【问题标题】:Getting rotation from ExifInterface always returns 0从 ExifInterface 获取旋转总是返回 0
【发布时间】:2014-07-30 11:16:12
【问题描述】:

我正在从相机通过 onActivityResult 上的捆绑包传递位图。

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.TITLE, "picture");
mCapturedImageURI =     getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);

startActivityForResult(intent, REQUEST_TAKE_PHOTO); 

我可以得到位图:

Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), mCapturedImageURI);

但是,我注意到图像在某些设备上会旋转。在这里搜索帖子后,典型的解决方案似乎是通过以下方式获得轮换:

String path = mCapturedImageURI.getPath();
ExifInterface exif = new ExifInterface(path);
int rotation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

不幸的是,我的int rotation 始终为 0,即使位图已旋转。

我也尝试过这个方法,当我在设备上上传了一张图片但方向仍然是 0 时有效:

String[] orientationColumn = {MediaStore.Images.Media.ORIENTATION};
Cursor cur = managedQuery(mCapturedImageURI, orientationColumn, null, null, null);
if (cur != null && cur.moveToFirst()) {
      orientation = cur.getInt(cur.getColumnIndex(orientationColumn[0]));
}

有人看到我在这里做错了什么吗?还是其他解决方法?

一般情况下,后置摄像头逆时针旋转位图 90 度,前置摄像头顺时针旋转 90 度。在 Moto G 上工作正常。在 Galaxy S3 和 LG G2 上旋转。

【问题讨论】:

  • 三星设备出现旋转图像问题,ExifInterface 返回正确值。您可能需要在拍照时设置Exif Tag 值。 refer to
  • 代码看起来是正确的,我以前用过类似的东西。您使用的是标准相机应用还是自定义应用?

标签: android bitmap camera exif


【解决方案1】:

尝试使用内容光标中的信息。

float photoRotation = 0;
boolean hasRotation = false;
String[] projection = { Images.ImageColumns.ORIENTATION };
try {
    Cursor cursor = getActivity().getContentResolver().query(photoUri, projection, null, null, null);
    if (cursor.moveToFirst()) {
        photoRotation = cursor.getInt(0);
        hasRotation = true;
    }
    cursor.close();
} catch (Exception e) {}

if (!hasRotation) {
    ExifInterface exif = new ExifInterface(photoUri.getPath());
    int exifRotation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION,
            ExifInterface.ORIENTATION_UNDEFINED);

    switch (exifRotation) {
        case ExifInterface.ORIENTATION_ROTATE_90: {
            photoRotation = 90.0f;
            break;
        }
        case ExifInterface.ORIENTATION_ROTATE_180: {
            photoRotation = 180.0f;
            break;
        }
        case ExifInterface.ORIENTATION_ROTATE_270: {
            photoRotation = 270.0f;
            break;
        }
    }
}

【讨论】:

  • photoUri;您是通过EXTRA_OUTPUT 设置它还是通过data.getData() 从意图设置它?
  • 在我的例子中,它是 data.getData()。
  • 如果您使用的是三星设备,则使用光标是最好的方法,因为它们不会保存任何 exif 数据。感谢分享!
【解决方案2】:

试试这个方法,希望能帮助你解决问题。

activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:gravity="center">
        <ImageView
            android:id="@+id/imgFromCameraOrGallery"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:adjustViewBounds="true"
            android:src="@drawable/ic_launcher"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <Button
            android:id="@+id/btnCamera"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:text="Camera"/>
        <Button
            android:id="@+id/btnGallery"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_marginLeft="5dp"
            android:layout_height="wrap_content"
            android:text="Gallery"/>
    </LinearLayout>
</LinearLayout>

MainActivity.java:

public class MainActivity extends Activity {

    private ImageView imgFromCameraOrGallery;
    private Button btnCamera;
    private Button btnGallery;

    private String imgPath;
    final private int PICK_IMAGE = 1;
    final private int CAPTURE_IMAGE = 2;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imgFromCameraOrGallery = (ImageView) findViewById(R.id.imgFromCameraOrGallery);
        btnCamera = (Button) findViewById(R.id.btnCamera);
        btnGallery = (Button) findViewById(R.id.btnGallery);

        btnCamera.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                final Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                intent.putExtra(MediaStore.EXTRA_OUTPUT, setImageUri());
                startActivityForResult(intent, CAPTURE_IMAGE);
            }
        });

        btnGallery.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(Intent.createChooser(intent, ""), PICK_IMAGE);
            }
        });

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == Activity.RESULT_OK) {
            if (requestCode == CAPTURE_IMAGE) {
                rotateImage(getImagePath());
            } else if (requestCode == PICK_IMAGE) {
                imgFromCameraOrGallery.setImageBitmap(BitmapFactory.decodeFile(getAbsolutePath(data.getData())));
            }
        }

