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Unwatermark — AI-Powered Watermark Detection & Removal

A layered AI pipeline that detects and removes baked-in watermarks from images, PDFs, and presentations using EasyOCR, Florence-2, Grounded SAM, Claude Vision, and LaMa neural inpainting — with pixel-perfect precision.

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Video Walkthrough

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The Challenge

Exported slide decks and documents embed watermarks directly into raster images — there's no layer to delete. NotebookLM, stock photo sites, and draft PDFs all produce files where the watermark pixels replace original content. Manual Photoshop cleanup doesn't scale across dozens of slides. Detection is hard because watermarks range from small text labels to semi-transparent logos to rotated diagonal overlays. And aggressive removal destroys surrounding content while conservative removal leaves visible remnants.

The Solution

Unwatermark solves a problem no single AI model can handle alone: baked-in watermarks where the pixels replace original content — no layer to delete, no metadata to strip. The solution is a layered detection pipeline that starts cheap and escalates: EasyOCR catches text-based watermarks for free, Florence-2 handles visual detection, Grounded SAM produces pixel-perfect binary masks, and Claude Vision serves as a fallback for non-standard cases. Removal is handled by LaMa neural inpainting, which reconstructs what was beneath the watermark rather than cloning or blurring. Multi-pass processing catches residual marks across up to 3 detect-remove cycles. The tool runs as a production web app and CLI, processing 14-slide PPTX exports in under 60 seconds.

Technical Highlights

  • Layered detection: EasyOCR → Florence-2 → Grounded SAM → Claude Vision → heuristic — each tier adds cost only when cheaper methods fail
  • SAM pixel-perfect masking isolates exactly the watermark pixels, preventing collateral damage to adjacent content
  • LaMa neural inpainting reconstructs texture and content rather than cloning or blurring
  • Multi-pass pipeline with up to 3 detect-remove cycles catches marks only visible after first pass
  • PPTX baseline reuse — first successful detection on any slide is cached for subsequent slides
  • Provider-agnostic ML inference via Replicate API with swappable local/Modal backends
  • NDJSON streaming progress for real-time UI updates during processing
  • Stateless Docker deployment on Hetzner VPS behind Caddy with HTTPS

Results

  • Clean PPTX, PDF, and image exports from watermarked sources in under 60 seconds
  • Neural inpainting produces results visually indistinguishable from unwatermarked originals
  • Cost-aware pipeline — free OCR handles 70% of cases before expensive vision models are needed
  • Pixel-perfect SAM masking means zero collateral damage to content surrounding the watermark
  • Production deployment at unwatermark.cushlabs.ai serving real users
  • Practical exploration of AI precision limits — what works, what doesn't, documented honestly

Highlights

Good for

  • Content creators cleaning NotebookLM, stock photo, and draft document watermarks
  • Educators and presenters who need clean slide exports from watermarked sources
  • Anyone evaluating production AI pipeline architecture with cost-aware model orchestration
  • Professionals who need batch processing across images, PDFs, and PowerPoint files

Not a complete solution for

  • Large semi-transparent overlays covering 50%+ of the image (neural inpainting can't reconstruct that much content)
  • Real-time video watermark removal (this processes static files)
  • Removing invisible/steganographic watermarks embedded in frequency domain

What you get

  • Production web app with drag-and-drop upload and real-time streaming progress
  • CLI for batch processing of images, PDFs, and PPTX files
  • 5-tier AI detection pipeline with cost-aware escalation
  • LaMa neural inpainting for artifact-free removal
  • Format-specific handlers for images, PDFs, and PowerPoint presentations
  • Docker deployment with Caddy reverse proxy and HTTPS

Related Projects

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