我正在尝试开发这个简单的拍照应用。一切都很好。我唯一在预览中心有一个固定大小的椭圆形 ImageView 。捕获图像工作正常，但问题是 我想捕获位于椭圆形 ImageView 内的图像并自动裁剪它。我不想保存整个图像，我只想要位于形状内的图像部分。 现在，我不知道如何继续。在谷歌上花了几个小时寻找解决方案后，我决定我不得不放弃并来到这里。我不明白我怎么才能只得到位于形状内的那部分图像(那个固定的椭圆形图像)。

这是我的代码:-

 public class MainActivity extends Activity implements SurfaceHolder.Callback {

    Camera camera;
    SurfaceView surfaceView;
    SurfaceHolder surfaceHolder;
    boolean cameraview = false;
    LayoutInflater inflater = null;
    private ImageView ImgContainer;
    private Button btn;
    private ImageView mIvCaptureImage;
    FrameLayout frameLayout;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

        getWindow().setFormat(PixelFormat.UNKNOWN);
        frameLayout = (FrameLayout) findViewById(R.id.view);
        surfaceView = (SurfaceView) findViewById(R.id.camera_preview);
        ImgContainer = (ImageView) findViewById(R.id.Img_container);
        surfaceHolder = surfaceView.getHolder();
        surfaceHolder.addCallback(this);
        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        // GuideBox box = new GuideBox(MainActivity.this);
        // llContainer.addView(box, new LayoutParams(LayoutParams.WRAP_CONTENT,
        // LayoutParams.WRAP_CONTENT));
        btn = (Button) findViewById(R.id.button);
        mIvCaptureImage = (ImageView) findViewById(R.id.imageview1);
        btn.setOnClickListener(new OnClickListener() {

            @SuppressWarnings("deprecation")
            @Override
            public void onClick(View v) {
                if (camera != null) {
                    camera.takePicture(myShutterCallback,
                            myPictureCallback_RAW, myPictureCallback_JPG);

                }

            }
        });

    }

    @TargetApi(Build.VERSION_CODES.GINGERBREAD)
    @SuppressWarnings("deprecation")
    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
            int height) {
        // TODO Auto-generated method stub
        if (cameraview) {
            camera.stopPreview();
            cameraview = false;
        }

        if (camera != null) {
            try {
                setCameraDisplayOrientation(this,
                        CameraInfo.CAMERA_FACING_BACK, camera);
                camera.setPreviewDisplay(surfaceHolder);
                camera.startPreview();
                cameraview = true;
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    @TargetApi(Build.VERSION_CODES.GINGERBREAD)
    @SuppressWarnings("deprecation")
    private void setCameraDisplayOrientation(Activity activity, int cameraId,
            android.hardware.Camera camera) {
        android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
        android.hardware.Camera.getCameraInfo(cameraId, info);
        int rotation = activity.getWindowManager().getDefaultDisplay()
                .getRotation();
        int degrees = 0;
        switch (rotation) {
        case Surface.ROTATION_0:
            degrees = 0;
            break;
        case Surface.ROTATION_90:
            degrees = 90;
            break;
        case Surface.ROTATION_180:
            degrees = 180;
            break;
        case Surface.ROTATION_270:
            degrees = 270;
            break;
        }

        int result;
        if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
            result = (info.orientation + degrees) % 360;
            result = (360 - result) % 360; // compensate the mirror
        } else { // back-facing
            result = (info.orientation - degrees + 360) % 360;
        }
        camera.setDisplayOrientation(result);
    }

    ShutterCallback myShutterCallback = new ShutterCallback() {

        public void onShutter() {
            // TODO Auto-generated method stub
        }
    };

    PictureCallback myPictureCallback_RAW = new PictureCallback() {

        @Override
        public void onPictureTaken(byte[] data, android.hardware.Camera camera) {
            // TODO Auto-generated method stub

        }
    };

    PictureCallback myPictureCallback_JPG = new PictureCallback() {

        @Override
        public void onPictureTaken(byte[] data, android.hardware.Camera camera) {
            // TODO Auto-generated method stub
            Rect rc = getViewPositionRelative();
            Bitmap bitmapPicture = BitmapFactory.decodeByteArray(data, 0,
                    data.length);
            Matrix mat = new Matrix();
            mat.postRotate(90);
            Bitmap correctBmp = Bitmap.createBitmap(bitmapPicture, rc.left,
                    rc.top, ImgContainer.getWidth(), ImgContainer.getHeight(),
                    mat, true);
            // Bitmap circularBitmap = ImageConverter.getRoundedCornerBitmap(
            // correctBmp, 100);
            mIvCaptureImage.setImageBitmap(correctBmp);
        }
    };

    public Rect getViewPositionRelative() {
        // Locate on screen
        int[] location = new int[2];
        ImgContainer.getLocationOnScreen(location); 

        Rect rect = new Rect();
        rect.left = location[0];
        rect.top = location[1];
        rect.right = rect.left + ImgContainer.getWidth();
        rect.bottom = rect.top + ImgContainer.getHeight();
        return rect;
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        camera = Camera.open();
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        camera.stopPreview();
        camera.release();
        camera = null;
        cameraview = false;
    }
}

第二种方法:-

PictureCallback myPictureCallback_JPG = new PictureCallback() {

    @Override
    public void onPictureTaken(byte[] data, android.hardware.Camera camera) {
        Boolean isSDPresent = android.os.Environment
                .getExternalStorageState().equals(
                        android.os.Environment.MEDIA_MOUNTED);

