Request for Changes-26: MPI Image File Writer
[Request for Changes - 24] MPI Image file writer
- Author: Rémi Cresson
- Submitted on 11.02.2016
- Proposed target release 5.4
Provide a parallel image file writer, which use MPI-IO to write one image with multiple processing nodes simultaneously
Use OTB on HPC architectures
Classes and files
otbMPIImageFileWriter.h (or something like this?) otbMPIImageFileWriter.hxx otbMPIHelpers.h (containing some bridge definitions between OTB and MPI, like data types.)
The actual writer writes only GeoTiffs. It relies on the SPTW (Simple Parallel Tiff Writer)  developed by David Matthew Mattli. I have modified the SPTW to make it writing stripped images (only tiled writing was implemented). Maybe it could be convenient to refactor SPTW into the writer class and add David to the contributor list.
Tests could consist in comparing one image writed with the original otb::ImageFileWriter to images produced with the parallel image file writer using different tiling scheme, strategies, etc.
List remaining open issues if any, and additional notes.