Question

在我的Android编码中我有一个摄像头表面视图类，当我显示这个摄像头类的预览时，它是一个实时摄像头场景，但是如何创建一个为摄像头当前帧创建位图的功能？所以我可以从其他类中获取捕获的位图。

任何指导都将受到赞赏〜

这是我的相机类编码：

import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.io.IOException;

public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback {

Camera mCamera;
boolean isPreviewRunning = false;

CameraSurfaceView(Context context) {
    super(context);
    SurfaceHolder mHolder = getHolder();
    mHolder.addCallback(this);
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

public void surfaceCreated(SurfaceHolder holder) {
    synchronized(this) {
        mCamera = Camera.open();
        try {
            mCamera.setPreviewDisplay(holder);
        } catch (IOException e) {
            Log.e("Camera", "mCamera.setPreviewDisplay(holder);");
        }
        mCamera.setDisplayOrientation(90);
        mCamera.startPreview();

    }
}

public void surfaceDestroyed(SurfaceHolder holder) {
    synchronized(this) {
        try {
            if (mCamera!=null) {
                mCamera.stopPreview();
                isPreviewRunning=false;
                mCamera.release();
            }
        } catch (Exception e) {
            Log.e("Camera", e.getMessage());
        }
    }
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {

}

}

Answer 1

请注意，以下代码用于捕获图像及其显示的像素，而不是拍摄相机。这意味着，结果图像将给出屏幕（即1080x768）的实际像素大小，而不是相机应用程序的数百万像素高分辨率图像。如果您想将图像作为相机应用提供，请使用takePicture方法。

为了在SurfaceView，

中捕捉实时预览图像

public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback {
    private static final String TAG = "CameraSurfaceView";

    private SurfaceHolder mSurfaceHolder;
    private Camera mCamera = null;
    private Bitmap mBitmap;
    private Context mContext;
    private Camera.Parameters mParameters;
    private byte[] byteArray;
    private List<Camera.Size> mSupportedPreviewSizes;
    private Camera.Size mPreviewSize;

    public CameraSurfaceView (Context context) {
        this(context, null);
    }

    public CameraSurfaceView (Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public CameraSurfaceView (Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        mContext = context;

        try {
            mSurfaceHolder = getHolder();
            mSurfaceHolder.addCallback(this);
            mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void surfaceCreated(final SurfaceHolder surfaceHolder) {
        if (mCamera == null) {
            try {
                mCamera = Camera.open();
            } catch (RuntimeException ignored) {
            }
        }

        try {
            if (mCamera != null) {
                WindowManager winManager = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
                mCamera.setPreviewDisplay(mSurfaceHolder);
            }
        } catch (Exception e) {
            if (mCamera != null)
                mCamera.release();
            mCamera = null;
        }

        if (mCamera == null) {
                return;
        } else {
            mCamera.setPreviewCallback(new Camera.PreviewCallback() {
                @Override
                public void onPreviewFrame(byte[] bytes, Camera camera) {
                    if (mParameters == null)
                    {
                        return;
                    }
                    byteArray = bytes;
                }
            });
        }

        setWillNotDraw(false);
    }

    @Override
    public void surfaceChanged(SurfaceHolder surfaceHolder, int format, int width, int height) {
        try {
            mParameters = mCamera.getParameters();

            List<Size> cameraSize = mParameters.getSupportedPreviewSizes();
            mPreviewSize = cameraSize.get(0);

            for (Size s : cameraSize) {
                if ((s.width * s.height) > (mPreviewSize.width * mPreviewSize.height)) {
                    mPreviewSize = s;
                }
            }

            mParameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
            mCamera.setParameters(mParameters);
            mCamera.startPreview();

        } catch (Exception e) {
            if (mCamera != null) {
                mCamera.release();
                mCamera = null;
            }
        }
    }


    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
        if (mCamera != null) {
            mCamera.setPreviewCallback(null);
            mCamera.stopPreview();
            mCamera.release();
            mCamera = null;
        }
    }

    public Bitmap getBitmap() {
        try {
            if (mParameters == null)
                return null;

            if (mPreviewSize == null)
                return null;

            int format = mParameters.getPreviewFormat();
            YuvImage yuvImage = new YuvImage(byteArray, format, mPreviewSize.width, mPreviewSize.height, null);
            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();

            Rect rect = new Rect(0, 0, mPreviewSize.width, mPreviewSize.height);

            yuvImage.compressToJpeg(rect, 75, byteArrayOutputStream);
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inPurgeable = true;
            options.inInputShareable = true;
            mBitmap = BitmapFactory.decodeByteArray(byteArrayOutputStream.toByteArray(), 0, byteArrayOutputStream.size(), options);

            byteArrayOutputStream.flush();
            byteArrayOutputStream.close();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }

        return mBitmap;
    }

    public Camera getCamera() {
        return mCamera;
    }
}

Android相机捕获位图

1 个答案: