I use below code to save bitmap image (captured from layout) to android default picture directory. It seems that the saved image is corrupt because Gallery can not open this.
When I save the bitmap in another location the gallery can open it. but it is not opening when I save it to the android default directory.
   public void saveToGallery() {
        String path = Environment.getExternalStorageDirectory().toString()
                + "/Pictures/Keshavarzi/" + "screenshot-" + System.currentTimeMillis() + ".png";
        ViewGroup v = (ViewGroup) findViewById(R.id.lyt_main_report_activity);
        v.setDrawingCacheEnabled(true);
        v.setDrawingCacheEnabled(true);
        v.buildDrawingCache();
        Bitmap bitmap = Bitmap.createBitmap(v.getDrawingCache());
        v.setDrawingCacheEnabled(false);
        OutputStream out = null;
        File imageFile = new File(path);
        try {
            out = new FileOutputStream(imageFile);
            bitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
            out.flush();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
            } catch (Exception exc) {
            }
        }
        ContentValues values = new ContentValues();
        values.put(MediaStore.Images.Media.TITLE, "Title");
        values.put(MediaStore.Images.Media.DESCRIPTION, "Description");
        values.put(MediaStore.Images.Media.DATE_TAKEN, System.currentTimeMillis());
        values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
        values.put(MediaStore.MediaColumns.DATA, path);
        getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
        MHToast.showToast(getString(R.string.saved_in_gallery), Toast.LENGTH_LONG);
    }
 
                        
try this, check if your save directory is exists or create directory first then save bitmap,