如何旋转使用 takePicture 捕获的图像？答案

【问题标题】：how to rotate Image captured using takePicture?如何旋转使用 takePicture 捕获的图像？
【发布时间】：2015-01-12 11:48:15
【问题描述】：

我准备的视图（使用 setDisplayOrientation()）处于纵向模式，但生成的图像（使用 takePicture() 拍摄，使用 SaveImageTask 保存）处于横向模式。

这是我的预览和捕获代码：

public void startPreview() {
    this.mCamera.setDisplayOrientation(90);
    try {
        this.mCamera.setPreviewDisplay(this.mSurfaceHolder);
        this.mCamera.startPreview();
     } catch (Exception e) {
        Log.d("camera" , "in startPreview Catch");
     }
}

public void captureNow(View view) {
    this.mCamera.takePicture(shutterCallback, rawCallback, jpegCallback);
    this.startPreview();
}

这是我捕获的图像保存代码：

public class SaveImageTask extends AsyncTask<byte[], Void, Void> {
    @Override
    protected Void doInBackground(byte[]... data) {
        FileOutputStream outStream = null;
        // Write to SD Card
        try {
            File dir = new File(
            Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_PICTURES), "camTest");
            dir.mkdirs();
            String fileName = String.format("%d.jpg", System.currentTimeMillis());
            File outFile = new File(dir, fileName);
            outStream = new FileOutputStream(outFile);
            outStream.write(data[0]);
            outStream.flush();
            outStream.close();

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
        }
        return null;
    }
}

如何旋转捕获的图像？传感器似乎始终处于横向模式。（注：API 21）

【问题讨论】：

标签： android android-camera

【解决方案1】：

我正在发布我的部分代码，可能会对您有所帮助，谢谢

        File f = new File(path + "image" + imagecount + ".jpg");
        ExifInterface exif = new ExifInterface(f.getPath());
        int orientation = exif.getAttributeInt(
                ExifInterface.TAG_ORIENTATION,
                ExifInterface.ORIENTATION_NORMAL);

        int angle = 0;

        if (orientation == ExifInterface.ORIENTATION_ROTATE_90) {
            angle = 90;
        } else if (orientation == ExifInterface.ORIENTATION_ROTATE_180) {
            angle = 180;
        } else if (orientation == ExifInterface.ORIENTATION_ROTATE_270) {
            angle = 270;
        }

        Matrix mat = new Matrix();
        mat.postRotate(angle);
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inSampleSize = 3;

        Bitmap bmp = BitmapFactory.decodeStream(new FileInputStream(f),
                null, options);
        correctBmp = Bitmap.createBitmap(bmp, 0, 0, bmp.getWidth(),
                bmp.getHeight(), mat, true);
        ByteArrayOutputStream outstudentstreamOutputStream =                           new ByteArrayOutputStream();
        correctBmp.compress(Bitmap.CompressFormat.PNG, 100,
                outstudentstreamOutputStream);
        capturedImageIV.setImageBitmap(correctBmp);
    } catch (IOException e) {
        Log.w("TAG", "-- Error in setting image");
    } catch (OutOfMemoryError oom) {
        Log.w("TAG", "-- OOM Error in setting image");
    }

【讨论】：

【解决方案2】：

如果你想在拍照前改变方向，你必须先配置相机。

public void onOrientationChanged(int orientation) {
   if (orientation == ORIENTATION_UNKNOWN) return;
   android.hardware.Camera.CameraInfo info =
        new android.hardware.Camera.CameraInfo();
   android.hardware.Camera.getCameraInfo(cameraId, info);
   orientation = (orientation + 45) / 90 * 90;
   int rotation = 0;
   if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
     rotation = (info.orientation - orientation + 360) % 360;
   } else {  // back-facing camera
     rotation = (info.orientation + orientation) % 360;
   }
   mParameters.setRotation(rotation);
}

AFAIK，您不能在写入光盘之前更改 exif 数据。所以，如果你以后想改变方向，你可以按照 Arun Antoney 的方式来做。

【讨论】：