Green Sprite
The classic green-screen remover. Global key over green dominance, optional edge cleanup + green repair for contaminated outlines.
--profile green · reference →
MutaSprite · v0.15.3 · Windows 10 / 11
Every function. One page. No fluff.
What each operation does, its exact options, and its CLI call — straight from the reference. One shot per function. Full detail lives in the handbook.
MutaSprite is a free, 100%-local Windows toolbox that turns green-screen sprites into clean transparent PNGs with pixel-perfect chroma keying (free forever, no account, no cloud). Optional one-time modules add AI-art-to-pixel-art conversion (Pixelize), 9-slice + SliceX cutting, folder Batch automation and Undetail — €3–€12 each, or the Studio-Kit for €19. Sold via Gumroad and itch.io.
Runs 100% locally — no cloud, no GPU
PNG in, PNG out — never resampled unless you ask
Deterministic — same input, same output
01
ChromaKey · operation chromakey
Free forever
Green-screen sprite in. Clean PNG out. Free forever.
All nine keying profiles — full quality, hard pixel edges (alpha 0/255, no resampling). No watermark, no trial, no account. Pick a profile per job:
Green Sprite (hard, content-safe)
Removes only edge-connected background green — green that's part of your sprite stays untouched.
--profile green_hard
Residue Repair
No keying — cleans green residue and rim glow off already transparent assets without touching content.
--profile residue
Auto
Measures the key per image, applies a soft matte — and passes through untouched when there's no key to find.
--profile auto (default)
Custom Color
Key any background color — pick it with the pipette or pass #RRGGBB, with tolerance 0–160.
Magenta Sprite / Outline
Magenta key tuned for sprites and outline art — when green would collide with your palette.
--profile magenta_sprite
Magenta FX / Water
Magenta key for translucent FX and water sprites — keeps the soft interior, kills the key.
--profile magenta_fx
Magenta FX / Water Plus
The stronger FX variant for stubborn magenta edges and heavy spill.
--profile magenta_fx_plus
FX / Glow (Soft-Matte)
Soft-matte profile for glow, smoke and sparkles — translucent alpha instead of a hard cut.
--profile fx_glow
Shared options:
--key-color #RRGGBB
--key-tolerance 0–160
--edge-cleanup on|off
--spill-radius 1–4
--spill-strength conservative…maximum
--green-repair off…strong
02
Pixelize · the flagship module · --operation pixelize
€12 once
Your art in. Real pixel art out.
Pixelize turns painterly, rendered or AI-generated images into intentional classic pixel art: a true low-res grid, a curated palette, clean flat areas. Offline, deterministic, no GPU.
More palettes — same art, by name
- Pipeline
- Deterministic, 5 steps: area downscale → palette → per-pixel mapping (optional dither) → alpha → output. Same settings, byte-identical result (on the same app version).
- Presets
- Clean Flat (default) · Retro (DB16) · Painterly→Pixel · Mega Drive · SNES · Custom
- Resolution
- Target px 48 / 64 / 96 / 128 / 256 (default 128, up to 512 opt-in, manual 8–1024) — or factor 2/3/4/6/8
- Palettes
- Auto (median-cut in perceptual Oklab, K colors) · DawnBringer 16 · PICO-8 · Game Boy DMG · Mega Drive (3-bit) · SNES (5-bit)
- Colors K
- 8 / 16 / 24 / 32 / 48 / 64 (default 24; up to 512 opt-in)
- Dithering
- Off (default) · Bayer 2×2 · Bayer 4×4 · Floyd–Steinberg
- Alpha & crop
- Hard (threshold 128) or preserved alpha · auto-crop to alpha content before downscale (default on)
- Output
- Small / upscaled / both — integer upscale ×1/2/4/8, nearest-neighbor
Generated a concept you love? Painted something at the wrong resolution? Pixelize makes it shippable. It doesn't generate anything — it transforms your image, deterministically, on your machine.
Is this an AI tool?No — it's a deterministic converter, not a generator. Bring your AI art; Pixelize turns it into an authored, ownable pixel-art asset. No prompts, no variation, no credits.
Pixelize or Undetail?Undetail coarsens (block mosaic, no palette). Pixelize converts — real low-res grid plus a curated palette.
Which resolution for characters?128 px is the robust default — 64 px is often too coarse for faces.
In development: selective outline (v1.1) and custom palette import (.hex/.pal — bring any Lospec palette).
--pixelize-palette auto|db16|pico8|gameboy|md|snes
--pixelize-target-px 128
--pixelize-colors 24
--pixelize-dither off|bayer2|bayer4|floyd
CLI requires Batch & Automation / Studio-Kit
Full reference →
03
Slice + SliceX · --operation slice / slice-grid
€9 once · one SKU
Two cutters, one module.
Standalone and engine-agnostic — process your assets before the import step, no Unity or Godot required.
- Slice
- 4 edge insets → up to 9 regions (
tl…br). Corners stay pixel-fixed; edges tile pixel-perfect (default) or stretch nearest-neighbor. 3-slice = one inset pair at 0. - Target
- Pixel size (W × H) or factor · output: scaled PNG, regions cut separately, or both
- SliceX
- Free horizontal/vertical grid lines, dragged from the rulers — up to 25 cells, each exported as its own PNG (
name_r0c0.png). Pure cropping, never resampled. - Labels
- Live segment-size labels on every line (e.g.
76px), optional absolute positions
--slice-left/right/top/bottom px
--slice-fill tile|stretch
--slice-grid-xs "70,140,210"
--slice-grid-ys "65,130"
Full reference →
04
Batch & Automation · global unlock
€9 once
Point it at a folder.
Every operation you own — the free ChromaKey included — runs across a whole folder. Modules are what you can do. Batch & Automation is how fast.
- Scope
- Global: batches any owned operation — ChromaKey (free), Pixelize, UnDetail, Slice — with the current tab settings
- Preview
- File-list preview before the run; result tally processed / skipped / failed after
- Overwrite
- Overwrite (default) · skip · number — per-run strategy for existing files
- Report
- Off · TXT · CSV run log; optionally open the output folder when done
- Control
- Runs in a worker thread — UI stays responsive, cancel anytime; presets for recurring jobs; subfolders optional
- CLI
- Unlocks headless execution of every operation for scripts and pipelines. Docs are public;
--check-updatestays free. Paid operations also need their own module.
clean_sprite_chromakey.exe in.png out.png --profile green
CLI requires Batch & Automation / Studio-Kit
CLI overview →
05
UnDetail · --operation undetail
€3 once
Start here
The €3 fixer.
Too-fine art becomes a coarser, intentional pixel structure — block by block, with no gray fringes and no half-transparent mush. Coarsen with UnDetail; convert with Pixelize.
- Blocks
- Block size 2 / 3 / 4 / 6 / 8 (default 4) · sampling per block: dominant (default), median, average
- Clean edges
- RGB sampled only from opaque pixels; edge-RGB bleed under transparent rims — no gray fringes, no pseudo-alpha
- Smoothing
- Smooth-area snap (threshold 0–32) unifies flat areas; island cleanup absorbs tiny color outliers; single-color blocks keep their exact color
- Quantize
- Off · light (16 steps, default) · strong (32 steps) — per-channel posterize, no curated palette (that's Pixelize)
- Output
- Original size (default) · small (32–256 px or manual) · both · alpha hard / coverage / preserve
Own it once
Free forever to start. €19 for everything.
Try the free half first.
All nine keying profiles, full quality, free forever. Buy a module the day you hit its wall.
v0.15.3 · 31 MB · Windows 10 / 11