Reported response time for Web pages with PNG images does not match actual load time
The problem: When you are measuring response time for loading web pages with PNG images, you might notice that the actual time to load the web pages takes longer than the reported response time, and PNG images are treated as separate transactions instead of being included in the response time of the web pages that contain these PNG images.
The solution: This problem can occur if the web server that is serving the PNG file for the application is configured to serve PNG image files with a Content-Type: header of text/plain instead of image/png. This causes the Web Response Time agent to treat the PNG image file as a transaction rather than a page element.
To resolve this problem, check your web server configuration and
ensure that it is configured to serve PNG image files with a Content-Type:
header of image/png. For the IBM HTTP Server, ensure that the
configuration file mime.types contains the following line:
image/png png