    }

    private void rotateImage(final String path) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                Bitmap b = decodeFileFromPath(path);
                try {
                    ExifInterface ei = new ExifInterface(path);
                    int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
                    Matrix matrix = new Matrix();
                    switch (orientation) {
                        case ExifInterface.ORIENTATION_ROTATE_90:
                            matrix.postRotate(90);
                            b = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), matrix, true);
                            break;
                        case ExifInterface.ORIENTATION_ROTATE_180:
                            matrix.postRotate(180);
                            b = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), matrix, true);
                            break;
                        case ExifInterface.ORIENTATION_ROTATE_270:
                            matrix.postRotate(270);
                            b = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), matrix, true);
                            break;
                        default:
                            b = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), matrix, true);
                            break;
                    }
                } catch (Throwable e) {
                    e.printStackTrace();
                }

                FileOutputStream out1 = null;
                File file;
                try {
                    String state = Environment.getExternalStorageState();
                    if (Environment.MEDIA_MOUNTED.equals(state)) {
                        file = new File(Environment.getExternalStorageDirectory() + "/DCIM/", "image" + new Date().getTime() + ".jpg");
                    }
                    else {
                        file = new File(getFilesDir() , "image" + new Date().getTime() + ".jpg");
                    }
                    out1 = new FileOutputStream(file);
                    b.compress(Bitmap.CompressFormat.JPEG, 90, out1);
                    imgFromCameraOrGallery.setImageBitmap(BitmapFactory.decodeFile(file.getAbsolutePath()));
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    try {
                        out1.close();
                    } catch (Throwable ignore) {

                    }
                }

            }
        });

    }

    private Bitmap decodeFileFromPath(String path){
        Uri uri = getImageUri(path);
        InputStream in = null;
        try {
            in = getContentResolver().openInputStream(uri);

            //Decode image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;

            BitmapFactory.decodeStream(in, null, o);
            in.close();


            int scale = 1;
            int inSampleSize = 1024;
            if (o.outHeight > inSampleSize || o.outWidth > inSampleSize) {
                scale = (int) Math.pow(2, (int) Math.round(Math.log(inSampleSize / (double) Math.max(o.outHeight, o.outWidth)) / Math.log(0.5)));
            }

            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
            in = getContentResolver().openInputStream(uri);
            Bitmap b = BitmapFactory.decodeStream(in, null, o2);
            in.close();

            return b;

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

    public String getAbsolutePath(Uri uri) {
        if(Build.VERSION.SDK_INT >= 19){
            String id = uri.getLastPathSegment().split(":")[1];
            final String[] imageColumns = {MediaStore.Images.Media.DATA };
            final String imageOrderBy = null;
            Uri tempUri = getUri();
            Cursor imageCursor = getContentResolver().query(tempUri, imageColumns,
                    MediaStore.Images.Media._ID + "="+id, null, imageOrderBy);
            if (imageCursor.moveToFirst()) {
                return imageCursor.getString(imageCursor.getColumnIndex(MediaStore.Images.Media.DATA));
            }else{
                return null;
            }
        }else{
            String[] projection = { MediaStore.MediaColumns.DATA };
            Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
            if (cursor != null) {
                int column_index = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
                cursor.moveToFirst();
                return cursor.getString(column_index);
            } else
                return null;
        }

    }

    private Uri getUri() {
        String state = Environment.getExternalStorageState();
        if(!state.equalsIgnoreCase(Environment.MEDIA_MOUNTED))
            return MediaStore.Images.Media.INTERNAL_CONTENT_URI;

        return MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
    }

    private Uri getImageUri(String path) {
        return Uri.fromFile(new File(path));
    }

    public Uri setImageUri() {

        String state = Environment.getExternalStorageState();
        if (Environment.MEDIA_MOUNTED.equals(state)) {
            File file = new File(Environment.getExternalStorageDirectory() + "/DCIM/", "image" + new Date().getTime() + ".jpg");
            Uri imgUri = Uri.fromFile(file);
            this.imgPath = file.getAbsolutePath();
            return imgUri;
        }
        else {
            File file = new File(getFilesDir() , "image" + new Date().getTime() + ".jpg");
            Uri imgUri = Uri.fromFile(file);
            this.imgPath = file.getAbsolutePath();
            return imgUri;
        }
    }

    public String getImagePath() {
        return imgPath;
    }

}

【讨论】:

  • 对于imgFromCameraOrGallery.setImageBitmap(BitmapFactory.decodeFile(getAbsolutePath(data.getData())));data 为空
  • 你测试了哪台设备?
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