   cam = null;
 }
      }
    }
    return cam;
  }

2、设置相关参数和预览

//定义SurfaceView
private SurfaceView localSurface;
 // 为surfaceHolder添加一个回调监听器
    localSurface.getHolder().addCallback(new SurfaceHolder.Callback() {
      @Override
      public void surfaceCreated(SurfaceHolder holder) {

      }

      @Override
      public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
 camera = CameraUtil.openFacingBackCamera();
 //设置相机预览旋转角度
 camera.setDisplayOrientation(180);
 if (camera != null) {
   Camera.Parameters parameters = camera.getParameters();// 获得相机参数
   List sizes = parameters.getSupportedPreviewSizes();
   List sizes_pic = parameters.getSupportedPictureSizes();
   Camera.Size cs = sizes.get(0);
   int mWidth = cs.width;
   int mHeight = cs.height;
   parameters.setPreviewSize(mWidth, mHeight);
   parameters.setPictureSize(sizes_pic.get(0).width, sizes_pic.get(0).height);
   parameters.setJpegQuality(85);//
   parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
   parameters.setPictureFormat(ImageFormat.JPEG);
   camera.setParameters(parameters);
   try {
     camera.setPreviewDisplay(localSurface.getHolder());
     camera.startPreview(); // 开始预览
     camera.autoFocus(null); // 自动对焦
   } catch (IOException e) {
     e.printStackTrace();
     camera.stopPreview();
     camera.release();
     camera = null;
   }
 }
      }

      @Override
      public void surfaceDestroyed(SurfaceHolder holder) {
 if (camera!=null){
   camera.stopPreview();
   camera.release();
   camera = null;
 }
      }
    } );
    // 设置该SurfaceView自己不维护缓冲
    localSurface.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

3、获取图片

 private void getViewImage() {
   //设置监听
    camera.setPreviewCallback(new Camera.PreviewCallback(){

      @Override
      public void onPreviewframe(byte[] data, Camera camera) {
 Camera.Size size = camera.getParameters().getPreviewSize();
 try{
   YuvImage image = new YuvImage(data, ImageFormat.NV21, size.width, size.height, null);
   if(image!=null){
     ByteArrayOutputStream stream = new ByteArrayOutputStream();
     image.compressToJpeg(new Rect(0, 0, size.width, size.height), 80, stream);
     Bitmap bmp = BitmapFactory.decodeByteArray(stream.toByteArray(), 0, stream.size());
     //因为图片会放生旋转，因此要对图片进行旋转到和手机在一个方向上
     rotateBitmap(bmp);
     stream.close();
   }
 }catch(Exception ex){
   Log.e("Sys","Error:"+ex.getMessage());
 }
      }
    });
  }

旋转图片的方法

public void rotateMyBitmap(Bitmap bmp){
    Matrix matrix = new Matrix();
    matrix.postScale(-1, 1); // 镜像水平翻转(如果左右颠倒)
    matrix.postRotate(180);
    Bitmap nbmp = Bitmap.createBitmap(bmp, 0,0, bmp.getWidth(), bmp.getHeight(), matrix, true);
    imageView.setImageBitmap(nbmp);
  };

自定义时间拍照

  private Handler mHandler = new Handler() {
    public void handleMessage(Message msg) {
      switch (msg.what) {
 case 101:
   getViewImage();
   Log.e(TAG, "handleMessage: 拍照" );
   mHandler.sendEmptyMessageDelayed(102, 100);
   break;
 case 102:
   camera.setPreviewCallback(null);
   break ;
      }
    }
  };

然后点击按钮调用

mHandler.sendEmptyMessageDelayed(101, 100);

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。