Process
Introduction
This is Stage 4 of the Research Gate. This stage focuses on ordering and analyzing source media streams to extract technical data and convert raw footage into usable assets. This foundation is critical for the accuracy of the entire project.
CRITICAL: Never alter original source files. All manipulations (sharpening, un-distorting) must be done on duplicates/proxies. Log every filter & setting applied for transparency.
Ingest
Bring source media into the working tree and log what you do.
Analysis
Assess optics, artifacts, and metadata.
Processing
Enhance images and align footage temporally.
Source Intelligence (Analysis)
Ingest
The vault, the hash and custody log, and the working-copy layout live in Preserve & Store. This stage only brings source media into that working tree and records what it does.
Segmentation
Split the working copies into the segments the analysis needs (per camera, per event, per angle), extract frame and still sequences where the work requires them (e.g., with FFmpeg[1]), and group the working set by source device or origin (e.g., "Source A - CCTV North"). Reserve a directory for each clip set before it exists, so the segments land in the right place of the Preserve & Store layout: Footage, Image_Seq, Stills, Work per source.
Technical Assessment (See Camera Fundamentals for Investigation)
Source characterization (optics, artifacts, geometry) is shelved for now: it was cut from Collect while that page is trimmed to a scaffold, and it will come back when the course needs it.
Check for Metadata / Metadata Extraction (See Metadata Extraction)
Metadata handling (EXIF/XMP, lens and sensor estimates) is shelved for the same reason: it was cut from Collect along with the technical assessment.
Temporal Alignment (See video alignment)
Sync all video footage to a single master real-world timeline (e.g., "Event Time 12:00:00") using metadata timestamps or visual anchors (e.g., a specific flash of light visible in all cameras).
Further Processing
Image Enhancement (Working Copies):
Create separate "Work Files" for selected images. See if lens distortion can be countered, reduce blur (sharpening), upscale, or adjust contrast to reveal stronger perspective lines.
Documentation for Methodology
What to document during Ingestion & Processing
In Your Method Section
Describe the chain of custody for your digital assets. "All source material was hashed (SHA-256) upon receipt and stored in a read-only vault. Working copies were generated for analysis. Metadata was extracted using [Tool Name] to establish camera parameters."
In Your Decision Log
Record the following:
- Hash values of original files.
- Any enhancements applied to working copies (e.g., "Applied unsharp mask to Frame 405 to read license plate").
- Estimated camera parameters when metadata was missing.
- Synchronization points used for temporal alignment.
Verification
"Checksums of working copies were verified against the vault log to ensure data integrity."
Summary
In this phase, we have established a secure and organized foundation for the investigation. By strictly separating the vault from working copies and systematically analyzing the technical properties of each source, we ensure that all subsequent reconstruction steps are built on verified data.
Key Takeaways:
- Preservation: Always keep a pristine, hashed copy of original evidence[2].
- Organization: Use a consistent folder structure and naming convention.
- Analysis: Understand the technical limitations (distortion, artifacts) of your footage before modeling.
- Alignment: Sync multiple sources to a single timeline early in the process.
Resources
- Research Gate — Stage 4 of the gate: this page
- Analyze — next stage: ground truth, uncertainty, and the decision log