Android Camera2 拍照入門學(xué)習(xí)

2019-11-06 09:42:34

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學(xué)習(xí)資料：

腎虛將軍android camera2 詳解說明極客學(xué)院android.hardware.camera2 使用指南

Android 5.0(21)之后，android.hardware.Camera被廢棄(下面稱為Camera1)，還有一個(gè)android.graphics.Camera，這個(gè)android.graphics.Camera不是用來照相的，是用來處理圖像的，可以做出3D的圖像效果之類的，之前的Camera1則由android.hardware.Camera2來代替

Camera2支持RAW輸出，可以調(diào)節(jié)曝光，對(duì)焦模式，快門等，功能比原先Camera強(qiáng)大

1.Camera1使用

使用步驟：

調(diào)用Camera.open()，打開相機(jī)，默認(rèn)為后置，可以根據(jù)攝像頭ID來指定打開前置還是后置調(diào)用Camera.getParameters()得到一個(gè)Camera.Parameters對(duì)象使用步驟2得到的Camera.Parameters對(duì)象，對(duì)拍照參數(shù)進(jìn)行設(shè)置調(diào)用Camera.setPReviewDispaly(SurfaceHolder holder)，指定使用哪個(gè)SurfaceView來顯示預(yù)覽圖片調(diào)用Camera.startPreview()方法開始預(yù)覽取景調(diào)用Camera.takePicture()方法進(jìn)行拍照拍照結(jié)束后，調(diào)用Camera.stopPreview()結(jié)束取景預(yù)覽，之后再replease()方法釋放資源

這幾個(gè)步驟從瘋狂Android講義中學(xué)到

1.1簡(jiǎn)單使用

效果

使用SurfaceView進(jìn)行取景的預(yù)覽，點(diǎn)擊屏幕進(jìn)行拍照，用ImageView來展示拍的照片

取景

拍照預(yù)覽

想買關(guān)于操作系統(tǒng)和C的書看，知乎很多人推薦這兩本，就買了，感覺確實(shí)不錯(cuò)。然而，深入理解操作系統(tǒng)買早了，啃不動(dòng)

