eink_dither 2.2.0

Apply dithering algorithms to quantize full-color images for limited-color displays like E-Ink, Thermal Printers, and Dot-Matrix Screens.

2.2.0

• ✨ New feature: added the Sierra family of error-diffusion kernels (Frankie Sierra):
  • DitherKernel.sierra3 — Sierra / Sierra-3, 10 neighbours, divisor 32.
  • DitherKernel.sierra2 — Two-Row Sierra / Sierra-2, 7 neighbours, divisor 16.
  • DitherKernel.sierraLite — Sierra Lite / Sierra-2-4-A, 3 neighbours, divisor 4.

2.1.0

• 💥 Breaking change: renamed the ordered-dither strength parameter back to intensity for a more fitting, consistent name across the dithering API:
  • EInkImageProcessor.strength → intensity
  • ditherImage, ditherImageOrdered, ditherImageBayer, ditherImageBlueNoise parameter strength → intensity
  • Update call sites, e.g. EInkImageProcessor(intensity: 1.0) and ditherImage(image, intensity: 1.0).
• ✨ New feature: added a patternSize parameter ("Pattern Size") to control the scale of the dither pattern, similar to the control in many halftone editors:
  • EInkImageProcessor.patternSize
  • ditherImage, ditherImageOrdered, ditherImageBayer, ditherImageBlueNoise parameter patternSize (default 1)
  • For ordered kernels (Bayer / blue noise) each threshold-matrix cell now covers patternSize×patternSize pixels instead of 1×1, stretching the pattern to be coarser / larger.
  • For error-diffusion kernels (Floyd–Steinberg, Stucki, etc.) the diffusion now runs on a patternSize×patternSize-block downsampled grid and each block is expanded back, so the dither "dots" grow with patternSize.

2.0.0

• 💥 Breaking change: renamed the ordered-dither strength parameter for a consistent naming convention across the dithering API:
  • EInkImageProcessor.intensity → strength
  • ditherImage parameter bayerStrength → strength
  • Update call sites, e.g. EInkImageProcessor(strength: 1.0) and ditherImage(image, strength: 1.0).
• 💥 Breaking change: ditherImageOrdered now takes a DitherKernel kernel instead of a raw List<List<double>> matrix. The threshold matrix is resolved internally via _orderedDitherMatrix, so callers pass the kernel (e.g. ditherImageOrdered(image, quantizer, DitherKernel.bayer4x4, strength)) rather than the matrix itself. ditherImageBayer and ditherImageBlueNoise continue to work unchanged.
• ♻️ Refactored the ordered-dither branch detection in ditherImage: added a lightweight _isOrderedDither helper so the branch test no longer fetches the threshold matrix; the matrix is looked up only once, inside ditherImageOrdered.

1.0.1

• 🔗 Adjusted the image / badge links in the documentation.

1.0.0

• 🎛️ 8 dithering kernels — error-diffusion (Floyd–Steinberg, Stucki, Atkinson, Jarvis–Judice–Ninke, Burkes, False Floyd–Steinberg (Heckbert)), ordered (Bayer 2×2/4×4/8×8, Blue Noise), and none (no dithering).
• 🔀 4 scan orders for error-diffusion kernels (raster, serpentine, zigzag, Hilbert space-filling curve).
• 🎨 8 E-Ink palettes — from pure black/white up to 7-color (Gallery 7) and 16-level grayscale (Carta 16).
• 🧮 Universal quantizer EInkPaletteQuantizer that maps any color to the nearest E-Ink color in a palette using Euclidean RGB distance.
• ⚙️ A configurable EInkImageProcessor with both synchronous (process) and isolate-based asynchronous (processIsolated) processing.