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> In medium to high BPP photographic images (which, I believe, is the most common use of lossy image compression) I don't think this is true. Most web images s

> In medium to high BPP photographic images (which, I believe, is the most common use of lossy image compression) I don't think this is true. Most web images shouldn't be "near lossless" they should be "not ugly", with the exception being images that are core content (think Flickr or Unsplash). If a tech product is illustrated with a child laughing at some salad, or whatever, it doesn't matter if some detail is lost, as long as it doesn't look ugly-compressed. Users will be scrolling past it, not zooming in and comparing it to the original. I did a performance analysis of a set of sites recently, and many have images that are 10x bigger than necessary https://jakearchibald.com/2021/f1-perf-part-2/#issue-large-primary-image https://jakearchibald.com/2021/f1-perf-part-2/#issue-large-p....

ehnto 5y ago
I mostly agree, with the caveat that a great deal of web traffic is now image sharing social sites and so any reduction in traffic size is still a good thing. I also want to point out that people can tell the difference between when something should be good quality and when it doesn't matter. Like even on Instagram, people will forgive a pixelated meme but still be disappointed by a portrait with compression artifacts.
- jaffathecake 5y ago
  In my experience, folks are referring to blocky JPEG compression in those cases. Or, for digital art, specifically chroma subsampling. I can't decide if Instagram falls under the like-Flickr use-case or not. I think on mobile, AVIF-style compression would still be best, but it could be different on desktop.
ksec 5y ago
There was a paper with stats from Google Chrome, with over a billion of image sampled, saying 90%+ of image on the web has BPP over 1.0. And the median of image BPP is between 2.0 to 3.0 depending on image dimensions. I keep swinging from one side to another, on one hand I want image size to be much smaller ( HEIF / AVIF or better yet, something based on VVC ) BPP 0.1+, on the other hand a 500x500 image is only 32KB at BPP 1.0 with JPEGXL. Right now I am mostly alining to JPEGXL because I think AVIF or others Ultra Low BitRate format are sort of over optimising, not to mention JPEGXL decode faster and uses less resources. So it seems to be the most practical one.
TeMPOraL 5y ago
> I don't think this is true. Most web images shouldn't be "near lossless" they should be "not ugly", with the exception being images that are core content (think Flickr or Unsplash). Hard disagree here. We're talking image format, not image renderers. Whatever ends up being standardized on will eventually become the format "core content" is being stored in and transferred in. It will be the format in which my phone will save photos of my daughter, the format that her grandparents will receive those photos in (possibly twice transcoded by whatever IM they're using these days), so believe me, "not ugly" isn't gonna cut it here. The photographers, the stock photo sites, the marketers - they'll all know how to keep images at high quality, and they have their reasons for doing so. Regular people will typically just use the defaults, so it's important to optimize the defaults for them, instead of marketing spam. If marketing spam is indeed the majority of data traffic on-line, there are other avenues to address it. > I did a performance analysis of a set of sites recently, and many have images that are 10x bigger than necessary Yeah, they also don't care. Why would they? Bandwidth is usually too cheap to meter for most commercial sites like these. If we try to fix their image sizes top-down by more aggressive quality reduction, some marketer will eventually notice the images "look bad", and fix it. Meanwhile, regular people will get the short end of the stick.
- jaffathecake 5y ago
  Phones are already using different formats for image storage. Apps are already sending those at different qualities and formats when you share them. You shouldn't just take an image from your phone as-is, stick it on a website, and display it at 400x400 or whatever. Firstly, that won't work if you took the image with an iPhone, since it uses HEIF, which isn't supported by any browser. Secondly, it'll be orders of magnitude too big. Sites will care about this stuff when it impacts their metrics like first-contentful-paint, which will soon begin impacting Google search ranking.
- crazygringo 5y ago
  > Yeah, they also don't care. Why would they? Bandwidth is usually too cheap to meter for most commercial sites like these. Because it's not about server bandwidth, it's about download speeds on slow connections -- mobile, bad Wi-Fi, etc. You always want images that are no larger than they have to be for page load speeds. It's a user experience thing, not a cost thing.
account42 5y ago
> If a tech product is illustrated with a child laughing at some salad, or whatever, it doesn't matter if some detail is lost, as long as it doesn't look ugly-compressed. Users will be scrolling past it, not zooming in and comparing it to the original. In that case the best compression is to omit the image.
lucideer 5y ago
> with the exception being images that are core content This is not the exception. This is the common case. Instagram/Facebook posts, Tweets (a very large % have images now), TikTok/Youtube/Twitch/Netflix thumbnails, people sending photos of their family/dog/cat/houseplant to a WhatsApp/Telegram group: all of these are transferred in compressed formats. That's even before you get into the debate of whether photojournalists' images on news articles (FAR more common than product pics on tech sites) fall under your definition of "images users scroll past", or "core content". It seems pretty bizarre to think 10 F1 websites are representative of the common cases.
- crazygringo 5y ago
  I wouldn't call those core content that needs to be maximum quality. They're normal content that needs to be non-ugly. The examples given of core content were Flickr and Unsplash. In other words, photographic perfection. Photographic perfection-quality on the web is definitely the exception, not the rule.

