Changes between Version 72 and Version 73 of Grass7/RasterLib
- Timestamp:
- Oct 13, 2022, 6:43:01 AM (22 months ago)
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Grass7/RasterLib
v72 v73 39 39 * Storage in '''tiles''' instead of by row 40 40 * Reasoning: Glynn said on the mailing list: "In most cases, single-level tiled storage will give you close to the same performance with a lot less complexity." 41 * The G3d library already implements a tile based approach with tile caching and tile file buffer for arbitrary read and write access, have a look at [http ://trac.osgeo.org/grass/browser/grass/trunk/raster3d/r3.in.ascii/g3d_volume_layout.png G3d tile layout]41 * The G3d library already implements a tile based approach with tile caching and tile file buffer for arbitrary read and write access, have a look at [https://grass.osgeo.org/grass-stable/manuals/raster3d_layout.png G3d tile layout] 42 42 * Function needed to check whether tiles are all null, or all the same value. 43 43 * What tile size should be used? Could be user/program specified, or standard value of something like 64x64. If there isn't a fixed value then there should be utility program that can convert tiled rasters to different tile sizes. … … 49 49 50 50 Notes about NULL file format 51 * Current cell_misc/null file size in GRASS GIS 7: The size of the cell_misc/<mapname>/null file depends only upon the number of rows and columns, not the data. It's one bit (null/non-null) for each cell, rounded to an integral number of bytes per row (i.e. the number of columns is rounded up to the nearest multiple of 8). 52 * Compression idea: see #2349 51 * Current cell_misc/null file size in GRASS GIS 7: The size of the cell_misc/ 53 52 === Directory structure === 54 53