在Camera2 API中实现缩放. [英] implement zoom in Camera2 api.
本文介绍了在Camera2 API中实现缩放.的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我是android的新手，正在使用android camera2 api.我无法在Camera2 API中实现缩放.我正在制作一个放大镜应用程序.我是否需要将设置更改为微距模式，否则自动对焦将为我做到这一点?我想使用ZoomContols实现缩放.请帮忙.谢谢.我已附上我的代码段.请告诉我如何实施.
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();
}
}
推荐答案
您需要设置缩放裁剪区域控制，用于仍然捕获的请求(以及预览请求，如果要查看缩放比例的话).
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).
此处有一些图表，针对的是针对相机的HAL实现者，但该策略在API层也相同.
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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