code: protected String rewriteURL(String url, String binaryServletPath, String newCssPath,
  			BinaryResourcesHandler binaryRsHandler) throws IOException {
  
  		String imgUrl = url;
  		if (isBinaryResource(imgUrl)) {
  			imgUrl = addCacheBuster(url, binaryRsHandler);
  			// Add image servlet path in the URL, if it's defined
  			if (StringUtils.isNotEmpty(binaryServletPath)) {
  				imgUrl = binaryServletPath + JawrConstant.URL_SEPARATOR + imgUrl;
  			}
  		}
  
  		imgUrl = PathNormalizer.asPath(imgUrl);
  		return PathNormalizer.getRelativeWebPath(PathNormalizer.getParentPath(newCssPath), imgUrl);
  	}
docs: Rewrites the image URL
  
  @param url
  the image URL
  @param binaryServletPath
  the binary servlet path
  @param newCssPath
  the new Css path
  @param binaryRsHandler
  the image resource handler
  @return the rewritten image URL
  @throws IOException
  if an IOException occurs