Screenshot and recording

This sensor captures what the interface looks like, as an image or a video, to compare with an approved image or to hand to a model or a person as evidence. Loops read it because a broken layout is plain in a picture and hard to see anywhere else.

What it sees

What the screen showed at the moment of capture, in pixels. The capture is deterministic; the judgement is separate, and can be a pixel diff, a model or a person. A diff sees that something changed, not whether the change is wrong, and a picture shows nothing of the states it was not taken in.

Reading the signal

• Within tolerance: the capture matches the approved image closely enough.
• Pixel difference over the tolerance: the screen changed. It is a regression, or an intended change whose approved image must be updated on purpose.
• A frame to judge: no comparison; a model or a person judges the capture, and their verdict is the signal.

Many differences come from the capture, not the work: a screen caught before it settled, a clock, an animation, a font that renders differently on another machine. Let the screen settle before capturing, and mask the regions that change on their own.