kellyvv/openreshot

OpenReshot is a native iOS app that lets you take a regular photo and view or re-export it from a different angle, as if you had moved the camera before shooting. You select a photo, drag to shift the viewing angle within a fixed frame, and when you find a composition you like, tap to reconstruct and save a final image from that viewpoint. The effect is like having a second chance to reposition the camera after the photo was already taken. The app uses two main technologies to make this work. The first is 3D Gaussian Splatting, an AI technique that infers a three-dimensional representation of a scene from a single image. The second is Core ML, Apple's on-device machine learning framework, which runs the AI model entirely on the iPhone or iPad without sending anything to a server. Rendering uses Metal, Apple's graphics API, which keeps the real-time angle preview smooth. The AI model is not included in the app download to keep the file size small. On first run you download it from within the app's settings, from either ModelScope or Hugging Face as a backup. After downloading, the app compiles the model locally, and all subsequent processing runs on device. Reconstructions are cached so re-opening the same photo loads instantly without rerunning the AI. The app requires iOS 18 and a physical iPhone or iPad. Building from source needs Xcode 16, a Mac, and a tool called XcodeGen. The project was recently submitted to Apple's TestFlight beta program. OpenReshot is open-source under the Apache 2.0 license.