Show HN: Sarpro – 5–20× faster Sentinel‑1 GRD → GeoTIFF/JPEG

I’ve shipped a big performance upgrade to Sarpro, an open‑source Rust tool for converting Sentinel‑1 SAR GRD products into GeoTIFF or JPEG. Since my initial post [here](https://news.ycombinator.com/item?id=44872768), Sarpro now avoids full‑resolution I/O when you only need a smaller output and performs reprojection in‑process without writing giant temporary files.

Highlights: - Target‑size reads and single‑step warp: read/warp directly to the final output size instead of loading full‑res first. This cuts I/O and memory by 5–20× for small outputs. - Reprojection to any CRS: `--target-crs EPSG:xxxx` with in‑process gdalwarp via VRT (no temp GeoTIFF). Resampling: nearest/bilinear/cubic/lanczos. - Faster autoscaling: O(N) histogram‑based percentiles replace O(N log N) sorting. - Batch + GUI: both now honor reprojection/resampling in batch mode. - Performance: on a modern laptop (M4Pro12), scaling a dual‑band ~400–500MP GRD to 2048 px typically completes in ~1–2 s; no‑warp downsamples can be sub‑second. Full native warps remain tens of seconds as expected.

Features: - CLI, GUI, and Rust API - Synthetic RGB from polarization pairs, robust autoscaling, optional padding - TIFF and JPEG outputs with georeferencing/sidecars, metadata emission

I’d love feedback from the RS/EO community: more RGB presets, additional processing modes, tiling for ML, and cloud pipeline integrations.

Links: - GitHub: `https://github.com/bogwi/sarpro` - Previous HN thread: [Show HN post](https://news.ycombinator.com/item?id=44872768)