Protanomaly Severity Interpolation

Interpolate adjacent published Machado protanomaly matrices at 0.1 severity steps in linear RGB, then encode/clamp and report excursions; a model visualization, not an exact individual view, clinical severity scale or accessibility certification.

Description

Protanomaly simulation uses severity-dependent matrices.

Protanomaly simulation uses severity-dependent matrices. Interpolating neighboring published matrices differs from blending only the two endpoints.^{[1, 2]}

Enter normalized RGB and severity 0–1. Decode to linear sRGB, locate neighboring 0.1-spaced Machado matrices, interpolate their outputs, clamp and encode. Return RGB and strict linear-excursion indexes; severity 0 uses identity.

When to use Protanomaly Severity Interpolation

Use Protanomaly Severity Interpolation when you need to evaluate the supplied records under the calculation and evidence rules below. Severity is a model parameter rather than a clinical scale; no exact individual view or accessibility certification is supplied.

Prepare colors in the stated color space and scale. Use encoded RGB fractions, linear RGB, Lab, xy, byte values or ink percentages exactly as requested; supply caller tolerances and reference conditions.

How to use Protanomaly Severity Interpolation and understand its results

Prepare colors in the stated color space and scale. Use encoded RGB fractions, linear RGB, Lab, xy, byte values or ink percentages exactly as requested; supply caller tolerances and reference conditions.
Enter baseRgb, severityFraction using the field table and calculation rules, then run the tool.
Read simulatedRgb, clippedLinearChannelIndices. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
baseRgb	Base rgb	list of number	Required
severityFraction	Severity fraction	number	Required

matrixOutput=(1−weight)×lowerMatrixOutput+weight×upperMatrixOutput

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
simulatedRgb	Simulated rgb	list of number
clippedLinearChannelIndices	Clipped linear channel indices	list of number

json

{
  "input": {
    "baseRgb": [
      1,
      0,
      0
    ],
    "severityFraction": 0
  },
  "output": {
    "simulatedRgb": [
      0.9999999999999999,
      0,
      0
    ],
    "clippedLinearChannelIndices": []
  }
}

Limitations and assumptions

Severity is a model parameter rather than a clinical scale; no exact individual view or accessibility certification is supplied.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Protanopia Simulation Matrix: A protanopia visualization applies a published full-severity model in linear sRGB. Clipping remains visible in the returned evidence. For a complementary task, use Color-Blind Safe Palette Band Check: Palette distance under three dichromacy simulations provides a model-based separation screen. It cannot guarantee accessibility for every viewer.

Further background: A physiologically-based model for simulation of color vision deficiency (2009).

References

Protanomaly Severity Interpolation — tool.io
A physiologically-based model for simulation of color vision deficiency (2009) — Machado, Oliveira and Fernandes

Similar or alternative tools

Protanopia Simulation Matrix
A protanopia visualization applies a published full-severity model in linear sRGB. Clipping remains visible in the returned evidence.
Color-Blind Safe Palette Band Check
Palette distance under three dichromacy simulations provides a model-based separation screen. It cannot guarantee accessibility for every viewer.