Hacker News new | comments | show | ask | jobs | submit login

Because parsing XML can become a bottomless pit of nightmares and sorrow. Unholy floating point calculations that make Baby Jesus cry.

Meanwhile, pixel rasters are a finite array of bytes, confined to specific dimensions and resolutions. Plain old integers in 24 bit color with an 8 bit transparency channel.

And, specifically with respect to PNG, those pixel values are compressed row-by-row, using the DEFLATE algorithm.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact