Remove grey cast, whiten paper, sharpen text edges with unsharp masking. Measured sharpness gain shown.
Runs in your browser. No account, no upload, no watermark.
No. It improves readable-but-dull scans. Blurred-beyond-reading stays unreadable.
Laplacian edge-sharpness + paper whiteness, measured from pixels before/after.
2× smooths, doesn't add detail, and can exceed phone memory. 1× is safest.