UARTSIFARTSI

About UARTSIFARTSI pixel images

Every image here is a grid of black-and-white pixels of a specific width w and height h. Because there are only two colors, a w×h grid has exactly 2w·h possible pictures.

We visit them in a fixed order that everyone shares, so every image has a stable address (w, h, k) — and a shareable URL like /s/2/2/9 for the spiral order. Older /img/w/h/k links retain their original pixel order.

The order

The order starts at a single fixed origin pixel and spirals outward — and it never changes. Image 0 is the all-white 1×1 grid; image 1 makes the origin black. When every image of one size has been counted, the grid grows by exactly one row or one column, following the spiral:

1×1 → 2×1 → 2×2 → 3×2 → 3×3 → 4×3 → … → 32×32

  1. Every size is complete before the grid grows: all 2w·h pictures of a w×h grid come before any picture of the next size.
  2. Because the spiral grows one row or column at a time, the two dimensions never differ by more than one — there are no long thin strips, and the grid tends to a square.
  3. Within a size, image k is read as a binary number whose least-significant bit is the origin pixel, the next bits the pixels around it in spiral order. 0 is white, 1 is black.

Images shared before the spiral order existed keep their old addresses and look exactly as they always did — a published image URL is permanent. The current order includes only the 63 completed square and near-square sizes through 32×32, not every rectangular size.

Naming

Use email simple sign in to save settings and image names, then give any single image any name that occurs to you. Your names attach to that specific image forever. Anyone visiting that image sees every name it has ever been given — the names, not the people who submitted them. Your own history is visible only to you at /me.

Analytics

Visits are counted with Plausible, an EU-hosted service that uses no cookies and collects no personal data. The numbers are public — see the privacy policy for the link and the details.

The first few sizes

1×1   2 images        (2¹)
2×1   4 images        (2²)
2×2   16 images       (2⁴)
3×2   64 images       (2⁶)
3×3   512 images      (2⁹)
4×3   4,096 images    (2¹²)
…each size complete before the grid grows

Credits

The "chinese · common" glyphs are the 3,500 first-tier characters of the 2013 Table of General Standard Chinese Characters, and the "chinese · traditional" glyphs are the 4,808 characters of Taiwan's Chart of Standard Forms of National Characters — both drawn with Fusion Pixel Font (12px) under the SIL Open Font License.