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Android:Camera2的简单使用

作者:互联网

以前用的是Camera,但是现在Camera已经被官方弃用了,所以这里使用的是Camera2进行演示

使用Camera需要注意的就是权限的获取,必须有权限

类图介绍

Camera2跟Camera1不一样,它使用了很多个类,每个类有自己的功能

这几个类是主要使用的,其他的比如   CameraCharacteristics   类用于获取跟摄像头有关的信息等等

 

代码实现

1、CameraManager获取系统摄像头

 1 CameraManager cameraManager = (CameraManager) this.getSystemService(Context.CAMERA_SERVICE); 

2、CameraManager打开指定摄像头,让Device进行操作

String cameraId = "" + CameraCharacteristics.LENS_FACING_FRONT;//得到后摄像头编号

        if (ActivityCompat.checkSelfPermission(context, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
            return;
        }

        CameraDevice.StateCallback deviceCallback = new CameraDevice.StateCallback() {
            @Override
            public void onOpened(@NonNull CameraDevice camera) {
                cameraDevice = camera;
            }
            @Override
            public void onDisconnected(@NonNull CameraDevice camera) {

            }
            @Override
            public void one rror(@NonNull CameraDevice camera, int error) {
               Log.e(TAG,"cameraManager打开摄像头失败");
            }
        };

        try {
            cameraManager.openCamera(cameraId, deviceCallback, null);
        } catch (CameraAccessException e) {
            Log.e(TAG,"cameraManager访问摄像头失败");
        }

3、使用CaptureRequest.Builder 指定配置信息和画面图片的传递

CaptureRequest.Builder previewRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            //将预览数据传递
            previewRequestBuilder.addTarget(imageReader.getSurface());
            previewRequestBuilder.addTarget(surfaceHolder.getSurface());

      // 自动对焦
            previewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
            // 打开闪光灯
            previewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);

 4、Device创建Session进行预览

cameraDevice.createCaptureSession(Arrays.asList(surfaceHolder.getSurface(), imageReader.getSurface()), new CameraCaptureSession.StateCallback() {
                @Override
                public void onConfigured(@NonNull CameraCaptureSession session) {

                    cameraCaptureSession = session;

                    CaptureRequest captureRequest = previewRequestBuilder.build();
                    try {
                        cameraCaptureSession.setRepeatingRequest(captureRequest,captureCallback,cameraHandler);

                    } catch (CameraAccessException e) {

                        Log.e(TAG,"cameraCaptureSession访问摄像头失败");
                    }
                }
                @Override
                public void onConfigureFailed(@NonNull CameraCaptureSession session) {

                }
            },null);

在参数中的surfaceHolder是当前画面的SurfaceView,imageReader是在下面进行定义的

5、使用imageReader对预览的图片进行操作

     final int MAX_PREVIEW_WIDTH = 1920;
        final int MAX_PREVIEW_HEIGHT = 1080;

        //imageReader通过将得到的图片存放在队列中,再取出来进行操作
        //队列满了就不再放入新的图片,设置图片队列大小为10
        imageReader = ImageReader.newInstance(MAX_PREVIEW_WIDTH,MAX_PREVIEW_HEIGHT, ImageFormat.JPEG,10);

        imageReader.setOnImageAvailableListener(reader -> {

            //取出最新的图片并清除队列里的旧图片
            Image image = reader.acquireLatestImage();
            //todo 对获取的图片进行操作

            //将图片转换成Bitmap
            ByteBuffer buffer = image.getPlanes()[0].getBuffer();
            byte[] bytes = new byte[buffer.remaining()];
            buffer.get(bytes);//由缓冲区存入字节数组

            final Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);

            //释放资源
            image.close();

        },cameraHandler);//由handler去执行这里面的代码

 

代码的地址:  https://gitee.com/chen_zhang_aw/android-camera2-test

标签:CameraDevice,Camera2,imageReader,void,简单,Android,CaptureRequest,previewRequestBu
来源: https://www.cnblogs.com/davidFB/p/15090897.html