phash

The Thumbnails Had Been Drifting: Catching Image-Asset Regressions with pHash and SSIM in Your Agent Workflow

After letting an agent rewrite an image pipeline, visual quality can quietly slip in ways tests never catch. This guide shows how to measure that drift with two numbers — pHash and SSIM — and block it in CI, from threshold calibration to a ready-to-run gate script and Antigravity integration.