布局文件：

Activity代碼：

public class CameraActivity extends AppCompatActivity implements View.OnClickListener { private SurfaceView mSurfaceView; private SurfaceHolder mSurfaceHolder; private Camera mCamera; private ImageView iv_show; private int viewWidth, viewHeight;//mSurfaceView的寬和高 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_camera2); initView(); } /** * 初始化控件 */ private void initView() { iv_show = (ImageView) findViewById(R.id.iv_show_camera2_activity); //mSurfaceView mSurfaceView = (SurfaceView) findViewById(R.id.surface_view_camera2_activity); mSurfaceHolder = mSurfaceView.getHolder(); // mSurfaceView 不需要自己的緩沖區(qū) mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); // mSurfaceView添加回調(diào) mSurfaceHolder.addCallback(new SurfaceHolder.Callback() { @Override public void surfaceCreated(SurfaceHolder holder) { //SurfaceView創(chuàng)建 // 初始化Camera initCamera(); } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } @Override public void surfaceDestroyed(SurfaceHolder holder) { //SurfaceView銷毀 // 釋放Camera資源 if (mCamera != null) { mCamera.stopPreview(); mCamera.release(); } } }); //設(shè)置點(diǎn)擊監(jiān)聽 mSurfaceView.setOnClickListener(this); } @Override public void onWindowFocusChanged(boolean hasFocus) { super.onWindowFocusChanged(hasFocus); if (mSurfaceView != null) { viewWidth = mSurfaceView.getWidth(); viewHeight = mSurfaceView.getHeight(); } } /** * SurfaceHolder 回調(diào)接口方法 */ private void initCamera() { mCamera = Camera.open();//默認(rèn)開啟后置 mCamera.setDisplayOrientation(90);//攝像頭進(jìn)行旋轉(zhuǎn)90° if (mCamera != null) { try { Camera.Parameters parameters = mCamera.getParameters(); //設(shè)置預(yù)覽照片的大小 parameters.setPreviewFpsRange(viewWidth, viewHeight); //設(shè)置相機(jī)預(yù)覽照片幀數(shù) parameters.setPreviewFpsRange(4, 10); //設(shè)置圖片格式 parameters.setPictureFormat(ImageFormat.JPEG); //設(shè)置圖片的質(zhì)量 parameters.set("jpeg-quality", 90); //設(shè)置照片的大小 parameters.setPictureSize(viewWidth, viewHeight); //通過SurfaceView顯示預(yù)覽 mCamera.setPreviewDisplay(mSurfaceHolder); //開始預(yù)覽 mCamera.startPreview(); } catch (IOException e) { e.printStackTrace(); } } } /** * 點(diǎn)擊回調(diào)方法 */ @Override public void onClick(View v) { if (mCamera == null) return; //自動(dòng)對(duì)焦后拍照 mCamera.autoFocus(autoFocusCallback); } /** * 自動(dòng)對(duì)焦對(duì)焦成功后就進(jìn)行拍照 */ Camera.AutoFocusCallback autoFocusCallback = new Camera.AutoFocusCallback() { @Override public void onAutoFocus(boolean success, Camera camera) { if (success) {//對(duì)焦成功 camera.takePicture(new Camera.ShutterCallback() {//按下快門 @Override public void onShutter() { //按下快門瞬間的操作 } }, new Camera.PictureCallback() { @Override public void onPictureTaken(byte[] data, Camera camera) {//是否保存原始圖片的信息 } }, pictureCallback); } } }; /** * 獲取圖片 */ Camera.PictureCallback pictureCallback = new Camera.PictureCallback() { @Override public void onPictureTaken(byte[] data, Camera camera) { final Bitmap resource = BitmapFactory.decodeByteArray(data, 0, data.length); if (resource == null) { Toast.makeText(CameraActivity.this, "拍照失敗", Toast.LENGTH_SHORT).show(); } final Matrix matrix = new Matrix(); matrix.setRotate(90); final Bitmap bitmap = Bitmap.createBitmap(resource, 0, 0, resource.getWidth(), resource.getHeight(), matrix, true); if (bitmap != null && iv_show != null && iv_show.getVisibility() == View.GONE) { mCamera.stopPreview(); iv_show.setVisibility(View.VISIBLE); mSurfaceView.setVisibility(View.GONE); Toast.makeText(CameraActivity.this, "拍照", Toast.LENGTH_SHORT).show(); iv_show.setImageBitmap(bitmap); } } };}

權(quán)限：

<uses-permission android:name="android.permission.CAMERA" />

在獲得圖片后，想要顯示的效果是照片是豎直顯示，resource顯示的卻是逆時(shí)針旋轉(zhuǎn)了90°，照片是橫著的，就使用matrix.setRotate(90)進(jìn)行旋轉(zhuǎn)

2.Camera2

Camera2拍照示意圖

這里引用了管道的概念將安卓設(shè)備和攝像頭之間聯(lián)通起來，系統(tǒng)向攝像頭發(fā)送 Capture 請(qǐng)求，而攝像頭會(huì)返回 CameraMetadata。這一切建立在一個(gè)叫作 CameraCapturesession 的會(huì)話中。

camera2中主要的類

以上從極客學(xué)院android.hardware.camera2 使用指南摘抄

CameraManaer 攝像頭管理器，用于檢測(cè)攝像頭，打開系統(tǒng)攝像頭，調(diào)用CameraManager.getCameraCharacteristics(String)可以獲取指定攝像頭的相關(guān)特性CameraCharacteristics 攝像頭的特性CameraDevice 攝像頭，類似android.hardware.Camera也就是Camera1的CameraCameraCaptureSession 這個(gè)對(duì)象控制攝像頭的預(yù)覽或者拍照，setRepeatingRequest()開啟預(yù)覽，capture()拍照，CameraCaptureSession提供了StateCallback、CaptureCallback兩個(gè)接口來監(jiān)聽CameraCaptureSession的創(chuàng)建和拍照過程。CameraRequest和CameraRequest.Builder，預(yù)覽或者拍照時(shí)，都需要一個(gè)CameraRequest對(duì)象。CameraRequest表示一次捕獲請(qǐng)求，用來對(duì)z照片的各種參數(shù)設(shè)置，比如對(duì)焦模式、曝光模式等。CameraRequest.Builder用來生成CameraRequest對(duì)象。

