code: private boolean isImageType(String mime) {
  		if (StringUtils.hasText(mime)) {
  			for (String imageMime : IMAGE_MIMES) {
  				if (mime.equalsIgnoreCase(imageMime)) {
  					return true;
  				}
  			}
  		}
  		return false;
  	}
docs: Method to validate whether the given mime is an image file
  
  @param mime the mime type
  @return boolean returns true if the file is image