为什么在Android上的某些设备上使用相机意图捕获的图像会被旋转？

Question

我正在捕捉图像并将其设置为图像视图.

public void captureImage() {

    Intent intentCamera = new Intent("android.media.action.IMAGE_CAPTURE");
    File filePhoto = new File(Environment.getExternalStorageDirectory(), "Pic.jpg");
    imageUri = Uri.fromFile(filePhoto);
    MyApplicationGlobal.imageUri = imageUri.getPath();
    intentCamera.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
    startActivityForResult(intentCamera, TAKE_PICTURE);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intentFromCamera) {
    super.onActivityResult(requestCode, resultCode, intentFromCamera);

    if (resultCode == RESULT_OK && requestCode == TAKE_PICTURE) {

        if (intentFromCamera != null) {
            Bundle extras = intentFromCamera.getExtras();
            if (extras.containsKey("data")) {
                bitmap = (Bitmap) extras.get("data");
            }
            else {
                bitmap = getBitmapFromUri();
            }
        }
        else {
            bitmap = getBitmapFromUri();
        }
        // imageView.setImageBitmap(bitmap);
        imageView.setImageURI(imageUri);
    }
    else {
    }
}

public Bitmap getBitmapFromUri() {

    getContentResolver().notifyChange(imageUri, null);
    ContentResolver cr = getContentResolver();
    Bitmap bitmap;

    try {
        bitmap = android.provider.MediaStore.Images.Media.getBitmap(cr, imageUri);
        return bitmap;
    }
    catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}

但问题是,每次旋转时某些设备上的图像.例如,在三星设备上它运行良好,但在Sony Xperia上,图像旋转了90度,在Toshiba Thrive(平板电脑)上旋转了180度.

Answer 1

大多数手机摄像头都是风景照片,这意味着如果您拍摄照片,拍摄的照片将旋转90度.在这种情况下,相机软件应使用应在其中查看照片的方向填充Exif数据.

请注意,以下解决方案取决于填充Exif数据的相机软件/设备制造商,因此它在大多数情况下都可以使用,但它不是100%可靠的解决方案.

ExifInterface ei = new ExifInterface(photoPath);
int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION,
                                     ExifInterface.ORIENTATION_UNDEFINED);

Bitmap rotatedBitmap = null;
switch(orientation) {

    case ExifInterface.ORIENTATION_ROTATE_90:
        rotatedBitmap = rotateImage(bitmap, 90);
        break;

    case ExifInterface.ORIENTATION_ROTATE_180:
        rotatedBitmap = rotateImage(bitmap, 180);
        break;

    case ExifInterface.ORIENTATION_ROTATE_270:
        rotatedBitmap = rotateImage(bitmap, 270);
        break;

    case ExifInterface.ORIENTATION_NORMAL:
    default:
        rotatedBitmap = bitmap;
}

这是rotateImage方法:

public static Bitmap rotateImage(Bitmap source, float angle) {
    Matrix matrix = new Matrix();
    matrix.postRotate(angle);
    return Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(),
                               matrix, true);
}

Answer 2

通过将Jason Robinson的回答与Felix的答案相结合并填补缺失的部分,这是此问题的最终完整解决方案,在Android Android 4.1(Jelly Bean),Android 4.4(KitKat)和Android 5.0(Lollipop).

脚步

1. 如果图像大于1024x1024,则缩小图像.

2. 只有在旋转90度,180度或270度时,才能将图像旋转到正确的方向.

3. 为了记忆目的,回收旋转的图像.