以上從腎虛將軍的android camera2 詳解說明摘抄

2.1 簡(jiǎn)單使用

使用的依然是SurfaceView來進(jìn)行展示預(yù)覽

主要思路：

獲得攝像頭管理器CameraManager mCameraManager，mCameraManager.openCamera()來打開攝像頭指定要打開的攝像頭，并創(chuàng)建openCamera()所需要的CameraDevice.StateCallback stateCallback在CameraDevice.StateCallback stateCallback中調(diào)用takePreview()，這個(gè)方法中，使用CaptureRequest.Builder創(chuàng)建預(yù)覽需要的CameraRequest，并初始化了CameraCaptureSession，最后調(diào)用了setRepeatingRequest(previewRequest, null, childHandler)進(jìn)行了預(yù)覽點(diǎn)擊屏幕，調(diào)用takePicture()，這個(gè)方法內(nèi)，最終調(diào)用了capture(mCaptureRequest, null, childHandler)在new ImageReader.OnImageAvailableListener(){}回調(diào)方法中，將拍照拿到的圖片進(jìn)行展示

代碼：

public class Camera2Activity extends AppCompatActivity implements View.OnClickListener { private static final SparseIntArray ORIENTATIONS = new SparseIntArray(); ///為了使照片豎直顯示 static { ORIENTATIONS.append(Surface.ROTATION_0, 90); ORIENTATIONS.append(Surface.ROTATION_90, 0); ORIENTATIONS.append(Surface.ROTATION_180, 270); ORIENTATIONS.append(Surface.ROTATION_270, 180); } private SurfaceView mSurfaceView; private SurfaceHolder mSurfaceHolder; private ImageView iv_show; private CameraManager mCameraManager;//攝像頭管理器 private Handler childHandler, mainHandler; private String mCameraID;//攝像頭Id 0 為后 1 為前 private ImageReader mImageReader; private CameraCaptureSession mCameraCaptureSession; private CameraDevice mCameraDevice; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_camera2); initVIew(); } /** * 初始化 */ private void initVIew() { iv_show = (ImageView) findViewById(R.id.iv_show_camera2_activity); //mSurfaceView mSurfaceView = (SurfaceView) findViewById(R.id.surface_view_camera2_activity); mSurfaceView.setOnClickListener(this); mSurfaceHolder = mSurfaceView.getHolder(); mSurfaceHolder.setKeepScreenOn(true); // mSurfaceView添加回調(diào) mSurfaceHolder.addCallback(new SurfaceHolder.Callback() { @Override public void surfaceCreated(SurfaceHolder holder) { //SurfaceView創(chuàng)建 // 初始化Camera initCamera2(); } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } @Override public void surfaceDestroyed(SurfaceHolder holder) { //SurfaceView銷毀 // 釋放Camera資源 if (null != mCameraDevice) { mCameraDevice.close(); Camera2Activity.this.mCameraDevice = null; } } }); } /** * 初始化Camera2 */ @RequiresApi(api = Build.VERSION_CODES.LOLLipOP) private void initCamera2() { HandlerThread handlerThread = new HandlerThread("Camera2"); handlerThread.start(); childHandler = new Handler(handlerThread.getLooper()); mainHandler = new Handler(getMainLooper()); mCameraID = "" + CameraCharacteristics.LENS_FACING_FRONT;//后攝像頭 mImageReader = ImageReader.newInstance(1080, 1920, ImageFormat.JPEG,1); mImageReader.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() { //可以在這里處理拍照得到的臨時(shí)照片例如，寫入本地 @Override public void onImageAvailable(ImageReader reader) { mCameraDevice.close(); mSurfaceView.setVisibility(View.GONE); iv_show.setVisibility(View.VISIBLE); // 拿到拍照照片數(shù)據(jù) Image image = reader.acquireNextImage(); ByteBuffer buffer = image.getPlanes()[0].getBuffer(); byte[] bytes = new byte[buffer.remaining()]; buffer.get(bytes);//由緩沖區(qū)存入字節(jié)數(shù)組 final Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length); if (bitmap != null) { iv_show.setImageBitmap(bitmap); } } }, mainHandler); //獲取攝像頭管理 mCameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE); try { if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) { return; } //打開攝像頭 mCameraManager.openCamera(mCameraID, stateCallback, mainHandler); } catch (Camera accessException e) { e.printStackTrace(); } } /** * 攝像頭創(chuàng)建監(jiān)聽 */ private CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() { @Override public void onOpened(CameraDevice camera) {//打開攝像頭 mCameraDevice = camera; //開啟預(yù)覽 takePreview(); } @Override public void onDisconnected(CameraDevice camera) {//關(guān)閉攝像頭 if (null != mCameraDevice) { mCameraDevice.close(); Camera2Activity.this.mCameraDevice = null; } } @Override public void onError(CameraDevice camera, int error) {//發(fā)生錯(cuò)誤 Toast.makeText(Camera2Activity.this, "攝像頭開啟失敗", Toast.LENGTH_SHORT).show(); } }; /** * 開始預(yù)覽 */ private void takePreview() { try { // 創(chuàng)建預(yù)覽需要的CaptureRequest.Builder final CaptureRequest.Builder previewRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW); // 將SurfaceView的surface作為CaptureRequest.Builder的目標(biāo) previewRequestBuilder.addTarget(mSurfaceHolder.getSurface()); // 創(chuàng)建CameraCaptureSession，該對(duì)象負(fù)責(zé)管理處理預(yù)覽請(qǐng)求和拍照請(qǐng)求 mCameraDevice.createCaptureSession(Arrays.asList(mSurfaceHolder.getSurface(), mImageReader.getSurface()), new CameraCaptureSession.StateCallback() // ③ { @Override public void onConfigured(CameraCaptureSession cameraCaptureSession) { if (null == mCameraDevice) return; // 當(dāng)攝像頭已經(jīng)準(zhǔn)備好時(shí)，開始顯示預(yù)覽 mCameraCaptureSession = cameraCaptureSession; try { // 自動(dòng)對(duì)焦 previewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE); // 打開閃光燈 previewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_AUTO_Flash); // 顯示預(yù)覽 CaptureRequest previewRequest = previewRequestBuilder.build(); mCameraCaptureSession.setRepeatingRequest(previewRequest, null, childHandler); } catch (CameraAccessException e) { e.printStackTrace(); } } @Override public void onConfigureFailed(CameraCaptureSession cameraCaptureSession) { Toast.makeText(Camera2Activity.this, "配置失敗", Toast.LENGTH_SHORT).show(); } }, childHandler); } catch (CameraAccessException e) { e.printStackTrace(); } } /** * 點(diǎn)擊事件 */ @Override public void onClick(View v) { takePicture(); } /** * 拍照 */ private void takePicture() { if (mCameraDevice == null) return; // 創(chuàng)建拍照需要的CaptureRequest.Builder final CaptureRequest.Builder captureRequestBuilder; try { captureRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE); // 將imageReader的surface作為CaptureRequest.Builder的目標(biāo) captureRequestBuilder.addTarget(mImageReader.getSurface()); // 自動(dòng)對(duì)焦 captureRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE); // 自動(dòng)曝光 captureRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH); // 獲取手機(jī)方向 int rotation = getWindowManager().getDefaultDisplay().getRotation(); // 根據(jù)設(shè)備方向計(jì)算設(shè)置照片的方向 captureRequestBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation)); //拍照 CaptureRequest mCaptureRequest = captureRequestBuilder.build(); mCameraCaptureSession.capture(mCaptureRequest, null, childHandler); } catch (CameraAccessException e) { e.printStackTrace(); } }}

布局代碼以及權(quán)限與Camera1中一樣，效果一樣

預(yù)覽時(shí)，是將mSurfaceHolder.getSurface()作為目標(biāo)顯示拍照結(jié)果時(shí)，是將mImageReader.getSurface()作為目標(biāo)