Jun 13, 2023 23:00:00

It is reported that the next-generation image file format 'JPEG XL' is 11% smaller in file size and 13% higher in image quality than the AVIF format

JPEG XL (JXL) is a next-generation JPEG format that uses a unique compression algorithm to compress images, illustrations, and screenshots. Such JPEG XL not only reduces the file size by about 11% compared to the ' AV1 Image File Format (AVIF)', which is a conventional image file format with a high compression rate, but also about 13% in terms of image quality compared to AVIF. reported to be excellent.

Jon Arne S.: 'So Safari will support jxl ???? .…' - Mastodon
https://mastodon.online/@jonarnes/110514451857948151

JPEG XL, which was standardized in October 2021, was developed based on Google's PIK and Cloudinary 's FUIF . The JPEG XL format is a royalty-free format that achieves a 60% improvement in compression rate compared to the JPEG format while adopting lossless compression that can restore the original data. The JPEG XL format is considered to be the next-generation JPEG format that can solve the conventional JPEG format's problem that the compression process is irreversible, noise increases, and image quality deteriorates.

On the other hand, it is reported that Google's web browser 'Chrome' is considering abolishing support for the JPEG XL format in November 2022. The reason was that it ``does not bring great advantages to existing formats,'' and that Google is promoting the WebP format as an image format for the web that conflicts with the JPEG XL format. . It was also pointed out that Google has discontinued support for the JPEG XL format and is focusing on evolving the WebP and AVIF formats for next-generation images.

Google Chrome considers abolishing support for the next-generation image standard 'JPEG XL' format, what is the reason? -GIGAZINE

However, when engineer John Arne compared the WebP format, AVIF format, and JPEG XL format using ImageEngine , in the AVIF format and JPEG XL format, the JPEG XL format has a better image quality than the AVIF format. reported to be 13% better. Also, it turned out that the file size of the JPEG XL format is compressed by about 11% more than the AVIF format.

Regarding ' SSIM ', which objectively evaluates image quality from the three elements of 'brightness', 'contrast' and 'structure', the table of the survey results by Mr. Arne using the calculation tool ' DSSIM ' is below. According to Arne, this graph shows the 'visual similarity' between the original image and the image optimized for each file format. 'Visual similarity' is said to be better the closer it is to 0, and in the WebP format and AVIF format, the 'average' and 'median' shown in blue were around 0.0025 In contrast, the JPEG XL format improves the median to about 0.002. You can also confirm that the JPEG XL format outperforms the other two formats even at the 90th percentile shown in gray.

Below is a table comparing file sizes. For the original image in JPEG format, AVIF, WebP, and JPEG XL formats all compress and reduce the file size compared to the original file, but you can see that the compression rate of JPEG XL format is particularly high. .

Regarding the fact that the JPEG XL format exceeds the performance of the conventional AVIF format, Mr. Arne said, ``Let more developers know the performance of the JPEG XL format and test whether it meets their development needs. JPEG XL has the potential to replace existing JPEG, GIF, PNG and WebP formats with equivalent or better quality and smaller file sizes.'

On the other hand, Hacker News says, ``When comparing file formats, it is possible to compare image quality, file size, compression time, decompression time, etc., but rather than comparing them individually, consider various factors and combine them. should be evaluated,” he said .