这是代码部分:

使用要修复的当前Context和图像调用以下方法URI

/**
 * This method is responsible for solving the rotation issue if exist. Also scale the images to
 * 1024x1024 resolution
 *
 * @param context       The current context
 * @param selectedImage The Image URI
 * @return Bitmap image results
 * @throws IOException
 */
public static Bitmap handleSamplingAndRotationBitmap(Context context, Uri selectedImage)
        throws IOException {
    int MAX_HEIGHT = 1024;
    int MAX_WIDTH = 1024;

    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    InputStream imageStream = context.getContentResolver().openInputStream(selectedImage);
    BitmapFactory.decodeStream(imageStream, null, options);
    imageStream.close();

    // Calculate inSampleSize
    options.inSampleSize = calculateInSampleSize(options, MAX_WIDTH, MAX_HEIGHT);

    // Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    imageStream = context.getContentResolver().openInputStream(selectedImage);
    Bitmap img = BitmapFactory.decodeStream(imageStream, null, options);

    img = rotateImageIfRequired(context, img, selectedImage);
    return img;
}

这是CalculateInSampleSize前面提到的来源的方法:

/**
  * Calculate an inSampleSize for use in a {@link BitmapFactory.Options} object when decoding
  * bitmaps using the decode* methods from {@link BitmapFactory}. This implementation calculates
  * the closest inSampleSize that will result in the final decoded bitmap having a width and
  * height equal to or larger than the requested width and height. This implementation does not
  * ensure a power of 2 is returned for inSampleSize which can be faster when decoding but
  * results in a larger bitmap which isn't as useful for caching purposes.
  *
  * @param options   An options object with out* params already populated (run through a decode*
  *                  method with inJustDecodeBounds==true
  * @param reqWidth  The requested width of the resulting bitmap
  * @param reqHeight The requested height of the resulting bitmap
  * @return The value to be used for inSampleSize
  */
private static int calculateInSampleSize(BitmapFactory.Options options,
                                         int reqWidth, int reqHeight) {
    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (height > reqHeight || width > reqWidth) {

        // Calculate ratios of height and width to requested height and width
        final int heightRatio = Math.round((float) height / (float) reqHeight);
        final int widthRatio = Math.round((float) width / (float) reqWidth);

        // Choose the smallest ratio as inSampleSize value, this will guarantee a final image
        // with both dimensions larger than or equal to the requested height and width.
        inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;

        // This offers some additional logic in case the image has a strange
        // aspect ratio. For example, a panorama may have a much larger
        // width than height. In these cases the total pixels might still
        // end up being too large to fit comfortably in memory, so we should
        // be more aggressive with sample down the image (=larger inSampleSize).

        final float totalPixels = width * height;

        // Anything more than 2x the requested pixels we'll sample down further
        final float totalReqPixelsCap = reqWidth * reqHeight * 2;

        while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) {
            inSampleSize++;
        }
    }
    return inSampleSize;
}

然后是检查当前图像方向以确定旋转角度的方法

 /**
 * Rotate an image if required.
 *
 * @param img           The image bitmap
 * @param selectedImage Image URI
 * @return The resulted Bitmap after manipulation
 */
private static Bitmap rotateImageIfRequired(Context context, Bitmap img, Uri selectedImage) throws IOException {

InputStream input = context.getContentResolver().openInputStream(selectedImage);
ExifInterface ei;
if (Build.VERSION.SDK_INT > 23)
    ei = new ExifInterface(input);
else
    ei = new ExifInterface(selectedImage.getPath());

    int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

    switch (orientation) {
        case ExifInterface.ORIENTATION_ROTATE_90:
            return rotateImage(img, 90);
        case ExifInterface.ORIENTATION_ROTATE_180:
            return rotateImage(img, 180);
        case ExifInterface.ORIENTATION_ROTATE_270:
            return rotateImage(img, 270);
        default:
            return img;
    }
}

最后是旋转方法本身

private static Bitmap rotateImage(Bitmap img, int degree) {
    Matrix matrix = new Matrix();
    matrix.postRotate(degree);
    Bitmap rotatedImg = Bitmap.createBitmap(img, 0, 0, img.getWidth(), img.getHeight(), matrix, true);
    img.recycle();
    return rotatedImg;
}

- 不要忘记为那些家伙的努力投票和Shirish Herwade,他们提出这个有用的问题.

