Crate linear_srgb 

Fast linear↔sRGB color space conversion.

This crate provides efficient conversion between linear light values and sRGB gamma-encoded values following the IEC 61966-2-1:1999 standard.

Module Organization

• default - Recommended API with optimal implementations for each use case
• simd - SIMD-accelerated functions with full control over dispatch
• scalar - Single-value conversion functions (f32/f64)
• lut - Lookup table types for custom bit depths

Quick Start

use linear_srgb::default::{srgb_to_linear, linear_to_srgb};

// Convert sRGB 0.5 to linear
let linear = srgb_to_linear(0.5);
assert!((linear - 0.214).abs() < 0.001);

// Convert back to sRGB
let srgb = linear_to_srgb(linear);
assert!((srgb - 0.5).abs() < 0.001);

Batch Processing (SIMD)

For maximum throughput on slices:

use linear_srgb::default::{srgb_to_linear_slice, linear_to_srgb_slice};

let mut values = vec![0.5f32; 10000];
srgb_to_linear_slice(&mut values);  // SIMD-accelerated
linear_to_srgb_slice(&mut values);

Custom Gamma

For non-sRGB gamma (pure power function without linear segment):

use linear_srgb::default::{gamma_to_linear, linear_to_gamma};

let linear = gamma_to_linear(0.5, 2.2);  // gamma 2.2
let encoded = linear_to_gamma(linear, 2.2);

LUT-based Conversion

For batch processing with pre-computed lookup tables:

use linear_srgb::default::SrgbConverter;

let conv = SrgbConverter::new();  // Zero-cost, const tables

// Fast 8-bit conversions
let linear = conv.srgb_u8_to_linear(128);
let srgb = conv.linear_to_srgb_u8(linear);

Choosing the Right API

Use Case	Recommended Function
Single f32 value	default::srgb_to_linear
Single u8 value	default::srgb_u8_to_linear
f32 slice (in-place)	default::srgb_to_linear_slice
u8 slice → f32 slice	default::srgb_u8_to_linear_slice
Manual SIMD (8 values)	default::srgb_to_linear_x8
Inside #[multiversed]	default::inline::srgb_to_linear_x8
Custom bit depth LUT	lut::LinearTable16

Feature Flags

• std (default): Enable std library support
• unsafe_simd: Enable unsafe optimizations for maximum performance

no_std Support

This crate is no_std compatible. Disable the std feature:

linear-srgb = { version = "0.2", default-features = false }

Modules

default

Recommended API with optimal implementations for each use case.

lut

Lookup table types for sRGB conversion.

scalar

Scalar (single-value) conversion functions.

simd

SIMD-accelerated conversion functions.

Macros

simd_multiversion

Primary SIMD targets for most functions (x86_64 version).

simd_multiversion_extended

Extended SIMD targets (x86_64 version).

simd_multiversion_full

Full SIMD targets (x86_64 version).