GitHub link.

Controls

Key	What it does
Alt+H	Show or hide the info overlay. Remembered per site
Alt+M	Size: fit the window width → biggest whole-number zoom → one image pixel per screen pixel
Alt+Q	Filter: Lanczos3 → nearest → browser. Same size each time, so you can compare
Alt+P	Turn on or off for the site you're on. Remembered per site
Alt + left clickon an image	Show that one image at one image pixel per screen pixel
Alt + right clickon an image	Show that one image at twice its own resolution
Alt+G	Show or hide the overlay's diagnostic rows (size, factor, status, memory)

I'd attach images, but I'm pretty sure reddit will compress them, so go check them out here.

I hope reddit doesn't butcher the quality too bad. I want everyone to be counting cats, not pixels.
Higher quality on imgur.

​

Hint 1: The number of cats is >!-7-!<, unless you can find more.

Hint 2: Not counting the obvious, one is >!pretending to be part of the kerb!<.

Hint 3: Another is a bit >!pixelated!<, but can be found >!blending in with a foreground tree!<.

Hint 4: The sneakiest of them all is an even >!greater kerb-blender!<.