Answer 3

使用以下方法可以轻松检测图像方向并替换位图:

 /**
 * Rotate an image if required.
 * @param img
 * @param selectedImage
 * @return
 */
private static Bitmap rotateImageIfRequired(Context context,Bitmap img, Uri selectedImage) {

    // Detect rotation
    int rotation = getRotation(context, selectedImage);
    if (rotation != 0) {
        Matrix matrix = new Matrix();
        matrix.postRotate(rotation);
        Bitmap rotatedImg = Bitmap.createBitmap(img, 0, 0, img.getWidth(), img.getHeight(), matrix, true);
        img.recycle();
        return rotatedImg;
    }
    else{
        return img;
    }
}

/**
 * Get the rotation of the last image added.
 * @param context
 * @param selectedImage
 * @return
 */
private static int getRotation(Context context,Uri selectedImage) {

    int rotation = 0;
    ContentResolver content = context.getContentResolver();

    Cursor mediaCursor = content.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                                       new String[] { "orientation", "date_added" },
                                       null, null, "date_added desc");

    if (mediaCursor != null && mediaCursor.getCount() != 0) {
        while(mediaCursor.moveToNext()){
            rotation = mediaCursor.getInt(0);
            break;
        }
    }
    mediaCursor.close();
    return rotation;
}

为避免出现大图像的记忆,我建议您使用以下方法重新缩放图像:

private static final int MAX_HEIGHT = 1024;
private static final int MAX_WIDTH = 1024;
public static Bitmap decodeSampledBitmap(Context context, Uri selectedImage)
    throws IOException {

    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    InputStream imageStream = context.getContentResolver().openInputStream(selectedImage);
    BitmapFactory.decodeStream(imageStream, null, options);
    imageStream.close();

    // Calculate inSampleSize
    options.inSampleSize = calculateInSampleSize(options, MAX_WIDTH, MAX_HEIGHT);

    // Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    imageStream = context.getContentResolver().openInputStream(selectedImage);
    Bitmap img = BitmapFactory.decodeStream(imageStream, null, options);

    img = rotateImageIfRequired(img, selectedImage);
    return img;
}

由于Android操作系统问题,使用ExifInterface来获取方向是不可行的:https://code.google.com/p/android/issues/detail？ id = 19268

这是 calculateInSampleSize

/**
 * Calculate an inSampleSize for use in a {@link BitmapFactory.Options} object when decoding
 * bitmaps using the decode* methods from {@link BitmapFactory}. This implementation calculates
 * the closest inSampleSize that will result in the final decoded bitmap having a width and
 * height equal to or larger than the requested width and height. This implementation does not
 * ensure a power of 2 is returned for inSampleSize which can be faster when decoding but
 * results in a larger bitmap which isn't as useful for caching purposes.
 *
 * @param options   An options object with out* params already populated (run through a decode*
 *                  method with inJustDecodeBounds==true
 * @param reqWidth  The requested width of the resulting bitmap
 * @param reqHeight The requested height of the resulting bitmap
 * @return The value to be used for inSampleSize
 */
public static int calculateInSampleSize(BitmapFactory.Options options,
                                        int reqWidth, int reqHeight) {

    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (height > reqHeight || width > reqWidth) {

        // Calculate ratios of height and width to requested height and width
        final int heightRatio = Math.round((float) height / (float) reqHeight);
        final int widthRatio = Math.round((float) width / (float) reqWidth);

        // Choose the smallest ratio as inSampleSize value, this will guarantee a final image
        // with both dimensions larger than or equal to the requested height and width.
        inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;

        // This offers some additional logic in case the image has a strange
        // aspect ratio. For example, a panorama may have a much larger
        // width than height. In these cases the total pixels might still
        // end up being too large to fit comfortably in memory, so we should
        // be more aggressive with sample down the image (=larger inSampleSize).

        final float totalPixels = width * height;

        // Anything more than 2x the requested pixels we'll sample down further
        final float totalReqPixelsCap = reqWidth * reqHeight * 2;

        while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) {
            inSampleSize++;
        }
    }
    return inSampleSize;
}

Answer 4

一线解决方案:

Picasso.with(context).load("http://i.imgur.com/DvpvklR.png").into(imageView);

要么

Picasso.with(context).load("file:" + photoPath).into(imageView);

这将自动检测旋转并将图像放置在正确的方向

Picasso是一个非常强大的库,用于处理应用程序中的图像,包括: 复杂的图像转换,内存使用最少.

