Feature Request: Duplicate/Blank Page Detector

[Rafid92]

Motivation

Users working with scanned or merged PDFs often end up with blank pages or accidental duplicates (from re-scanning, merging multiple files, etc.). Manually scrolling through every page to find these is tedious. An auto-detector that flags them would pair naturally with the existing Remove Pages feature, letting users clean up a document in a couple of clicks instead of a manual page-by-page review.

Acceptance Criteria

• System scans all pages of a loaded PDF and flags blank pages (no/negligible text or image content)
• System detects duplicate pages (identical or near-identical content) and flags them
• Flagged pages are visually marked in the page thumbnail/navigation panel
• User can review flagged pages before removal (no auto-delete without confirmation)
• One-click action to send all flagged pages to the Remove Pages feature
• User can dismiss/unflag a page if it's a false positive
• Works on multi-page documents without noticeable UI lag

Technical Notes

• Blank detection: check extracted text length + rendered pixel variance/whitespace ratio
• Duplicate detection: hash page content (text hash and/or perceptual image hash) and compare across pages; consider a similarity threshold rather than exact match only
• Integrate with existing page thumbnail/navigation panel for flag indicators
• Should run as a background/async scan so it doesn't block the UI on large documents

Priority

enhancement pdf page-management