LED PWM Duty Cycle Gamma 2.2 Brightness

Map caller target perceptual-brightness fractions through explicit gamma-2.2 power heuristic to duty and bounded PWM codes; uncalibrated, no LED electrical current, thermal safety or exact visual response guarantee.

Description

A gamma 2.2 power heuristic maps target brightness to PWM duty.

A gamma 2.2 power heuristic maps target brightness to PWM duty. A device’s actual response requires calibration.^[1]

Enter brightness fractions 0–1 and integer resolution 1–16 bits. Return duty fractions and half-up rounded codes; empty brightness lists are allowed.

When to use LED PWM Duty Cycle Gamma 2.2 Brightness

Use LED PWM Duty Cycle Gamma 2.2 Brightness when you need to evaluate the supplied records under the calculation and evidence rules below. No LED current, thermal safety or exact visual response is established.

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 LED PWM Duty Cycle Gamma 2.2 Brightness 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 perceivedBrightnessFractions, pwmResolutionBits using the field table and calculation rules, then run the tool.
Read gamma22DutyFractions, roundedPwmCodes. 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
perceivedBrightnessFractions	Perceived brightness fractions	list of number	Required
pwmResolutionBits	Pwm resolution bits	number	Required

Enter brightness fractions 0–1 and integer resolution 1–16 bits. Return duty fractions and half-up rounded codes; empty brightness lists are allowed.

duty=brightness^2.2; code=round(duty×(2^bits−1))

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

Output field	Meaning	Value type
gamma22DutyFractions	Gamma22 duty fractions	list of number
roundedPwmCodes	Rounded pwm codes	list of number

json

{
  "input": {
    "perceivedBrightnessFractions": [
      0,
      0.5,
      1
    ],
    "pwmResolutionBits": 8
  },
  "output": {
    "gamma22DutyFractions": [
      0,
      0.217637640824031,
      1
    ],
    "roundedPwmCodes": [
      0,
      55,
      255
    ]
  }
}

Limitations and assumptions

No LED current, thermal safety or exact visual response is established.

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 WS2812 GRB Byte Order Check: WS2812 GRB serialization sends green before red and blue. An observed stream can have wrong values or wrong length. For a complementary task, use Perceived Brightness HSP Calculator: HSP brightness is a weighted root of squared encoded channels. It is a perception heuristic distinct from relative luminance.

References

LED PWM Duty Cycle Gamma 2.2 Brightness — tool.io

Similar or alternative tools

WS2812 GRB Byte Order Check
WS2812 GRB serialization sends green before red and blue. An observed stream can have wrong values or wrong length.
Perceived Brightness HSP Calculator
HSP brightness is a weighted root of squared encoded channels. It is a perception heuristic distinct from relative luminance.