public static File getFileForOfflineLogImage(final String imageFileName) {
        //extract geocode
        String geocode = null;
        if (imageFileName.startsWith(OFFLINE_LOG_IMAGE_PREFIX)) {
            final int idx = imageFileName.indexOf("-", OFFLINE_LOG_IMAGE_PREFIX.length());
            if (idx >= 0) {
                geocode = imageFileName.substring(OFFLINE_LOG_IMAGE_PREFIX.length(), idx);
            }
        }
        return new File(LocalStorage.getOfflineLogImageDir(geocode), imageFileName);
    }
Creates a new image Uri for a public image.
Just the filename and uri is created, no data is stored.

@param geocode an identifier which will become part of the filename. Might be e.g. the gccode
@return left: created filename, right: uri for the image
main/src/main/java/cgeo/geocaching/utils/ImageUtils.java