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Convert Bitmap to File

Posted by: admin November 30, 2017 Leave a comment

Questions:

I understand that using BitmapFactory can convert a File to a Bitmap, but is there any way to convert a Bitmap image to a File?

Answers:

Try this:

bitmap.compress(Bitmap.CompressFormat.PNG, quality, outStream);

See this

Questions:
Answers:

Hope it will help u:

//create a file to write bitmap data
File f = new File(context.getCacheDir(), filename);
f.createNewFile();

//Convert bitmap to byte array
Bitmap bitmap = your bitmap;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bitmap.compress(CompressFormat.PNG, 0 /*ignored for PNG*/, bos);
byte[] bitmapdata = bos.toByteArray();

//write the bytes in file
FileOutputStream fos = new FileOutputStream(f);
fos.write(bitmapdata);
fos.flush();
fos.close();

Questions:
Answers:
File file = new File("path");
OutputStream os = new BufferedOutputStream(new FileOutputStream(file));
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
os.close();

Questions:
Answers:

Converting Bitmap to File needs to be done in background (NOT IN THE MAIN THREAD) it hangs the UI specially if the bitmap was large

File file;

public class fileFromBitmap extends AsyncTask<Void, Integer, String> {

    Context context;
    Bitmap bitmap;
    String path_external = Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg";

    public fileFromBitmap(Bitmap bitmap, Context context) {
        this.bitmap = bitmap;
        this.context= context;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        // before executing doInBackground
        // update your UI
        // exp; make progressbar visible
    }

    @Override
    protected String doInBackground(Void... params) {

        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
        file = new File(Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg");
        try {
            FileOutputStream fo = new FileOutputStream(file);
            fo.write(bytes.toByteArray());
            fo.flush();
            fo.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }


    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        // back to main thread after finishing doInBackground
        // update your UI or take action after
        // exp; make progressbar gone

         sendFile(file);

    }
}

Calling it

new fileFromBitmap(my_bitmap, getApplicationContext());

you MUST use the file in onPostExecute .

To change directory of file to be stored in cache
replace line :

 file = new File(Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg");

with :

file  = new File(context.getCacheDir(), "temporary_file.jpg");