My site is basically an image host service. The user calls the image via /sig/<id>.png, which is redirected to /sig.php?id=<id> via mod_rewrite:
The path the user calls the image from is the true path. They are redirected through the sig.php file to log the image hit.
RewriteRule ^sig/(.*).png /sig.php?id=$1
When a image does not exist (checked with file_exists()), it looks like the mod_rewrite still redirects, but a 404 is added to my error log - not error_log, but the true log file. In the sig.php file the image is only called if the file exists, if it does not an 'error image' is sent to the browser.
Is it possible to not log 404 errors from missing signatures? Its hard to find the real website errors because they are covered up by these 404 image errors. --- better idea: Can I turn off error logging for a specific directory?