Android image resizing and preserving EXIF data (orientation, rotation, etc.)

androidandroid-cameraexifimage

If your Android app uses the device camera to take a picture and then resizes it (this is very, very common to reduce the size for upload), you might not realize that this resize operation strips the Exif metadata.

This can cause problems, especially if the device in question relies on the 'Orientation' tag to properly show the image upright.

Different Android devices handle camera/image rotation in different ways – my trusty old Nexus One seems to always rotate the image immediately post capture, so the file's native contents are always 'upright' when viewed.

However, other devices (especially Samsung phones in my testing), do not rotate the contents of the image file – rather, they set the Exif 'Orientation' tag. Whenever the image is displayed later, the relevant image code should detect the presence of the Orientation 'tag' and rotate the image appropriately. But if you have done any bitmap processing on the image and saved it to a new file, all of that Exif data is lost.

In addition to Orientation data, you might also lose other valuable metadata such as make/model, etc.

This confused me for a few weeks (image appears upright when displayed in phone gallery, but then arrives on my server with bad orientation and no apparent metadata). I'm adding this self-question here to help others. This blog post was very helpful:

Android re-size image without loosing EXIF information

Best Answer

As far as I can tell, there is no mechanism to persist the metadata automatically or even snapshot whatever is there and transfer in bulk.

Rather, it seems you must explicitly check for specific properties and copy them yourself to the new image file using the ExifInterface.

http://developer.android.com/reference/android/media/ExifInterface.html

So something like:

ExifInterface oldExif = new ExifInterface(oldImagePath);
String exifOrientation = oldExif.getAttribute(ExifInterface.TAG_ORIENTATION);

if (exifOrientation != null) {
   ExifInterface newExif = new ExifInterface(imagePath);
   newExif.setAttribute(ExifInterface.TAG_ORIENTATION, exifOrientation);
   newExif.saveAttributes();
}

Related Solutions

Android – EXIF orientation tag value always 0 for image taken with portrait camera app android

I also faced same issue in Samsung devices, later I implemented ExifInterface and solved successfully.

In any mode images will be shot it will always store in portrait mode only, and while fetching too returning in portrait mode. below of code I used to achieve my goal, I implemented within back camera, not sure about from camera.

Camera Intent@

Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
            intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
            startActivityForResult(intent, 1212);

onActivityResult@

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

        if (requestCode == 1212) {
        sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"+ Environment.getExternalStorageDirectory())));
        Bitmap bitmap;
        //bitmap=GlobalMethods.decodeSampledBitmapFromResource(_path, 80, 80);
        bitmap=GlobalMethods.decodeFile(_path);
        if (bitmap == null) {
            imgMed.setImageBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.add_photo));
        } 
        else {
            imgMed.setImageBitmap(bitmap);
            imgMed.setScaleType(ScaleType.FIT_XY);

        }
    }
        }

decodeFile@

    public static Bitmap decodeFile(String path) {

          int orientation;

             try {

                 if(path==null){

                     return null;
                 }
                 // decode image size
                 BitmapFactory.Options o = new BitmapFactory.Options();
                 o.inJustDecodeBounds = true;

                 // Find the correct scale value. It should be the power of 2.
                 final int REQUIRED_SIZE = 70;
                 int width_tmp = o.outWidth, height_tmp = o.outHeight;
                 int scale = 4;
                 while (true) {
                     if (width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 < REQUIRED_SIZE)
                         break;
                     width_tmp /= 2;
                     height_tmp /= 2;
                     scale++;
                 }
                 // decode with inSampleSize
                 BitmapFactory.Options o2 = new BitmapFactory.Options();
                 o2.inSampleSize=scale;
                 Bitmap bm = BitmapFactory.decodeFile(path,o2);


                 Bitmap bitmap = bm;

                 ExifInterface exif = new ExifInterface(path);
                 orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);
                 Log.e("orientation",""+orientation);
                 Matrix m=new Matrix();

                 if((orientation==3)){

                 m.postRotate(180);
                 m.postScale((float)bm.getWidth(), (float)bm.getHeight());

//               if(m.preRotate(90)){
                 Log.e("in orientation",""+orientation);

                 bitmap = Bitmap.createBitmap(bm, 0, 0,bm.getWidth(),bm.getHeight(), m, true);
                 return  bitmap;
                 }
                 else if(orientation==6){

                  m.postRotate(90);

                  Log.e("in orientation",""+orientation);

                  bitmap = Bitmap.createBitmap(bm, 0, 0,bm.getWidth(),bm.getHeight(), m, true);
                     return  bitmap;
                 }

                 else if(orientation==8){

                  m.postRotate(270);

                  Log.e("in orientation",""+orientation);

                  bitmap = Bitmap.createBitmap(bm, 0, 0,bm.getWidth(),bm.getHeight(), m, true);
                     return  bitmap;
                 }
                 return bitmap;
             }
             catch (Exception e) {
             }
             return null;
         }

R – Can’t switch language environment in Django

According to the django docs

http://docs.djangoproject.com/en/dev/topics/i18n/#id2

LocaleMiddleware tries to determine the user's language preference by following this algorithm:

* First, it looks for a django_language key in the current user's session.

* Failing that, it looks for a cookie.

[...]

*Failing that, it looks at the Accept-Language HTTP header. This header is sent by your browser and tells the server which language(s) you prefer, in order by priority. Django > tries each language in the header  until it finds one with available translations.

* Failing that, it uses the global LANGUAGE_CODE setting.

If you only need one language, 'es', you can disable the middleware. If you really need LocaleMiddleware active, try this recipe to override the headers from the client's browser http://www.djangosnippets.org/snippets/218/:

enter code here

class ForceDefaultLanguageMiddleware(object):
    """
    Ignore Accept-Language HTTP headers

    This will force the I18N machinery to always choose settings.LANGUAGE_CODE
    as the default initial language, unless another one is set via sessions or cookies

    Should be installed *before* any middleware that checks    request.META['HTTP_ACCEPT_LANGUAGE'],
    namely django.middleware.locale.LocaleMiddleware
    """
    def process_request(self, request):
        if request.META.has_key('HTTP_ACCEPT_LANGUAGE'):
            del request.META['HTTP_ACCEPT_LANGUAGE']

Best Answer

Related Solutions

Android – EXIF orientation tag value always 0 for image taken with portrait camera app android

R – Can’t switch language environment in Django

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