为什么使用相机意图捕获的图像会在 Android 上的某些设备上旋转? [英] Why does an image captured using camera intent gets rotated on some devices on Android?

问题描述

我正在捕捉图像并将其设置为图像视图.

I'm capturing an image and setting it to image view.

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，某些设备上的图像每次旋转时都会出现.例如，在三星设备上效果很好，但在 Sony Xperia 上，图像会旋转 90 度，而在 Sony Xperiaa href="https://en.wikipedia.org/wiki/Toshiba_Thrive">Toshiba Thrive(平板电脑)180 度.

But the problem is, the image on some devices every time it gets rotated. For example, on a Samsung device it works good, but on a Sony Xperia the image gets rotated by 90 degrees and on Toshiba Thrive (tablet) by 180 degrees.

推荐答案

大多数手机摄像头都是横向的，这意味着如果您以纵向拍摄照片，生成的照片将旋转 90 度.在这种情况下，相机软件应使用应查看照片的方向填充 Exif 数据在.

Most phone cameras are landscape, meaning if you take the photo in portrait, the resulting photos will be rotated 90 degrees. In this case, the camera software should populate the Exif data with the orientation that the photo should be viewed in.

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工作，但它不是 100% 可靠的解决方案.

Note that the below solution depends on the camera software/device manufacturer populating the Exif data, so it will work in most cases, but it is not a 100% reliable solution.

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;
}

这里是 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);
}

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