How to avoid 404 for images in access log?

[Alexandr Gomoliako]

On 9/22/11, etrader <nginx-forum at nginx.us> wrote:
> My access log is full of 404 logs for images not found; thus, it is
> difficult to find real 200 successful visits. The lines include
>
> ... GET /css/img/calendar.png HTTP/1.1"  404 31
> "http://mydomain.com.page.html ...

Try something like
    cat access.log | grep " 200 "