Two quick quality-of-life options for logo and background-heavy imports:
- Skip-white: near-white pixels (r,g,b >= threshold, default 230) are
marked transparent in the output so they don't consume credits. Useful
when the source has a white background you don't want to paint.
- Paint-transparent: fully-transparent source pixels are treated as opaque
white before quantization. Useful if the canvas background is white and
you want empty regions of a logo to blend in.
Both toggles compose with every existing dither method; paint-transparent
runs first, so combining the two leaves originally-transparent pixels as
skip (since they're synthesized white, then the skip-white pass drops
them).
UI adds the two checkboxes and a threshold slider shown only when
skip-white is on. CLI gains --skip-white, --white-threshold,
--paint-transparent. 4 new unit tests pin the behavior including the
paint+skip interaction.
Brightness, contrast, saturation, and gamma adjustments before palette
quantization. Pure-function applyColorCorrection in src/lib keeps the CLI
and browser importer in sync. Inserted post-resize so slider moves stay
responsive on large sources; precision loss is negligible through a
32-color palette.
UI is a collapsible "Color correction" section with four sliders, live
values, a "Reset" button, and an "on" badge when any value differs from
default. CLI gains --brightness, --contrast, --saturation, --gamma
(all -100..+100 except gamma which is 0.1..3.0).
9 unit tests pin down identity, saturate-to-0-or-255 clamping, greyscale
at saturation=-100, gamma midtone direction, and alpha preservation.
Replace the single Floyd-Steinberg toggle with a method dropdown offering
none, floyd, atkinson, jarvis, burkes, sierra, sierra-lite (error diffusion)
and bayer-2 / bayer-4 / bayer-8 (ordered). Kernels live in
src/lib/dither-kernels.js as plain data; rgbaToPalette dispatches via a
shared runErrorDiffusion runner and a runOrderedDither for Bayer.
The legacy `dither: true` option keeps working (maps to `method: 'floyd'`),
so existing CLI invocations and tests stay green. CLI gains
`--dither-method <name>` which takes precedence over `--dither`.
13 unit tests cover exact-palette hits, transparent pixels, all-method
smoke, kernel weight sums (Atkinson=0.75, others=1.0), and verify Bayer
actually scatters on mid-grey where plain nearest would produce one color.
Pure-function transformRgba in src/lib/image-transform.js supports flip H,
flip V, and rotation in 90° steps (fixed application order: rotate → flipH
→ flipV). Wired into the importer pipeline before resize with buttons for
each op; ±90° rotations auto-swap the resize dims so output aspect tracks
the rotation. CLI gains --flip-h, --flip-v, --rotate flags using the same
shared module.
8 new unit tests cover identity, each flip, 90/180/270 rotation, the
flipH+flipV ≡ 180° identity, and invalid rotation rejection.
Add W/H inputs, aspect-ratio lock, resampling method dropdown (nearest /
bilinear / box), "Fit to canvas" (respects current origin) and "1:1" reset
buttons to the import panel. Pipeline now runs resize before palette
quantization so dither/skip-matching operate on the final dimensions.
Shared src/lib/image-resize.js is reused by scripts/image-to-colors.js,
which gains --width, --height, --method flags with aspect-preserve when
only one dimension is provided.
Convert PNG/JPG/WebP to rplace palette JSON (nearest-color or Floyd-Steinberg
dither) and upload at a target (x, y) with client-side credit throttling and
429 backoff. Shared palette conversion lives in src/lib/image-to-palette.js so
the browser importer can reuse it.
tiennm99