Topic
The practice of shrinking image file size using methods like JPEG quality settings and PNG palette quantization, trading file size against visual fidelity.
PNG-8 at 124 colors encoded a red-text test poster in 48,481 bytes at an edge error of 0.13 Delta E, smaller and cleaner than every JPEG export. For flat graphics like this one, an export tool that converts everything to JPEG ships bigger files with dirtier red text.
Reality
Headless Chrome 149 wrote the same 1,345,909-byte PNG via canvas.toBlob at quality 0.1 and at 1.0, one developer's measurements show. A PNG export slider only changes the file if the tool downscales, quantises colours or switches to WebP or AVIF.
Reality
A byte-level walk of a 1.51 MB screen recording puts the untouchable palette tables at under 4 percent of the file. The 38 percent floor has to be explained by redraw rectangles that average 59 percent of the canvas.
Reality
Browsers decode eight image formats and encode three. A dev.to post documents what happens when you ask the canvas API for one of the other five: the success callback fires, and the blob it carries is a PNG.
Reality
A pipeline that turned 1074 KB into 4881 KB was not losing to the compressor. It was decoding away the interframe differencing the source already had.
Reality
A browser image tool's writeup on binary-searching JPEG quality, and on PNG, where the quality-shaped proxy it searches cannot address 155 of the 255 available palette sizes.
Reality