Levels & Auto-Contrast

Choose an image

or drag & drop an image here

Images are processed in your browser. Nothing is uploaded.

Black (0-255)

White (0-255)

Gamma (0.1-3.0)

Preview (after levels/gamma)

Luma histogram (Y ≈ 0.2126R + 0.7152G + 0.0722B)

Black / White: Remap input intensities so values ≤ Black become 0 and ≥ White become 255. Values in-between are stretched.
Gamma: Mid-tone curve. <1.0 brightens mids; >1.0 darkens mids; 1.0 is neutral.
Auto: Finds low/high from the luma histogram with ~1% clipping on each end; sets Black and White, gamma = 1.0.
Histogram: Left = shadows, right = highlights. Use it to see where data is clipped or compressed.
Workflow: Load image → click Auto → fine-tune Black/White/Gamma → Download.
Note: This tool edits pixels in your browser only; no files are sent to any server.

Formula (per channel): t = clamp((x - B) / (W - B), 0, 1); out = 255 · t^(1/γ).

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