chalkdust
Surfing on wavelets Flickr user Warm Winds Surf Shop, CC BY 2.0
Johannes Huber
H
igh-speed internet and digital storage get cheaper, but the challenge of sharing large files is one that anybody who spends their time working on computers faces. Digital images in particular can be a pain if they lead to long loading times and high server costs. If you have ever seen an image on the internet, then you have certainly encountered the JPEG format because it has been the web standard for almost 30 years. I am sure, however, that you have never heard of its potential successor, JPEG2000, even though it recently celebrated its 20th anniversary. If so, then that is unfortunate because it produces much better results than its predecessor.
Same principle but different outcome The best way to understand why different formats give very different outcomes is to look at a specific example. I have compressed a picture of myself using JPEG and JPEG2000. In both cases I sacrifice image quality in favour of space savings, which leads to errors in the resulting image. With JPEG, an image usually starts to become blurry as soon as it is compressed. Youβve probably noticed it with images on the web. Additionally, there can also be a colour loss so the image has a duller appearance overall. In my picture, the most obvious thing to suffer is that smooth colour gradients have been replaced by monochrome areas which make it appear like a picture inside a colour-by-numbers book. We can see some distinct patches of grey on the left wall for example. With JPEG2000, on the other hand, image quality usually only starts to noticeably decrease after extensive compression. As you can see, the image on the right still looks relatively unchanged. chalkdustmagazine.com
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