Image Comparison Ranker

A fast, keyboard-driven web app for ranking large image collections using Elo-rated triplet comparisons.

The Problem

You have hundreds or thousands of images and need to find the best ones. Comparing them one-by-one is tedious. Rating them 1-5 stars is inconsistent. You need a better way.

The Solution

This tool shows you 3 images at a time. Pick your favorite. An Elo rating system (like chess rankings) handles the math, surfacing your best images to the top with surprisingly few comparisons.

Key features:

• Triplet comparisons — Easier than absolute ratings; just pick the best of three
• Elo scoring — Images that beat strong images rise faster
• Swiss-style pairing — Efficiently matches similar-ranked images to refine rankings quickly
• Rejection culling — Quickly eliminate obvious losers to reduce total comparisons needed
• Undo support — Fix mistakes with one keypress
• Keyboard-driven — 1/2/3 to pick, Q/W/E to reject, ← to undo
• Automatic organization — Sort images into ranked folders when done

Use Cases

• Curating AI-generated images (Stable Diffusion, Midjourney, ComfyUI, etc.)
• Selecting best photos from a shoot
• Ranking reference images for art projects
• Sorting any large image collection by subjective quality

How It Works

1. Point it at a folder of images
2. Compare triplets until the ranking stabilizes
3. Click "Organize" to sort images into ranked folders

For N images, you'll need roughly N×2 comparisons to get a reliable ranking — far fewer than comparing every possible pair.

Installation

pip install flask
python compare.py
# Open http://localhost:5000

Also Included

app.py — A simpler thumbs-up/thumbs-down ranker for quick sorting into quality tiers.