US 2025/0315981 A1, “Imaging Systems and Methods for Dimension Measurement Independent of Laser Alignment,” published today. It’s the patent application behind FishSense-Lite, filed by the University of California with Ryan Kastner, Kyle Hu, Nathan Hui, Brice Semmens, and me as inventors.
The title gets at the key idea. Laser rangefinding usually depends on a laser that is precisely lined up with the camera, and building a mount that holds that alignment, underwater, on a camera a volunteer bought off the shelf, is hard. So we don’t try. Instead, we calibrate wherever the laser happens to be pointing relative to the camera, and use that calibration to turn the laser spot’s position in each photo into a distance to the fish. Once you know the distance, the pixels between two points on the fish, like its snout and tail fork, become a real length.
That’s what lets FishSense-Lite get away with a consumer dive camera, a dive laser, and a 3D-printed mount.
You can read the full application here or on Google Patents. It was filed April 7, 2025 (Application No. 19/172,386), claiming priority to a provisional application from April 5, 2024.