implement zoom in Camera2 api. [closed]

I am new to android and working on android camera2 api. I am unable to implement zoom in Camera2 api. I am making a magnifier app. Do I need to change the settings to Macro modeor Auto focus will do that for me? I want to implement zoom using ZoomContols. Please help. Thanks. I have attached my code snippet. please tell me how to implement it.
package com.lamaan.magmicrocam;

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.Camera;
import android.graphics.ImageFormat;
import android.graphics.Rect;
import android.graphics.SurfaceTexture;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraCaptureSession;
import android.hardware.camera2.CameraCharacteristics;
import android.hardware.camera2.CameraDevice;  
import android.hardware.camera2.CameraManager;
import android.hardware.camera2.CameraMetadata;
import android.hardware.camera2.CaptureRequest;
import android.hardware.camera2.TotalCaptureResult;
import android.hardware.camera2.params.StreamConfigurationMap;
import android.media.Image;
import android.media.ImageReader;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.HandlerThread;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.FloatMath;
import android.util.Log;
import android.util.Size;
import android.util.SparseIntArray;
import android.view.MotionEvent;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.TextureView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.widget.ZoomControls;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.security.Policy;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class MagnifierActivity extends AppCompatActivity {

    private Camera camera;
    private android.hardware.Camera.Parameters params;

    float finger_spacing = 0;
    float zoom_level = 0;


    ZoomControls zoomControls;
    int currentZoomLevel = 0;


    private static final String TAG = "AndroidCameraApi";
    private Button takePictureButton;
    private TextureView textureView;
    private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
    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 String cameraId;
    protected CameraDevice cameraDevice;
    protected CameraCaptureSession cameraCaptureSessions;
    protected CaptureRequest captureRequest;
    protected CaptureRequest.Builder captureRequestBuilder;
    private Size imageDimension;
    private ImageReader imageReader;
    private File file;
    private static final int REQUEST_CAMERA_PERMISSION = 200;
    private boolean mFlashSupported;
    private Handler mBackgroundHandler;
    private HandlerThread mBackgroundThread;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_magnifier);
        textureView = (TextureView) findViewById(R.id.texture);
        assert textureView != null;
        textureView.setSurfaceTextureListener(textureListener);
        takePictureButton = (Button) findViewById(R.id.btn_takepicture);
        assert takePictureButton != null;
        takePictureButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                takePicture();
            }
        });
        zoomControls = (ZoomControls) findViewById(R.id.zoomControls);
    }
    TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {
        @Override
        public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
            //open your camera here
            openCamera();
        }
        @Override
        public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
            // Transform you image captured size according to the surface width and height
        }
        @Override
        public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
            return false;
        }
        @Override
        public void onSurfaceTextureUpdated(SurfaceTexture surface) {
        }
    };
    private final CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {
        @Override
        public void onOpened(CameraDevice camera) {
            //This is called when the camera is open
            Log.e(TAG, "onOpened");
            cameraDevice = camera;
            createCameraPreview();
        }
        @Override
        public void onDisconnected(CameraDevice camera) {
            cameraDevice.close();
        }
        @Override
        public void onError(CameraDevice camera, int error) {
            cameraDevice.close();
            cameraDevice = null;
        }
    };
    final CameraCaptureSession.CaptureCallback captureCallbackListener = new CameraCaptureSession.CaptureCallback() {
        @Override
        public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
            super.onCaptureCompleted(session, request, result);
            Toast.makeText(MagnifierActivity.this, "Saved:" + file, Toast.LENGTH_SHORT).show();
            createCameraPreview();
        }
    };
    protected void startBackgroundThread() {
        mBackgroundThread = new HandlerThread("Camera Background");
        mBackgroundThread.start();
        mBackgroundHandler = new Handler(mBackgroundThread.getLooper());
    }
    protected void stopBackgroundThread() {
        mBackgroundThread.quitSafely();
        try {
            mBackgroundThread.join();
            mBackgroundThread = null;
            mBackgroundHandler = null;
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
    protected void takePicture() {
        if(null == cameraDevice) {
            Log.e(TAG, "cameraDevice is null");
            return;
        }
        CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        try {
            CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraDevice.getId());
            Size[] jpegSizes = null;
            if (characteristics != null) {
                jpegSizes = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP).getOutputSizes(ImageFormat.JPEG);
            }
            int width = 640;
            int height = 480;
            if (jpegSizes != null && 0 < jpegSizes.length) {
                width = jpegSizes[0].getWidth();
                height = jpegSizes[0].getHeight();
            }
            ImageReader reader = ImageReader.newInstance(width, height, ImageFormat.JPEG, 1);
            List<Surface> outputSurfaces = new ArrayList<Surface>(2);
            outputSurfaces.add(reader.getSurface());
            outputSurfaces.add(new Surface(textureView.getSurfaceTexture()));
            final CaptureRequest.Builder captureBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
            captureBuilder.addTarget(reader.getSurface());
            captureBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
            // Orientation
            int rotation = getWindowManager().getDefaultDisplay().getRotation();
            captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));
            final File file = new File(Environment.getExternalStorageDirectory()+"/pic.jpg");
            ImageReader.OnImageAvailableListener readerListener = new ImageReader.OnImageAvailableListener() {
                @Override
                public void onImageAvailable(ImageReader reader) {
                    Image image = null;
                    try {
                        image = reader.acquireLatestImage();
                        ByteBuffer buffer = image.getPlanes()[0].getBuffer();
                        byte[] bytes = new byte[buffer.capacity()];
                        buffer.get(bytes);
                        save(bytes);
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                        if (image != null) {
                            image.close();
                        }
                    }
                }
                private void save(byte[] bytes) throws IOException {
                    OutputStream output = null;
                    try {
                        output = new FileOutputStream(file);
                        output.write(bytes);
                    } finally {
                        if (null != output) {
                            output.close();
                        }
                    }
                }
            };
            reader.setOnImageAvailableListener(readerListener, mBackgroundHandler);
            final CameraCaptureSession.CaptureCallback captureListener = new CameraCaptureSession.CaptureCallback() {
                @Override
                public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
                    super.onCaptureCompleted(session, request, result);
                    Toast.makeText(MagnifierActivity.this, "Saved:" + file, Toast.LENGTH_SHORT).show();
                    createCameraPreview();
                }
            };
            cameraDevice.createCaptureSession(outputSurfaces, new CameraCaptureSession.StateCallback() {
                @Override
                public void onConfigured(CameraCaptureSession session) {
                    try {
                        session.capture(captureBuilder.build(), captureListener, mBackgroundHandler);
                    } catch (CameraAccessException e) {
                        e.printStackTrace();
                    }
                }
                @Override
                public void onConfigureFailed(CameraCaptureSession session) {
                }
            }, mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }
    protected void createCameraPreview() {
        try {
            SurfaceTexture texture = textureView.getSurfaceTexture();
            assert texture != null;
            texture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
            Surface surface = new Surface(texture);
            captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            captureRequestBuilder.addTarget(surface);
            cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback(){
                @Override
                public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
                    //The camera is already closed
                    if (null == cameraDevice) {
                        return;
                    }
                    // When the session is ready, we start displaying the preview.
                    cameraCaptureSessions = cameraCaptureSession;
                    updatePreview();
                }
                @Override
                public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
                    Toast.makeText(MagnifierActivity.this, "Configuration change", Toast.LENGTH_SHORT).show();
                }
            }, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }
    private void openCamera() {
        CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        Log.e(TAG, "is camera open");
        try {
            cameraId = manager.getCameraIdList()[0];
            CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
            StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
            assert map != null;
            imageDimension = map.getOutputSizes(SurfaceTexture.class)[0];
            // Add permission for camera and let user grant the permission
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                ActivityCompat.requestPermissions(MagnifierActivity.this, new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CAMERA_PERMISSION);
                return;
            }
            manager.openCamera(cameraId, stateCallback, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
        Log.e(TAG, "openCamera X");
    }
    protected void updatePreview() {
        if(null == cameraDevice) {
            Log.e(TAG, "updatePreview error, return");
        }
        captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
        try {
            cameraCaptureSessions.setRepeatingRequest(captureRequestBuilder.build(), null, mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }
    private void closeCamera() {
        if (null != cameraDevice) {
            cameraDevice.close();
            cameraDevice = null;
        }
        if (null != imageReader) {
            imageReader.close();
            imageReader = null;
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == REQUEST_CAMERA_PERMISSION) {
            if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
                // close the app
                Toast.makeText(MagnifierActivity.this, "Sorry!!!, you can't use this app without granting permission", Toast.LENGTH_LONG).show();
                finish();
            }
        }
    }
    @Override
    protected void onResume() {
        super.onResume();
        Log.e(TAG, "onResume");
        startBackgroundThread();
        if (textureView.isAvailable()) {
            openCamera();
        } else {
            textureView.setSurfaceTextureListener(textureListener);
        }
    }
    @Override
    protected void onPause() {
        Log.e(TAG, "onPause");
        //closeCamera();
        stopBackgroundThread();
        super.onPause();
    }


}
标签： android android-camera2
1条回答
兄弟一词,经得起流年.
2楼-- · 2019-08-23 14:39
You need to set the scaler crop region control for your still capture request (and the preview request, if you want to see what the zoom will be).
There are some diagrams here on how the crop works, targeted at the camera HAL implementers, but the policy is the same at the API layer too.
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implement zoom in Camera2 api. [closed]

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