ehnto 5y ago

I mostly agree, with the caveat that a great deal of web traffic is now image sharing social sites and so any reduction in traffic size is still a good thing. I also want to point out that people can tell the difference between when something should be good quality and when it doesn't matter. Like even on Instagram, people will forgive a pixelated meme but still be disappointed by a portrait with compression artifacts.

jaffathecake 5y ago
In my experience, folks are referring to blocky JPEG compression in those cases. Or, for digital art, specifically chroma subsampling. I can't decide if Instagram falls under the like-Flickr use-case or not. I think on mobile, AVIF-style compression would still be best, but it could be different on desktop.

ksec 5y ago

There was a paper with stats from Google Chrome, with over a billion of image sampled, saying 90%+ of image on the web has BPP over 1.0. And the median of image BPP is between 2.0 to 3.0 depending on image dimensions. I keep swinging from one side to another, on one hand I want image size to be much smaller ( HEIF / AVIF or better yet, something based on VVC ) BPP 0.1+, on the other hand a 500x500 image is only 32KB at BPP 1.0 with JPEGXL. Right now I am mostly alining to JPEGXL because I think AVIF or others Ultra Low BitRate format are sort of over optimising, not to mention JPEGXL decode faster and uses less resources. So it seems to be the most practical one.

TeMPOraL 5y ago

> I don't think this is true. Most web images shouldn't be "near lossless" they should be "not ugly", with the exception being images that are core content (think Flickr or Unsplash). Hard disagree here. We're talking image format, not image renderers. Whatever ends up being standardized on will eventually become the format "core content" is being stored in and transferred in. It will be the format in which my phone will save photos of my daughter, the format that her grandparents will receive those photos in (possibly twice transcoded by whatever IM they're using these days), so believe me, "not ugly" isn't gonna cut it here. The photographers, the stock photo sites, the marketers - they'll all know how to keep images at high quality, and they have their reasons for doing so. Regular people will typically just use the defaults, so it's important to optimize the defaults for them, instead of marketing spam. If marketing spam is indeed the majority of data traffic on-line, there are other avenues to address it. > I did a performance analysis of a set of sites recently, and many have images that are 10x bigger than necessary Yeah, they also don't care. Why would they? Bandwidth is usually too cheap to meter for most commercial sites like these. If we try to fix their image sizes top-down by more aggressive quality reduction, some marketer will eventually notice the images "look bad", and fix it. Meanwhile, regular people will get the short end of the stick.

jaffathecake 5y ago
Phones are already using different formats for image storage. Apps are already sending those at different qualities and formats when you share them. You shouldn't just take an image from your phone as-is, stick it on a website, and display it at 400x400 or whatever. Firstly, that won't work if you took the image with an iPhone, since it uses HEIF, which isn't supported by any browser. Secondly, it'll be orders of magnitude too big. Sites will care about this stuff when it impacts their metrics like first-contentful-paint, which will soon begin impacting Google search ranking.
crazygringo 5y ago
> Yeah, they also don't care. Why would they? Bandwidth is usually too cheap to meter for most commercial sites like these. Because it's not about server bandwidth, it's about download speeds on slow connections -- mobile, bad Wi-Fi, etc. You always want images that are no larger than they have to be for page load speeds. It's a user experience thing, not a cost thing.

account42 5y ago

> If a tech product is illustrated with a child laughing at some salad, or whatever, it doesn't matter if some detail is lost, as long as it doesn't look ugly-compressed. Users will be scrolling past it, not zooming in and comparing it to the original. In that case the best compression is to omit the image.

lucideer 5y ago

> with the exception being images that are core content This is not the exception. This is the common case. Instagram/Facebook posts, Tweets (a very large % have images now), TikTok/Youtube/Twitch/Netflix thumbnails, people sending photos of their family/dog/cat/houseplant to a WhatsApp/Telegram group: all of these are transferred in compressed formats. That's even before you get into the debate of whether photojournalists' images on news articles (FAR more common than product pics on tech sites) fall under your definition of "images users scroll past", or "core content". It seems pretty bizarre to think 10 F1 websites are representative of the common cases.

crazygringo 5y ago
I wouldn't call those core content that needs to be maximum quality. They're normal content that needs to be non-ugly. The examples given of core content were Flickr and Unsplash. In other words, photographic perfection. Photographic perfection-quality on the web is definitely the exception, not the rule.