How People Perceive Lossy Image Quality: A Study

The notion that lossy image quality is subjective is not an unreasonable hypothesis. There are many factors that play into how humans perceive quality: screen size, image scaling, and yes, even performance.

Article Continues Below

Many research projects have tackled this subject, but I’ve recently launched a survey that attempts to understand how people perceive image quality in a slightly different way: in the context of performance.

This image quality assessment serves up 25 different specimens, each of which is presented in a random lossy quality setting between 5 and 100, in both JPEG and WebP formats. As participants complete the survey, navigation, resource and paint timings are collected (when available) from the browser, as well as other client details such as a device’s resolution, pixel density, and many other pertinent details.

The real work of gathering data begins. This is where you can help out. If you have five to ten minutes to spare, please head over to and participate. When the survey is finished, I’ll post the raw data and write and article (or two) on the findings. If further experimentation is required, that will be pursued as well. I don’t know what we’ll find out, but we’ll find out together with your input. So please participate!

Thank you!

Note: If you have feedback for how to improve the survey, feel free to comment! Just be aware that your feedback can’t be implemented in this run of the survey, but it could be useful in constructing any follow-up surveys.

About the Author

A photograph of Jeremy Wagner. He is standing against a backdrop of grass and trees, with a green-to-blue swash on the left side of his hair.

Jeremy Wagner

Jeremy Wagner is more of a writer than a web developer, but he does both anyway. On top of writing Responsible JavaScript and making websites for longer than he thought probable, he has written for A List Apart, CSS-Tricks, and Smashing Magazine. Jeremy will someday relocate to the remote wilderness where sand has not yet been taught to think. Until then, he continues to reside in Minnesota’s Twin Cities with his wife and stepdaughters, bemoaning the existence of strip malls.

7 Reader Comments

  1. Interesting test. A quick note on some problems I encountered with the test: once I hit a Cloudflare error. I also found I couldn’t just click OK for images I found okay but if I moved the slider around and back to okay then I could and images with a lot of white sky were difficult to judge. And it’s easier to say if an image is awful rather than just bad than it is to say if an image is great or just good.

    If I were running the test… I might have done images next to each other for comparison. But I’m not, so… Looking forward to the results.

    Also interesting road-testing Vivaldi’s new image properties feature with some of the images.

  2. Hi Jeremy,

    Good way to see how I even perceive image quality myself.

    I feel that it had to do with the quality of the subject and to make sure that its background isn’t spilling its colours or turning into Lego bricks.

    I wonder if you might receive a lot of ‘Web Developer’ occupations from here at A List Apart?

    Must’ve gotten lots of promotion through here!

    In a front-end perspective — great website!

    Kind regards,

    Mic Sumner

  3. Image quality is increasingly important for websites and users. However, as the increase in quality means increased capacity. It is a great obstacle to the website.

  4. This is a great idea for a study – but I’m wondering, will the sample include less web-savvy folks (e.g. not ‘A List Apart’ readers)?

  5. Interesting idea. Just a detail: if my rating is exactly in the middle I still need to move the slider, otherwise it will not process my vote. I know it’s probably by design, but I did run into this 2 or 3 times 🙂

Got something to say?

We have turned off comments, but you can see what folks had to say before we did so.

More from ALA