How can I reduce the size of a raster mosaic made by the mosaicker. The geotiff mosaic is about twice the size of the edge matched tiles - made by Pix4D.

Hi @tinloes, I don't think mosaic process itself affects the destination file size. The GeoTiff format support some compression methods. How about applying one of them?

Note: If the source format was GeoTIFF and the source data has been compressed, possibly you have to remove geotiff_compression_method attribute before writing. See also this Q&A;: Convert Packbits geotiff to lzw