How to avoid gzip on php resized images

apache-2.2gzip

We should not gzip images, right? How do I avoid gzipping on images like this: img/sample.php?id=image_name.jpg can also be called like this img/sample.php?id=image_name.jpg&size=3 the actual images live here /images/items/

I tried using 2 types of configuration for gzip in httpd.conf (see below), but in both cases the images were gzipped anyway.

Images are obviously not being treated like a regular .jpg file, because if it was it would not have been gzipped with any of the below configurations. However live headers shows it as a regular image/jpeg

Any idea how to fix this?

1st try:

<Location />
# Insert filter
SetOutputFilter DEFLATE

# Netscape 4.x has some problems...
<Location />
# Insert filter
SetOutputFilter DEFLATE

# Netscape 4.x has some problems...
BrowserMatch ^Mozilla/4 gzip-only-text/html

# Netscape 4.06-4.08 have some more problems
BrowserMatch ^Mozilla/4\.0[678] no-gzip

# MSIE masquerades as Netscape, but it is fine
# BrowserMatch \bMSIE !no-gzip !gzip-only-text/html

# NOTE: Due to a bug in mod_setenvif up to Apache 2.0.48
# the above regex won't work. You can use the following
# workaround to get the desired effect:
BrowserMatch \bMSI[E] !no-gzip !gzip-only-text/html

# Don't compress images
SetEnvIfNoCase Request_URI \
\.(?:gif|jpe?g|png)$ no-gzip dont-vary

# Make sure proxies don't deliver the wrong content
Header append Vary User-Agent env=!dont-vary
</Location>BrowserMatch ^Mozilla/4 gzip-only-text/html

# Netscape 4.06-4.08 have some more problems
BrowserMatch ^Mozilla/4\.0[678] no-gzip

# MSIE masquerades as Netscape, but it is fine
# BrowserMatch \bMSIE !no-gzip !gzip-only-text/html

# NOTE: Due to a bug in mod_setenvif up to Apache 2.0.48
# the above regex won't work. You can use the following
# workaround to get the desired effect:
BrowserMatch \bMSI[E] !no-gzip !gzip-only-text/html

# Don't compress images
SetEnvIfNoCase Request_URI \
\.(?:gif|jpe?g|png)$ no-gzip dont-vary

# Make sure proxies don't deliver the wrong content
Header append Vary User-Agent env=!dont-vary
</Location>

2nd try:

    <IfModule mod_deflate.c>
AddOutputFilterByType DEFLATE text/plain    
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE text/xml    
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE text/javascript
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/x-javascript
AddOutputFilterByType DEFLATE application/json
</IfModule>

Best Answer

This part:

# Don't compress images
SetEnvIfNoCase Request_URI \
\.(?:gif|jpe?g|png)$ no-gzip dont-vary

Is looking for image file extensions in the request URI. Your file extensions are in the query string.

Unfortunately, mod_setenvif doesn't have access to the query string and if I am reading the documentation correctly, neither does LocationMatch.

mod_rewrite, however, does have access to the query string and can set environment variables.

RewriteCond %{QUERY_STRING} \.(?:gif|jpe?g|png)$
RewriteRule ^ - [E=no-gzip,dont-vary]

If you're using mod_rewrite anyway, it might be a better idea to use it to rewrite the URLs so that they don't have a query string at all. The following makes the above two lines unnecessary.

RewriteRule /generated_images/(.*\.(?:gif|jpe?g|png))$ /sample.php?id=$1

Related Solutions

Gzip to bmp images on the fly

If possible, use PNG as image format. It's the defacto standard for lossless image compression and will probably surpass the compression level achieved by merely gziping bitmaps.

If you need to use BMP because of dependencies from legacy systems, you can try using the output compression methods available in your webserver, e.g. see mod_deflate for Apache. Wireshark can be especially helpful in testing/debugging such setups.

Windows – Content Encoding Error when trying to use GZip on Apache

The first issue is that you have the element with a directory from the file system...

This is from the Apache manual:

When to use <Location>. Use <Location> to apply directives to content that lives outside the filesystem. For content that lives in the filesystem, use <Directory> and <Files>. An exception is <Location />, which is an easy way to apply a configuration to the entire server.

When I setup mod_deflate on Apache I use this setup:

# --------------------------------------------------------
# Deflate Module Configuration
# --------------------------------------------------------
<IfModule deflate_module>
  # Set the location to webservers root
  <Location />
    # Insert the filters
    SetOutputFilter DEFLATE

    # Netscape 4.x has some problems
    BrowserMatch ^Mozilla/4 gzip-only-text/html
    # Netscape 4.06-4.08 have some more problems
    BrowserMatch ^Mozilla/4.0[678] no-gzip
    # MSIE masquerades as Netscape, but it is fine
    BrowserMatch \bMSIE !no-gzip !gzip-only-text/html

    # Make sure proxies don't deliver the wrong content
    Header append Vary User-Agent env=!dont-vary

    # Make sure to never zip binaries (ie6 and chrome has issues with this.)
    SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary
    SetEnvIfNoCase Request_URI \.(?:exe|t?gz|zip|bz2|sit|rar)$ no-gzip dont-vary
    SetEnvIfNoCase Request_URI \.pdf$ no-gzip dont-vary
  </Location>

    # Enable mod_deflate logging by uncommenting these lines
    #DeflateFilterNote Input instream
    #DeflateFilterNote Output outstream
    #DeflateFilterNote Ratio ratio

    #LogFormat '"%r" %{outstream}n/%{instream}n (%{ratio}n%%)' deflate
    #CustomLog logs/deflate_log deflate 
</IfModule>

Best Answer

Related Solutions

Gzip to bmp images on the fly

Windows – Content Encoding Error when trying to use GZip on Apache

Related Topic