        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
                Locale.getDefault()).format(new Date());

        // checking for SD card
        if (isSDPresent) {
            mediaStorageDir = new File(Environment
                    .getExternalStorageDirectory().getAbsolutePath(),
                    IMAGE_DIRECTORY_NAME);

            mediaFile = new File(mediaStorageDir.getPath() + File.separator
                    + "IMG_" + timeStamp + ".jpg");

            // Create the storage directory if it does not exist
            if (!mediaStorageDir.exists()) {
                if (!mediaStorageDir.mkdirs()) {
                }
            }

            try {
                Bitmap userImage = BitmapFactory.decodeByteArray(data, 0,
                        data.length);

                // set file out stream
                FileOutputStream out = new FileOutputStream(mediaFile);
                // set compress format quality and stream
                userImage.compress(Bitmap.CompressFormat.JPEG, 100, out);

                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                userImage.compress(Bitmap.CompressFormat.JPEG, 100, baos);

                try {
                    out.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        } else {
            Toast.makeText(getApplicationContext(),
                    "Please insert SD card !", Toast.LENGTH_LONG).show();

        }
        if (mediaStorageDir.exists()) {
            getPathOfCapturedImage();
        }

    }
};

private void getPathOfCapturedImage() {
    final String ImagePath = mediaFile.getAbsolutePath();
    Bitmap bitmap = BitmapFactory.decodeFile(ImagePath);

    int bitWidth = bitmap.getWidth();
    int bitHeight = bitmap.getHeight();

    // 3. Size of camera preview on screen
    int preWidth = surfaceView.getWidth();
    int preHeight = surfaceView.getHeight();

    Rect rc = getViewPositionRelative();
    Matrix mat = new Matrix();
    mat.postRotate(90);

    int startx = rc.left * bitWidth / preWidth;
    int starty = rc.top * bitHeight / preHeight;
    int endx = rc.right * bitWidth / preWidth;
    int endy = rc.bottom * bitHeight / preHeight;

    Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, startx, starty,
            endx, endy);
    mIvCaptureImage.setImageBitmap(resizedBitmap);
}

public Rect getViewPositionRelative() {
    // Locate on screen
    int[] location = new int[2];
    ImgContainer.getLocationOnScreen(location);

    Rect rect = new Rect();
    rect.left = location[0];
    rect.top = location[1];
    rect.right = rect.left - ImgContainer.getWidth();
    rect.bottom = rect.top - ImgContainer.getHeight();
    return rect;
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
    // TODO Auto-generated method stub
    camera = Camera.open();
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    // TODO Auto-generated method stub
    camera.stopPreview();
    camera.release();
    camera = null;
    cameraview = false;
}

XML:-

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <FrameLayout
        android:id="@+id/view"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight=".6" >

        <SurfaceView
            android:id="@+id/camera_preview"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

        <ImageView
            android:id="@+id/Img_container"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/eclipce"/>
    </FrameLayout>

    <ImageView
        android:id="@+id/imageview1"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_weight=".2" />

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_gravity="center"
        android:layout_weight=".2"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:text="Capture" />
    </LinearLayout>

</LinearLayout>

所以，如果有人知道任何事情，请告诉我。

谢谢

最佳答案

一直在玩这个。这是我解决它的方法:

1) 只需拍下照片，就可以拍出漂亮的照片。是的，这比您想要的要多得多。

2) 获取叠加层的比例。现在您知道在哪里裁剪了。

3) 让计算机去做艰苦的计算工作，它很擅长。

我的 - 不完整 - 代码:(它的一部分，它在照片上绘制一个矩形以裁剪它)

ArrayList<int []> userPoints = new ArrayList<>();

/**
 * Method to Crop the image
 *
 * @param width             Width of the output image, in mm.
 * @param height            Height of the output image, in mm.
 */
private void cropImage(int width, int height) {
    Paint paint = new Paint();
    paint.setAntiAlias(false);
    paint.setFilterBitmap(false);

    int output_width_start = 0;
    int output_width_end = (width * 5) / 2;
    int output_height_start = 0;
    int output_height_end = (height * 5) / 2;

    Matrix matrix = new Matrix();
    matrix.setPolyToPoly(
            // where to take it from
            new float[]{
                    userPoints.get(0)[0], userPoints.get(0)[1],
                    userPoints.get(1)[0], userPoints.get(1)[1],
                    userPoints.get(2)[0], userPoints.get(2)[1],
                    userPoints.get(3)[0], userPoints.get(3)[1]},
            0,
            // what it should be
            new float[]{
                    output_width_start, output_height_start,
                    output_width_end, output_width_start,
                    output_width_end, output_height_end,
                    output_height_start, output_height_end},
            0, 4);

    Uri image_uri = Uri.fromFile(file); // get where the temp is stored
    Bitmap bitmap = BitmapFactory.decodeFile(image_uri.getPath());
    canvasRectangle.drawBitmap(bitmap, matrix, paint);
}

private void scaleImage(ImageView image) {
    Matrix matrix = image.getImageMatrix();
    RectF drawableRect = new RectF(userPoints.get(0)[0], userPoints.get(0)[1], 400, 300);
    RectF viewRect = new RectF(0, 0, imageViewPhoto.getWidth(), imageViewPhoto.getHeight());
    matrix.setRectToRect(drawableRect, viewRect, Matrix.ScaleToFit.CENTER);
    imageViewPhoto.setImageMatrix(matrix);
}

关于android - 拍摄覆盖范围内的照片，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37360426/