[WIP] Multiprocessing interpolation and reprojection

[vschaffn]

Resolves #648.

Description

This PR introduces raster interpolation and reprojection using multiprocessing to optimize memory usage and improve performance.

Code changes

• Multiprocessing interpolation : The function multiproc_interp_points leverages multiprocessing to create a separate process for each point to be interpolated. For each point, the function calculates the smallest possible raster window to open based on the interpolation method and point coordinates, and use the raster.crop method to open the window. The raster.interpolate method is then applied to the cropped raster window, allowing for efficient interpolation without loading the full raster into memory.
• Multiprocessing reprojection: The function multiproc_reproject utilizes raster tiling (see Implement Tiling for Multiprocessing #652) to perform multiprocessing-based reprojection. A separate process is created for each tile of the raster. Each process opens the corresponding tile using the raster.icrop method, calculates the bounds of the reprojected tile, snaps the bounds to the target reprojected grid, and reprojects the tile using the raster.reproject method. The reprojected tiles are written separately to disk, with safeguards in place to prevent data overwriting.

Tests

• Unit tests have been implemented to verify the correctness of both multiproc_interp_points and multiproc_reproject. The test results are compared against the behavior of the raster.interpolate and raster.reproject methods to ensure consistency.

Note:

Currently, there are some tile alignment issues when performing reprojection operations that involve more than just translation. Further investigation is required to address these challenges.

Difference between tiled reprojection and classic reprojection (exploradores_aster_dem):

• Changed CRS: