from Hacker News

The New Test Images – Image Compression Benchmark

by Zababa on 9/2/24, 2:19 PM with 15 comments

  • by andrewla on 9/5/24, 7:35 PM

    I understand why it can be problematic to use humans in test images, but this is in conflict with the purpose of test images. The purpose, briefly, is to allow human eyes to easily spot defects in image processing. While we can use automated methods as well especially for formal analysis of fidelity, in the end the reason why we are displaying images is for human consumption.

    We don't need to to Lena or the other traditional images, but it should be possible to find a usable example -- even if it's just the grimacing guy from the meme or something.

  • by hoten on 9/5/24, 7:44 PM

    More context, here is what the old "Lena" test image is all about: https://womenlovetech.com/losing-lena-why-we-need-to-remove-... (nsfw, it's a Playboy pic)

  • by Zababa on 9/2/24, 2:22 PM

    A bit more context from the page:

    > The images historically used for compression research (lena, barbra, pepper etc...) have outlived their useful life and its about time they become a part of history only. They are too small, come from data sources too old and are available in only 8-bit precision.

    > These high-resolution high-precision images have been carefully selected to aid in image compression research and algorithm evaluation. These are photographic images chosen to come from a wide variety of sources and each one picked to stress different aspects of algorithms. Images are available in 8-bit, 16-bit and 16-bit linear variations, RGB and gray.

    > You are encouraged to use these images for image compression research and algorithm evaluation. Suggestions for further improvements are always welcome.

    I am currently looking at different image formats/png optimizers and trying to compare them, so having a set of images to compare is nice.

    I do feel like they're not exactly representative of what an image can be on the web or on my computer. I was thinking of adding a few things for my own use: a screenshot, an image macro, a page of manga.

  • by sliq on 9/5/24, 10:09 PM

    This page was last updated in 2015, 9 years ago, and ALOT has happened in image compression and on the web in these 9 years. And the samples are just so totally weird, they are not representative for anything.

  • by munchler on 9/5/24, 8:03 PM

    > each one picked to stress different aspects of algorithms

    Really? Photographically, these images are kinda crappy - the kind of casual snapshot one might take and then delete. The cathedral image, for example, is both underexposed and overexposed. I guess this isn't too surprising, since it was taken on a Nikon D70 from 2004, which had pretty limited dynamic range. This hardly seems like a good example to choose for testing image compression, since it lacks a lot of useful detail. Or maybe this was a deliberate choice? What were the actual criteria used to choose these images?

  • by entropie on 9/5/24, 8:47 PM

    is nightshot_iso_1600 and nightshot_iso_100 interchanged? that looks not right to me. Iso 100 looks way brighter.

  • by throwaway7679 on 9/5/24, 9:31 PM

    (2008)