sensus

Sensory perception simulation for images — apply color blindness, low vision, visual field defects, and (soon) hearing loss filters to ordinary photos. Built as a Rust crate so it can power accessibility demos, educational tools, and apps like universal-experience.

sensus (Latin) — "sense, perception, feeling".

Status

v0.1.0 — stable release on crates.io. All Phase 1–3 vision filters are implemented. See docs/roadmap.md for the full phase tracker.

Filters

Vision

Hearing (Phase 4)

• Hearing loss curves, pitch shift, balance / vertigo simulation applied to audio buffers (#7, #8, #9).

Each filter ships with a short note on when to see a doctor — sensus is designed both as an empathy / education tool and as an early-warning primer for symptoms worth taking seriously.

Install

cargo install sensus

This installs the sensus CLI binary. Pre-built binaries for Linux, macOS (Intel & Apple Silicon), and Windows are also attached to each GitHub Release.

CLI usage

# Phase 1: color vision deficiency simulation
sensus -i photo.png -o photo-deuteranopia.png --filter deuteranopia --strength 1.0
sensus -i photo.png -o photo-grayscale.png    --filter achromatopsia --strength 1.0
sensus -i photo.png -o photo-mild-protan.png  --filter protanopia    --strength 0.5

# Phase 2: focus / refraction (disk blur in linear sRGB)
sensus -i photo.png -o photo-myopia.png       --filter myopia        --strength 1.0
sensus -i photo.png -o photo-presbyopia.png   --filter presbyopia    --strength 0.7
# astigmatism with explicit cylinder axis (degrees, 0..=180; default 90)
sensus -i photo.png -o photo-astig.png        --filter astigmatism   --strength 1.0 --axis 90

# Phase 3: visual field defects and light conditions
sensus -i photo.png -o photo-glaucoma.png     --filter glaucoma      --strength 1.0
sensus -i photo.png -o photo-cataract.png     --filter cataract      --strength 0.8

# Pipeline: chain multiple filters in one pass
sensus -i photo.png -o out.png --filter deuteranopia --filter myopia --strength 1.0
sensus -i photo.png -o out.png --filter glaucoma --filter cataract --strength 0.7

Flags:

Run sensus --help for the full list of filter names.

Library usage

sensus-core is the pure-logic crate (no I/O). Take a DynamicImage in, get a DynamicImage out.

# Cargo.toml
[dependencies]
sensus-core = "0.1"

use image::DynamicImage;
use sensus_core::{apply, vision, Filter};

fn examples(img: DynamicImage) -> sensus_core::Result<()> {
    // Direct call (most ergonomic for a known filter):
    let _full   = vision::deuteranopia(img.clone(), 1.0)?;
    let _mild   = vision::deuteranopia(img.clone(), 0.5)?;
    let _gray   = vision::achromatopsia(img.clone(), 1.0)?;
    let _near   = vision::myopia(img.clone(), 1.0)?;
    let _astig  = vision::astigmatism(img.clone(), 0.5, 45.0)?; // axis in degrees

    // Or via the dispatching facade (handy when the filter is dynamic).
    // `apply()` always uses the default 90° axis for astigmatism — call
    // `vision::astigmatism()` directly if you need a custom axis.
    let _shifted = apply(Filter::Protanopia, img, 1.0)?;
    Ok(())
}

strength is clamped to [0.0, 1.0]. Filters in Phase 1 simulate color vision deficiency in linear sRGB space using the Machado 2009 model; achromatopsia uses the BT.709 photopic luminance. (BT.601 luma coefficients are designed for NTSC CRTs and are colorimetrically wrong for sRGB images.) Phase 2 (refraction) applies an optically correct disk blur in linear sRGB — radius derived from 0.5 × pupil_diameter × |D| (Smith–Helmholtz gives angular diameter, so the radius is half), min(W, H)-relative, edge-replicated borders. astigmatism is 1D directional blur (pure cylindrical lens / line spread function), not an elliptical disk — see docs/overview.md for the full derivation.

The same function signatures can be applied frame-by-frame for video, or chained together via sensus_core::pipeline (Phase 4).

Crates

License

MIT (c) 2026 kako-jun. See LICENSE.