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Card 225 of 9982026-09-08 issue

Observed arrival · 2026-09-08

Duotone.dev, where luminance gets remapped

duotone.dev Observed source
Editorial interest 84/100 Selection signal · not a rating of the site

A browser-based image tool that maps photograph luminance between two colours and exports the result as SVG, Canvas, CSS, or hex stops.

Landing page captured for the 2026-09-08 issue.

Field notes

The tool maps each image pixel through a 256-stop colour ramp, with midpoint and contrast controls determining how source tones are placed. Its stated luminance method is the WCAG relative-luminance formula in linear light, avoiding the channel-averaging shortcut the guide says can distort greens and blues. Outputs include an SVG filter, Canvas code, and plain hex stops, while six named presets provide starting configurations for subjects such as cyanotype, newsprint, and fuchsia.

Observed signals

Read the marks

Editorial observations of this landing page, not a rating.

OpenPublic substance visible
PrettyNotable craft visible
ProPolished or operationally mature
NicheUnusually specific use

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duotone.dev

Landing page observed 2026-09-08. The live site may have changed.