Android Extract EXIF metadata from byte[] data
android, android-camera, exif, metadata
Solution
Please try the code snippet below, and change it where you need to. Warning: I haven't tested it.
So, basically, what I did is this:
- Step 1. Get the byte array from the camera in the onPictureTaken method.
- Step 2. Create a file on the SDCard and write the byte array to the file
Step 3. Read Exif Metadata from File-Path
@Override
public void onPictureTaken(byte[] data, Camera camera) {
//Step 1. Create file for storing image data on SDCard
File sdDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File pictureFileDir = new File(sdDir, "RDCCameraImages");
if (!pictureFileDir.exists() && !pictureFileDir.mkdirs()) {
Log.d(TAG, "Can't create directory to save image.");
return;
}
//Step 2. write image byte array to file
String photoFile = "Picture_" + date + ".jpg";
String imageFilePath = pictureFileDir.getPath() + File.separator + photoFile;
File pictureFile = new File(imageFilePath);
try
{
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
Toast.makeText(context, "New Image saved:" + photoFile,
Toast.LENGTH_LONG).show();
} catch (Exception error) {
Log.d(TAG, "File" + filename + "not saved: "
+ error.getMessage());
Toast.makeText(context, "Image could not be saved.",
Toast.LENGTH_LONG).show();
}
//Step 3. Get Exif Info from File path
ExifInterface exif;
try {
exif = new ExifInterface(imageFilePath);
String make = exif.getAttribute(ExifInterface.TAG_MAKE);
} catch (IOException e) {
e.printStackTrace();
}
//check the value of “make” here
}
Problem
I have a custom camera application. I need metadata of Image captured by the custom camera. I saved the byte data before decodebytearray (Constant.imageData1 = data;) and save it to a constant class with type byte and before using this byte data I converted it to string. When I going to execute it with ExifInterface and show it to log, then the application crashes. Here is my OnPictureTaken Method: ``` PictureCallback mPicture = new PictureCallback() { @Override public void onPictureTaken(byte[] data, Camera camera) { Constant.imageData1 = data; Log.e("Camrera", "22222222222222222"); BitmapFactory.Options bfo = new BitmapFactory.Options(); bfo.inDither = false; // bfo.inJustDecodeBounds = true; bfo.inPurgeable = true; bfo.inTempStorage = new byte[16 * 1024]; Intent intent = new Intent(context, PreviewActivity.class); // intent.putExtra("data", data); Bitmap bitmapPicture = BitmapFactory.decodeByteArray(data, 0, data.length, bfo); Matrix matrix = new Matrix(); if (Constant.result == 180) { matrix.postRotate(270); } if (Constant.result == 270) { matrix.postRotate(180); } int height = bitmapPicture.getHeight(); int width = bitmapPicture.getWidth(); //Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmapPicture, //height, width, true); Bitmap rotatedBitmap = Bitmap.createBitmap(bitmapPicture, 0, 0, bitmapPicture.getWidth(), bitmapPicture.getHeight(), matrix, true); ByteArrayOutputStream blob = new ByteArrayOutputStream(); Log.e("Camrera1", "22222222222222222"); rotatedBitmap.compress(CompressFormat.JPEG, 50 /* ignored for PNG */, blob); byte[] bitmapdata = blob.toByteArray(); Constant.imageData = bitmapdata; Log.e("Camrera2", "22222222222222222"); startActivity(intent); } }; ``` Here is my execution code: ``` private void SaveImage() { try { String data = byteArrayToString(Constant.imageData1); ExifInterface ex = new ExifInterface(data); String make = ex.getAttribute(ExifInterface.TAG_MAKE); Log.e("Make", make); Log.e("Make", make); Log.e("Make", make); finish(); } catch (Exception e) { e.printStackTrace(); } } ``` And the bytearraytostring method is: ``` public static String byteArrayToString(byte[] bytes) { return new String(bytes); } ``` This is very important to me. Please help me.