April 17, 2026

Taste the rainbow, bicker about bins

Generating a color spectrum for an image

From fruit pic to rainbow map — fans cheer, devs want code, one wants it round

TLDR: A creator built Spectrimage to show every color in a photo as a frequency-based rainbow. Commenters loved the look, pushed for a circular “vectorscope” version, asked for the source code, and argued for a minimum height so the rainbow stays readable and doesn’t devolve into random blobs.

A simple fruit photo just sparked a color riot. The creator’s Spectrimage tool turns any picture into a smooth rainbow strip showing how much orange, purple, and green is really there. After early tries that either squashed nuance or jumbled order, the latest approach sorts pixels by color and brightness to avoid that weird barcode look. Translation: less math lecture, more “wow, that’s the vibe” — and the crowd noticed.

The top comment came in hot with pure approval: “Visually the results are very compelling!” Meanwhile, the tinkerers arrived with requests. One wag begged, “make it polar and you almost have a vectorscope” — basically a retro TV color radar; imagine the rainbow going circular and you’ve got the picture. Another voice of the open-source chorus asked for the code like it’s a constitutional right. And then the design debate kicked off: a sharp-eyed commenter focused on a later iteration and warned that letting the bars shrink to nothing makes the whole thing lose its “spectrum-ness.” Their fix? Keep a minimum height and use saturation to show when a color’s barely there.

So we’ve got three camps: the thrilled fans, the build-it-round nerds (paging the vectorscope crowd), and the UX nitpickers defending the rainbow’s dignity. The takeaway: this isn’t just a color strip — it’s a feelings meter for photos, and the community wants it gorgeous, open, and maybe even circular.

Key Points

  • The project builds Spectrimage for Chromaculture to visualize the full color composition of images.
  • Median cut quantization (32 swatches) fails for visualization because it equalizes bucket sizes and limits nuance.
  • A hue-based histogram in HSL (72 five-degree bins) restores ROYGBIV order and reflects frequency but merges different lightness values.
  • Pixel-level hue sorting with many segments reveals dark–light striping due to mixing pixels of different lightness at the same hue.
  • Iteration 4 introduces band sorting with lightness to mitigate striping, though detailed explanation is truncated.

Hottest takes

Visually the results are very compelling! — MontagFTB
Now make it polar and you almost have a vectorscope... — orbital-decay
loses the "spectrum-ness" — loneboat
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