500px, Color Profiles, File Formats and You – 500px ISO

“Color profile support has long been a tough technical challenge — and doubly so, it would seem, in the world (wide web) of browsers. There have been several advances that have made the team at 500px re-evaluate how we handle color profiles on the site.

In the past, to be the most consistent, the most widely supported, and the most space efficient, we did two things:

1. Convert any image not using an sRGB color profile to sRGB
2. Strip the color profile from the image

Why did we do these things?

The first step is fairly obvious. Until recently, most screens were sRGB calibrated, or weren’t calibrated, but were close enough to sRGB for most purposes. This meant people with wide gamut displays wouldn’t get to see the images uploaded in wide gamut profiles (Adobe RGB, ProPhoto RGB, Display-P3, etc) in their full glory, but it also meant the most people would see something close to what the photographer intended.

The second step is a little more subtle. The default sRGB color profile is about 3KB when attached to an image (we’ve also seen non-standard profiles take 20KB). For a 5KB thumbnail, that needlessly increases the file size by more than 50%. The W3C consortium states that an image without a color profile should be assumed to be sRGB, so all should be good when an sRGB image is stripped of its profile. Stripping the color profile from the image turned out to be a pretty big deal, as it saved 25-30% in data transferred, which translated into tens of thousands of dollars in bandwidth savings per month and — most importantly — drastically sped up image downloads (especially the thumbnails). Life was good… but as we know, it’s rarely easy.”

Fascinating stuff about color profiles and how they are supported (or not) in different browsers and on different platforms. I knew this stuff was confusing, but this article does make a lot of it more understandable.

FYI, I use 500px to display my photos.

Source: 500px ISO » Beautiful Photography, Incredible Stories…500px, Color Profiles, File Formats and You – 500px ISO

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