Как правильно оптимизировать изображения под Google Page Speed?

<IfModule pagespeed_module> 
    ModPagespeed on
    AddOutputFilterByType MOD_PAGESPEED_OUTPUT_FILTER text/html
    ModPagespeedFileCachePath            "/var/cache/mod_pagespeed/"
    ModPagespeedLogDir "/var/log/pagespeed"
    ModPagespeedSslCertDirectory "/etc/ssl/certs"
     ModPagespeedMemcachedServers localhost:11211
       ModPagespeedDomain static.my-site.ru
     ModPagespeedFileCacheInodeLimit        500000
      ModPagespeedImageRecompressionQuality 70
     ModPagespeedJpegRecompressionQuality 70
     ModPagespeedJpegRecompressionQualityForSmallScreens 70
     ModPagespeedWebpRecompressionQuality 70
     ModPagespeedWebpRecompressionQualityForSmallScreens 70
    <Location /pagespeed_admin>
        Order allow,deny
        Allow from localhost
        Allow from 127.0.0.1
        SetHandler pagespeed_admin
    </Location>
    <Location /pagespeed_global_admin>
        Order allow,deny
        Allow from localhost
        Allow from 127.0.0.1
        SetHandler pagespeed_global_admin
    </Location>
    ModPagespeedStatisticsLogging on
    ModPagespeedMessageBufferSize 100000
</IfModule>