PDF Repair Tool

Purpose & User Intent: The tool targets professionals who rely on stable PDFs for legal, financial, and research workflows. When a file fails to open, shows errors, or contains garbled content, users need a systematic repair process rather than recreation. It analyzes the PDF structure, identifies missing or damaged objects, and attempts reconstruction while preserving readable content and as much original formatting as possible. It avoids altering non‑PDF metadata and external references except where necessary to restore integrity.
Core Logic & Features: Required features include PDF parsing, structural validation, cross-reference (xref) repair, object reconstruction, and integrity checks. Optional/advanced features include font mapping, image re-linking, incremental repair, and form field reconstitution. This supports recovery across invoices, reports, contracts, and scanned documents with mixed content.
Inputs & Outputs: Inputs include input_pdf (PDF file, required, sample: invoice.pdf, validation: application/pdf, max_size: 50MB), repair_mode (basic|advanced, optional), retain_fonts (boolean, optional), version_target (PDF spec, optional). Outputs include repaired_pdf (PDF file, mime: application/pdf).
Algorithms & Calculations: The tool uses deterministic parsing of the PDF object graph, validates and refreshes the cross-reference table, reconstructs corrupted streams and indirect objects, and applies heuristics to re-link fonts and images when recoverable. It preserves non-PDF metadata where possible and validates final compatibility with common readers.
Error & Edge Cases: If input is password-protected, severely corrupted, or missing critical objects, the repair may produce a partial output or fail with diagnostic data. In such cases, the system returns explicit error signals and guidance on remediation.
Industry/Region & Localization: Aligns with ISO 32000-1 standards; suitable for global use with multilingual content; encryption handling follows standard rules when permissible.
Assumptions & Exclusions: Assumes access to non-password-protected input; excludes non-PDF formats, unrelated metadata restoration beyond structural corrections, and complete guarantee of content accuracy when data is irrecoverable.