Answer 5

// Try this way,hope this will help you to solve your problem...

activity_main.xml中

<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) {
                setCapturedImage(getImagePath());
            } else if (requestCode == PICK_IMAGE) {
                imgFromCameraOrGallery.setImageBitmap(BitmapFactory.decodeFile(getAbsolutePath(data.getData())));
            }
        }

    }

    private String getRightAngleImage(String photoPath) {

        try {
            ExifInterface ei = new ExifInterface(photoPath);
            int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
            int degree = 0;

            switch (orientation) {
                case ExifInterface.ORIENTATION_NORMAL:
                    degree = 0;
                    break;
                case ExifInterface.ORIENTATION_ROTATE_90:
                    degree = 90;
                    break;
                case ExifInterface.ORIENTATION_ROTATE_180:
                    degree = 180;
                    break;
                case ExifInterface.ORIENTATION_ROTATE_270:
                    degree = 270;
                    break;
                case ExifInterface.ORIENTATION_UNDEFINED:
                    degree = 0;
                    break;
                default:
                    degree = 90;
            }

            return rotateImage(degree,photoPath);

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

        return photoPath;
    }

    private String rotateImage(int degree, String imagePath){

        if(degree<=0){
            return imagePath;
        }
        try{
            Bitmap b= BitmapFactory.decodeFile(imagePath);

            Matrix matrix = new Matrix();
            if(b.getWidth()>b.getHeight()){
                matrix.setRotate(degree);
                b = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(),
                        matrix, true);
            }

            FileOutputStream fOut = new FileOutputStream(imagePath);
            String imageName = imagePath.substring(imagePath.lastIndexOf("/") + 1);
            String imageType = imageName.substring(imageName.lastIndexOf(".") + 1);

            FileOutputStream out = new FileOutputStream(imagePath);
            if (imageType.equalsIgnoreCase("png")) {
                b.compress(Bitmap.CompressFormat.PNG, 100, out);
            }else if (imageType.equalsIgnoreCase("jpeg")|| imageType.equalsIgnoreCase("jpg")) {
                b.compress(Bitmap.CompressFormat.JPEG, 100, out);
            }
            fOut.flush();
            fOut.close();

            b.recycle();
        }catch (Exception e){
            e.printStackTrace();
        }
        return imagePath;
    }

    private void setCapturedImage(final String imagePath){
        new AsyncTask<Void,Void,String>(){
            @Override
            protected String doInBackground(Void... params) {
                try {
                    return getRightAngleImage(imagePath);
                }catch (Throwable e){
                    e.printStackTrace();
                }
                return imagePath;
            }

            @Override
            protected void onPostExecute(String imagePath) {
                super.onPostExecute(imagePath);
                imgFromCameraOrGallery.setImageBitmap(decodeFile(imagePath));
            }
        }.execute();
    }

    public Bitmap decodeFile(String path) {
        try {
            // Decode deal_image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(path, o);
            // The new size we want to scale to
            final int REQUIRED_SIZE = 1024;

