PyMapStitcher 3 is a desktop application for downloading, stitching, and exporting very large satellite map areas as GeoTIFF/BigTIFF files. The software supports GPU acceleration with NVIDIA CUDA and CuPy, direct GeoTIFF georeferencing, WebView-based map selection, and high-performance tile processing for large-scale mapping workflows.

PyMapStitcher3 uses a streaming and tile-based processing workflow to keep memory usage low. Instead of loading the entire map into RAM, tiles are downloaded, processed, and written directly to the output GeoTIFF/BigTIFF in small chunks. Temporary image data is released immediately after use, allowing PyMapStitcher3 to create extremely large georeferenced mosaics while maintaining a relatively small and stable memory footprint. The program and this work was made with the help of AI.