code: def get_relative_path_from_img_id(img_id, variant_label=None, ext=None, create_dirs=False):
      
      profile, base_name = img_id.split(':', 1)
      conf = get_profile_configs(profile)
      if not variant_label:
          status_suffix = dju_settings.DJU_IMG_UPLOAD_MAIN_SUFFIX
      else:
          status_suffix = dju_settings.DJU_IMG_UPLOAD_VARIANT_SUFFIX
      name, file_ext = os.path.splitext(base_name)
      prefix = ''
      if name.startswith(dju_settings.DJU_IMG_UPLOAD_TMP_PREFIX):
          name = name[len(dju_settings.DJU_IMG_UPLOAD_TMP_PREFIX):]
          prefix = dju_settings.DJU_IMG_UPLOAD_TMP_PREFIX
      name_parts = name.split('_', 2)
      name = '{name}{status_suffix}{hash}'.format(
          name=name,
          status_suffix=status_suffix,
          hash=get_hash('_'.join(name_parts[:2]), variant_label=variant_label)
      )
      if variant_label:
          name += '_' + variant_label
      if ext:
          file_ext = ext
      elif variant_label:
          for var_conf in conf['VARIANTS']:
              var_conf_label = var_conf['LABEL'] or get_variant_label(var_conf)
              if var_conf_label == variant_label:
                  if var_conf['FORMAT']:
                      file_ext = var_conf['FORMAT'].lower()
                  break
      if file_ext and not file_ext.startswith('.'):
          file_ext = '.' + file_ext
      relative_path = os.path.join(
          dju_settings.DJU_IMG_UPLOAD_SUBDIR,
          conf['PATH'],
          name_parts[0][-2:],
          (prefix + name + file_ext)
      ).replace('\\', '/')
      if create_dirs:
          path = media_path(relative_path)
          make_dirs_for_file_path(path, mode=dju_settings.DJU_IMG_CHMOD_DIR)
      return relative_path
docs: Returns path to file relative MEDIA_URL.