sampling
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Fundamentals Sampling: What One Pixel Covers, and What Falls Between
Lesson 2 of The Image as Data. One photosite on this camera is 5.527 µm and covers 1.056 arcminutes of the room. The table in the frame is ribbed at 7.4 pixels per cycle; keep every 8th pixel and it comes back at 96 pixels per cycle — thirteen times too coarse, and predicted exactly by folding the frequency.
Fundamentals The Image as Data: The Grid, the Integers, the Axes, and the File
The unit overview: what an array actually holds, where its samples sit, how finely each one is written down, what its three numbers mean, and what the encoder did before you read any of it. Measured on one photograph: two thirds of a colour image is interpolated, a 7.4-pixel ribbing returns as 96-pixel banding when you decimate by eight, bit depth stops buying anything at 9.4 bits, and the naive route from file to colour lands 9.54 ΔE from the light in the room.