Image Threshold Black and White
Convert image luminance into two colors with a manual or automatic Otsu threshold, optionally inverted.
A QUICK WALKTHROUGH
How to use this tool
- Choose image
- Convert image luminance into two colors with a manual or automatic Otsu threshold, optionally inverted.
- Preview and prepare PNG; Download PNG
Image Threshold Black and White
Transparency is flattened on white before computing rounded luminance: 0.2126 R + 0.7152 G + 0.0722 B. Values above the threshold become white, the others black. Otsu maximizes between-class variance over a 256-bin histogram; ties choose the lowest threshold. Uniform images use their sole luminance as the threshold.
Choose image
Choose a valid PNG, JPEG or WebP up to 10 MB. Input and output: at most 8192 px per side and 12 megapixels. Working pixel buffers are bounded to 144 MB; browser decoding and encoding may need additional memory.
PNG
Files stay in your browser. PNG export discards source metadata, color profiles and animation; only the first frame is used.
GOOD TO KNOW
Common questions
Choose image?
Choose a valid PNG, JPEG or WebP up to 10 MB. Input and output: at most 8192 px per side and 12 megapixels. Working pixel buffers are bounded to 144 MB; browser decoding and encoding may need additional memory.
PNG?
Files stay in your browser. PNG export discards source metadata, color profiles and animation; only the first frame is used.