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Show HN: Simple image resizing/optimization service

scaley.io

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Re: Show HN: Simple image resizing/optimization service

#31

Post by leni536 »

hoahluke wrote: post #28
leni536 wrote: post #18

My acid test for image scaling software: http://i.imgur.com/X9vKa2s.png https://i.scaley.io/png-256x128/i.imgur.com/X9vKa2s.png This means that you don't use a linear color space for blending colors. Sorry about the language, the image is not made by me [1]. [1] https://web.archive.org/web/20120904060524/http://www.4p8.co... edit: I see that your backend relies on libvips to do the resizing. I have no experience with…

I didn't think this would come up so quickly! This can actually be fixed with an undocumented option 'gamma'[1] I didn't include it in the website, admittedly because I didn't fully understand it, and I wanted to keep the service as simple as possible. Would it make sense for this to be the default? [1] https://i.scaley.io/png-gamma-256x128/i.imgur.com/X9vKa2s.pn...

Nice! I think it should be the default. Some software might treats as a compromise between correctness and cost (doing the rescaling in linear space is usually more costly). In my view it should be correctness first.

The ImageWorsener's website as an excellent reading material on image resizing and other transformations. ImageWorsener is a "correctness first" image resizing software.

http://entropymine.com/imageworsener/

Re: Show HN: Simple image resizing/optimization service

#32

Post by Arnt »

hoahluke wrote: post #28
leni536 wrote: post #18

My acid test for image scaling software: http://i.imgur.com/X9vKa2s.png https://i.scaley.io/png-256x128/i.imgur.com/X9vKa2s.png This means that you don't use a linear color space for blending colors. Sorry about the language, the image is not made by me [1]. [1] https://web.archive.org/web/20120904060524/http://www.4p8.co... edit: I see that your backend relies on libvips to do the resizing. I have no experience with…

I didn't think this would come up so quickly! This can actually be fixed with an undocumented option 'gamma'[1] I didn't include it in the website, admittedly because I didn't fully understand it, and I wanted to keep the service as simple as possible. Would it make sense for this to be the default? [1] https://i.scaley.io/png-gamma-256x128/i.imgur.com/X9vKa2s.pn...

Averaging two RGB numbers isn't at all similar to how the human eye averages two colours.

The colour experts have a variety of ways to do much better, almost any of them will give you much better results. Pick one and be done. Your undocumented -gamma- option is fine.

If you want the best option you should be prepared to invest a lot of time and attention, in return for which you'll get a result that's perhaps a little better than your -gamma- and a lot better than plain RGB averaging.

Re: Show HN: Simple image resizing/optimization service

#33

Post by throwaway2016a »

leni536 wrote: post #18

My acid test for image scaling software: http://i.imgur.com/X9vKa2s.png https://i.scaley.io/png-256x128/i.imgur.com/X9vKa2s.png This means that you don't use a linear color space for blending colors. Sorry about the language, the image is not made by me [1]. [1] https://web.archive.org/web/20120904060524/http://www.4p8.co... edit: I see that your backend relies on libvips to do the resizing. I have no experience with…

This image is awesome. Thank you for linking it. I'll have to keep it around to test whenever I write resizing code.

Re: Show HN: Simple image resizing/optimization service

#36

Post by hoahluke »

leni536 wrote: post #31
hoahluke wrote: post #28

Earlier quoted context omitted.

I didn't think this would come up so quickly! This can actually be fixed with an undocumented option 'gamma'[1] I didn't include it in the website, admittedly because I didn't fully understand it, and I wanted to keep the service as simple as possible. Would it make sense for this to be the default? [1] https://i.scaley.io/png-gamma-256x128/i.imgur.com/X9vKa2s.pn...

Nice! I think it should be the default. Some software might treats as a compromise between correctness and cost (doing the rescaling in linear space is usually more costly). In my view it should be correctness first. The ImageWorsener's website as an excellent reading material on image resizing and other transformations. ImageWorsener is a "correctness first" image resizing software. http://entropymine.com/imageworse…

Thanks for your detailed feedback on this, I appreciate it!

Re: Show HN: Simple image resizing/optimization service

#37

Post by throwaway2016a »

jimaek wrote: post #15

CloudFlare doesn't allow this kind of use of their service. Once you start pushing enough bandwidth they will ask you to go away. And since you offer free unlimited CDN bandwidth, when that happens and you move to a different CDN provider your bill could increase 50 times over a day.

That is really good to know about Cloudflare. CDN cost an important thing for anyone to take into consideration when they price their free/paid tiers and something that not everyone does.

I always try to price fee tiers so that one paid customer pays for about 100 or more free users and aim for at least 5% conversion of free to paid. It's not a hard-fast rule but a good starting point. If I can't hit that (even after crippling the free tier) I just drop the free tier altogether and make it a free trial instead.

Re: Show HN: Simple image resizing/optimization service

#39

Post by zzzcpan »

leni536 wrote: post #31
hoahluke wrote: post #28

Earlier quoted context omitted.

I didn't think this would come up so quickly! This can actually be fixed with an undocumented option 'gamma'[1] I didn't include it in the website, admittedly because I didn't fully understand it, and I wanted to keep the service as simple as possible. Would it make sense for this to be the default? [1] https://i.scaley.io/png-gamma-256x128/i.imgur.com/X9vKa2s.pn...

Nice! I think it should be the default. Some software might treats as a compromise between correctness and cost (doing the rescaling in linear space is usually more costly). In my view it should be correctness first. The ImageWorsener's website as an excellent reading material on image resizing and other transformations. ImageWorsener is a "correctness first" image resizing software. http://entropymine.com/imageworse…

"Correctness" is not very useful in image processing, it's all about perception and performance.

Re: Show HN: Simple image resizing/optimization service

#40

Post by jgrahamc »

jimaek wrote: post #15

CloudFlare doesn't allow this kind of use of their service. Once you start pushing enough bandwidth they will ask you to go away. And since you offer free unlimited CDN bandwidth, when that happens and you move to a different CDN provider your bill could increase 50 times over a day.

It's not bandwidth that is restricted by our terms of service it's...

SECTION 10: LIMITATION ON NON-HTML CACHING

You acknowledge that Cloudflare’s Service is offered as a platform to cache and serve web pages and websites and is not offered for other purposes, such as remote storage. Accordingly, you understand and agree to use the Service solely for the purpose of hosting and serving web pages as viewed through a web browser or other application and the Hypertext Markup Language (HTML) protocol or other equivalent technology. Cloudflare’s Service is also a shared web caching service, which means a number of customers’ websites are cached from the same server. To ensure that Cloudflare’s Service is reliable and available for the greatest number of users, a customer’s usage cannot adversely affect the performance of other customers’ sites. Additionally, the purpose of Cloudflare’s Service is to proxy web content, not store data. Using an account primarily as an online storage space, including the storage or caching of a disproportionate percentage of pictures, movies, audio files, or other non-HTML content, is prohibited. You further agree that if, at Cloudflare’s sole discretion, you are deemed to have violated this section, or if Cloudflare, in its sole discretion, deems it necessary due to excessive burden or potential adverse impact on Cloudflare’s systems, potential adverse impact on other users, server processing power, server memory, abuse controls, or other reasons, Cloudflare may suspend or terminate your account without notice to or liability to you.

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