            // Find the correct scale value. It should be the power of 2.
            int scale = 1;
            while (o.outWidth / scale / 2 >= REQUIRED_SIZE && o.outHeight / scale / 2 >= REQUIRED_SIZE)
                scale *= 2;
            // Decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
            return BitmapFactory.decodeFile(path, o2);
        } catch (Throwable e) {
            e.printStackTrace();
        }
        return null;
    }

    public String getAbsolutePath(Uri uri) {
        if(Build.VERSION.SDK_INT >= 19){
            String id = "";
            if(uri.getLastPathSegment().split(":").length > 1)
                id = uri.getLastPathSegment().split(":")[1];
            else if(uri.getLastPathSegment().split(":").length > 0)
                id = uri.getLastPathSegment().split(":")[0];
            if(id.length() > 0){
                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{
                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;
    }

    public Uri setImageUri() {
        Uri imgUri;
        String state = Environment.getExternalStorageState();
        if (Environment.MEDIA_MOUNTED.equals(state)) {
            File file = new File(Environment.getExternalStorageDirectory() + "/DCIM/",getString(R.string.app_name) + Calendar.getInstance().getTimeInMillis() + ".png");
            imgUri = Uri.fromFile(file);
            imgPath = file.getAbsolutePath();
        }else {
            File file = new File(getFilesDir() ,getString(R.string.app_name) + Calendar.getInstance().getTimeInMillis()+ ".png");
            imgUri = Uri.fromFile(file);
            this.imgPath = file.getAbsolutePath();
        }
        return imgUri;
    }

    public String getImagePath() {
        return imgPath;
    }
}

Answer 6

你可以在文档中阅读相机传感器的方向,如Google所示:https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html

SENSOR_ORIENTATION

Added in API level 21
Key<Integer> SENSOR_ORIENTATION
Clockwise angle through which the output image needs to be rotated to be upright on the device screen in its native orientation.

Also defines the direction of rolling shutter readout, which is from top to bottom in the sensor's coordinate system.

Units: Degrees of clockwise rotation; always a multiple of 90

Range of valid values:
0, 90, 180, 270

This key is available on all devices.

示例代码:

CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
int orientation = 0;
try {
    String cameraId = manager.getCameraIdList()[0];
    CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
    orientation = characteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);
}
catch (Exception e)
{
}

Answer 7

我花了很多时间寻找解决方案。最后设法做到了。不要忘记赞@Jason Robinson的答案，因为我是基于他的。

因此，第一件事，您应该知道，从Android 7.0开始，我们必须使用FileProvider和所谓的东西ContentUri，否则您尝试调用时会遇到烦人的错误Intent。这是示例代码：

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, getUriFromPath(context, "[Your path to save image]"));
startActivityForResult(intent, CAPTURE_IMAGE_RESULT);

getUriFromPath(Context, String)基于Android create FileUri (file://...)或更高版本的用户的方法ContentUri (content://...)有：

public Uri getUriFromPath(Context context, String destination) {
    File file =  new File(destination);

    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
        return FileProvider.getUriForFile(context, context.getPackageName() + ".provider", file);
    } else {
        return Uri.fromFile(file);
    }
}

在onActivityResult您可以捕捉到uri相机保存图像的位置之后，但是现在您必须检测相机旋转之后，在这里我们将使用修改后的@Jason Robinson答案：

首先我们需要创建ExifInterface基于Uri

@Nullable
public ExifInterface getExifInterface(Context context, Uri uri) {
    try {
        String path = uri.toString();
        if (path.startsWith("file://")) {
            return new ExifInterface(path);
        }
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            if (path.startsWith("content://")) {
                InputStream inputStream = context.getContentResolver().openInputStream(uri);
                return new ExifInterface(inputStream);
            }
        }
    }
    catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

上面的代码可以简化，但是我想展示一切。因此，FileUri我们可以ExifInterface基于创建String path，但我们不能基于ContentUriAndroid。

在这种情况下，我们必须使用基于的其他构造函数InputStream。请记住，默认情况下此构造函数不可用，您必须添加其他库：

compile "com.android.support:exifinterface:XX.X.X"

