Inline Preview Images

[Hemant Nandrajog]

Hello, 

Is there any setting which is required to make this inline_preview_images work?

http://mastposters.com/avril-lavigne/avril-lavigne-still-from-a-stage-performance-with-a-mic-in-hand/?ModPagespeedFilters=+inline_preview_images

Tried loading the above page quite few times 

but no image comes up with pagespeed_high_res_src  in the source

IndexNum or MinBytes are not included in the configuration or the site so assuming they will be at default values 

Thanks,

Hemant 

[Jud Porter]

Hi Hemant,

Thanks for the report. It looks like there are a few factors conspiring to make inline_preview_images not work well on that page.

First off, the critical image beaconing feature likely won't perfectly on this site due to the rotating Recent Wallpapers section. If you disable ModPagespeedCriticalImagesBeaconEnabled, you should see some of those images being inlined. When ModPagespeedCriticalImagesBeaconEnabled is enabled, inline_preview_images will only generate previews for the images it has detected as critical, and that are within the first MaxInlinedPreviewImagesIndex images on the site (default 5). In this case, that isn't going to work well because the first 5 images are in the recent wallpapers section and have not been identified as critical, so nothing will be inlined.

One thing you could try is leaving ModPagespeedCriticalImagesBeaconEnabled and tweaking those MaxInlinedPreviewImagesIndex and MinImagesSizeLowresolutionsBytes options to get better behavior by default. For example, if you set those options to something like 'ModPagespeedMaxInlinedPreviewImagesIndex -1' and 'ModPagespeedMinImageSizeLowResolutionBytes 15000' it should generate a preview image for just the large main image on the page.

Overall though, I think we can improve a couple things in that filter on our side. First, we should probably ignore the MaxInlinedPreviewImagesIndex option when critical image beaconing is enabled. This option is really a proxy for indicating how many critical images you expect on the page, and as in your case, can cause unexpected behavior when both are enabled. We also need to come up with a better solution for the case of the random rotating images like you have on your site, likely by being smarter about when and how often we instrument a page.

-Jud

[Hemant Nandrajog]

Hello Jud, 

The random wallpapers/photos block really helps in generating more pageviews and keep user interested in browsing site more so I use those blocks on many of my sites.

What I will suggest is having an option where a certain block of code/html can be ignored by pagespeed example I can put that box in div with attribute pagespeedignore=inline_images,lazyload_images

And I tested with your recommended settings for ModPagespeedMaxInlinedPreviewImagesIndex and ModPagespeedMinImageSizeLowResolutionBytes and I can see low resolution one for a flash of a second, I will try it with some low speed connections and see how helpful it actually is 

Thanks