EclipseStack

Concept

Alignment tool for solar eclipse HDR composites. Takes hundreds of RAW frames captured during totality and produces sub-pixel-aligned output ready for HDR stacking in PixInsight. Addresses tracker drift by combining solar disk detection (computer vision) with temporal drift modeling from EXIF timestamps — the constant drift rate fills alignment gaps between confident frames.

Features

• Sony RAW (.ARW) file decoding and processing
• Automatic solar disk and moon silhouette center detection
• Temporal drift modeling using EXIF timestamps for frame-to-frame extrapolation
• Solar flare detection as secondary anchors for sub-pixel and rotational alignment
• Web UI for visualizing drift paths, reviewing alignments, and seeding confident frames
• Batch export to TIFF/FITS for PixInsight

Quick Facts

What This Is

EclipseStack is a Rust-powered utility (with a web-based UI) specifically designed to align hundreds of RAW solar eclipse images taken during totality. It addresses the challenge of tracker drift by combining image feature detection (solar disk and flares) with temporal extrapolation based on EXIF data. The goal is to produce a perfectly aligned set of frames ready for HDR stacking in professional tools like PixInsight.

Core Value

Enable high-fidelity HDR solar composites by providing sub-pixel alignment of eclipse frames through a combination of computer vision and temporal drift modeling.

Context & Constraints

• Input: Hundreds of Sony RAW files (.ARW).
• Subject: Total solar eclipse (totality), centered disk, visible solar flares.
• Challenge: Subtle tracker drift over time; lack of background stars for traditional alignment.
• Technology: Rust (core processing), Web-based UI (potentially via Tauri or a web-tech stack), EXIF data for drift modeling.
• Output: Aligned frames (likely TIFF/FITS) compatible with PixInsight.

Requirements

# Validated

(None yet — ship to validate)

# Active

• RAW Processing: Extract and decode Sony RAW files for processing.
• Disk Detection: Automatically locate the center of the solar disk/moon silhouette in each frame.
• Temporal Drift Modeling: Use EXIF timestamps to model and extrapolate tracker drift across frames.
• Feature-Based Alignment: Identify and use solar flares as secondary anchors for sub-pixel and rotational alignment.
• Interactive UI: A web-based interface to visualize the drift path, review alignments, and manually “seed” confident frames.
• Batch Export: Export aligned frames in a format optimized for PixInsight (TIFF/FITS).

# Out of Scope

• HDR Stacking: The actual stacking/merging logic (deferred to PixInsight).
• General Astrophotography: This tool is specifically optimized for solar eclipse geometry.
• ML Alignment (v1): Machine learning-based feature detection is deferred to v2.

Key Decisions

Last updated: Friday 13 February 2026 after initialization