Algorithm & Software Engineer | Computer Vision & 3D Depth | Evaluation & Benchmarking
Mask2PolyMin turns noisy segmentation masks into clean polygons with a minimal number of segments and sub-pixel corners.
Benchmarked against OpenCV's approxPolyDP: comparable IoU and Hausdorff distance, without corner-cutting bias.
pip install mask2polymin
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cv::convexHull spent most of its time in std::sort (O(n log n)), even though the hull algorithm itself is linear. A mentee from Kamatech replaced it with a bucket sort; I extended that into a dispatcher that picks the fastest method for each input:
- Counting sort when the coordinate range is small relative to the point count
- Radix sort (stable, 8-bit digits) when there are enough points per pass
std::sortotherwise
| Input | Speedup vs. std::sort |
|---|---|
| Noisy closed contours, 16β50,000 points | up to 6.4x |
| Dense random points, up to 50,000 | up to 66x |
| Tiny contours (16β32 points) | ~1x (no regression beyond noise) |
Issue #28846
PR #28868 (mentee's bucket sort; fixes and improvements by me)
PR #30196 (my follow-up: dispatcher, radix sort, float support)
Both PRs are under review.
How far can you trust camera-based depth? I compared stereo (OpenCV SGBM) and monocular depth (Depth Anything V2) against LiDAR ground truth on KITTI drives. Built during the 3D Ascension program by Think Autonomous.
- bev_from_depth: bird's-eye occupancy maps from each source, scored by IoU per distance band. Stereo reaches 0.59 IoU at 0β20 m but drops to 0.23 at 40β70 m; mono stays below 0.25.
- mono_vs_stereo_vs_lidar: per-frame RMSE and nearest distance per detected person or car, compared with LiDAR.
- π Expertise in computer vision, 3D/depth, computational geometry, combinatorics, graph and route planning
- π‘ Worked on Excel Copilot at Microsoft (2024β25)
- π Winner of RWTH Aachen Programming Competition for Students (sponsored by Sun Microsystems)
- Languages: Python, C, C++, C#, TypeScript
- Domains: Computer Vision, 3D/Stereo Depth, Computational Geometry, Graph Algorithms, Maps
- Frameworks & Tools: OpenCV, NumPy, PyTorch, Depth Anything, YOLO, pytest, Docker, Linux, Git
- πΌ LinkedIn