现在我们可以使用getExifInterfacemethod来获取角度：

public float getExifAngle(Context context, Uri uri) {
    try {
        ExifInterface exifInterface = getExifInterface(context, uri);
        if(exifInterface == null) {
            return -1f;
        }

        int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION,
                ExifInterface.ORIENTATION_UNDEFINED);

        switch (orientation) {
            case ExifInterface.ORIENTATION_ROTATE_90:
                return 90f;
            case ExifInterface.ORIENTATION_ROTATE_180:
                return 180f;
            case ExifInterface.ORIENTATION_ROTATE_270:
                return 270f;
            case ExifInterface.ORIENTATION_NORMAL:
                return 0f;
            case ExifInterface.ORIENTATION_UNDEFINED:
                return -1f;
            default:
                return -1f;
        }
    }
    catch (Exception e) {
        e.printStackTrace();
        return -1f;
    }
}

现在，您可以使用角度正确旋转图像了：）。

Answer 8

杰森·罗宾逊（Jason Robinson）的答案和萨米（Sami Eltamawy）的答案都很出色。

只是为了完成方法的一项改进，您应该使用compat ExifInterface。

com.android.support:exifinterface:${lastLibVersion}

您将能够使用InputStream（from ContentResolver）实例化ExifInterface（pior API <24 ）而不是uri路径，从而避免出现“找不到文件异常”

https://android-developers.googleblog.com/2016/12/introducing-the-exifinterface-support-library.html

Answer 9

我根据 @Jason Robinson 的回答创建了一个 Kotlin 扩展函数，可以简化 Kotlin 开发人员的操作。我希望它有帮助。

fun Bitmap.fixRotation(uri: Uri): Bitmap? {

    val ei = ExifInterface(uri.path)

    val orientation: Int = ei.getAttributeInt(
        ExifInterface.TAG_ORIENTATION,
        ExifInterface.ORIENTATION_UNDEFINED
    )

    return when (orientation) {
        ExifInterface.ORIENTATION_ROTATE_90 -> rotateImage( 90f)
        ExifInterface.ORIENTATION_ROTATE_180 -> rotateImage( 180f)
        ExifInterface.ORIENTATION_ROTATE_270 -> rotateImage( 270f)
        ExifInterface.ORIENTATION_NORMAL -> this
        else -> this
    }
}

fun Bitmap.rotateImage(angle: Float): Bitmap? {
    val matrix = Matrix()
    matrix.postRotate(angle)
    return Bitmap.createBitmap(
        this, 0, 0, width, height,
        matrix, true
    )
}

Answer 10

我用不同的方法解决了它。您所要做的就是检查宽度是否大于高度

Matrix rotationMatrix = new Matrix();
if(finalBitmap.getWidth() >= finalBitmap.getHeight()){
    rotationMatrix.setRotate(-90);
}else{
    rotationMatrix.setRotate(0);
}

Bitmap rotatedBitmap = Bitmap.createBitmap(finalBitmap,0,0,finalBitmap.getWidth(),finalBitmap.getHeight(),rotationMatrix,true);

Answer 11

这是一个基于上述解决方案的解决方案，但只需要上下文和图像文件作为输入

public static Bitmap rectifyImage(Context context,File imageFile){
    Bitmap originalBitmap= BitmapFactory.decodeFile(imageFile.getAbsolutePath());
    try{
        Uri uri=Uri.fromFile(imageFile);
        InputStream input = context.getContentResolver().openInputStream(uri);
        ExifInterface ei;
        
        if (Build.VERSION.SDK_INT > 23)
            ei = new ExifInterface(input);
        else
            ei = new ExifInterface(uri.getPath());

        int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
        switch (orientation) {
            case ExifInterface.ORIENTATION_ROTATE_90:
                return rotateImage(originalBitmap, 90);
            case ExifInterface.ORIENTATION_ROTATE_180:
                return rotateImage(originalBitmap, 180);
            case ExifInterface.ORIENTATION_ROTATE_270:
                return rotateImage(originalBitmap, 270);
            default:
                return originalBitmap;
        }
    }catch (Exception e){
        return originalBitmap;
    }
}

public static Bitmap rotateImage(Bitmap source, float angle) {
    Matrix matrix = new Matrix();
    matrix.postRotate(angle);
    return Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(),
            matrix, true);
}