Android get Orientation of a camera Bitmap? And rotate back -90 degrees

Question

I have this code: ``` //choosed a picture public void onActivityResult(int requestCode, int resultCode, Intent data) { if (resultCode == RESULT_OK) { if (requestCode == ImageHelper.SELECT_PICTURE) { String picture = ""; Uri selectedImageUri = data.getData(); //OI FILE Manager String filemanagerstring = selectedImageUri.getPath(); //MEDIA GALLERY String selectedImagePath = ImageHelper.getPath(mycontext, selectedImageUri); picture=(selectedImagePath!=null)?selectedImagePath:filemanagerstring; ``` ... This is only a picture chooser, from gallery. This is nice, but when I open this picture on an ImageView, the images when took on "PORTRAIT MODE" with the camera look nice, but the images that took "LANDSCAPE MODE" with the camera, opening in -90 degrees. How can i rotate those pictures back? ``` Bitmap output = Bitmap.createBitmap(newwidth, newheight, Config.ARGB_8888); Canvas canvas = new Canvas(output); ``` I tried this: ``` Log.e("w h", bitmap.getWidth()+" "+bitmap.getHeight()); if (bit…

Accepted Answer

If a photo is taken with a digital camera or smartphone, rotation is often stored in the photo's Exif data, as part of the image file. You can read an image's Exif meta-data using the Android `ExifInterface`.

First, create the `ExifInterface`:

```
ExifInterface exif = new ExifInterface(uri.getPath());
```

Next, find the current rotation:

```
int rotation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);  
```

Convert exif rotation to degrees:

```
int rotationInDegrees = exifToDegrees(rotation);
```

where

```
private static int exifToDegrees(int exifOrientation) {        
    if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_90) { return 90; } 
    else if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_180) {  return 180; } 
    else if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_270) {  return 270; }            
    return 0;    
 }
```

Then use the image's actual rotation as a reference point to rotate the image using a `Matrix`.

```
Matrix matrix = new Matrix();
if (rotation != 0) {matrix.preRotate(rotationInDegrees);}
```

You create the new rotated image with the `Bitmap.createBitmap` method that take a `Matrix` as a parameter:

```
Bitmap.createBitmap(Bitmap source, int x, int y, int width, int height, Matrix m, boolean filter)
```

where `Matrix m` holds the new rotation:

```
Bitmap adjustedBitmap = Bitmap.createBitmap(sourceBitmap, 0, 0, width, height, matrix, true);
```

See this tutorial for a useful source code example:

- Read Exif information in a JPEG file.

Android get Orientation of a camera Bitmap? And rotate back -90 degrees

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