README.md
1# GDAL Raster GeoTIFF Workflow
2
3```
4Build Tools: CMake/Ninja
5OS: Linux
6```
7
8### For installing GDAL:
9
10```
11sudo apt-get install python3.6-dev
12sudo add-apt-repository ppa:ubuntugis/ppa && sudo apt update
13sudo apt-get install gdal-bin
14sudo apt-get install libgdal-dev
15```
16
17### Dependencies:
18
19PNG: `sudo apt-get install libpng-dev`
20
21PCRE: `sudo apt-get install libpcre3 libpcre3-dev`
22
23PROJ: `sudo apt-get install libproj-dev`
24
25OBS! You may need to set `export LD_LIBRARY_PATH=/lib:/usr/lib:/usr/local/lib`.
26It is required for libproj.so to be found into /usr/local/lib/. You can also fix
27this by typing `locate libproj.so` which will give you
28<the_absolute_libproj.so_path> and then `cp <the_absolute_libproj.so_path>
29/usr/local/lib/`.
30
31### Initializing GDAL submodule:
32
33`git submodule add https://github.com/OSGeo/gdal/tree/master/gdal`
34
35### Building GDAL statically
36
37GNUmakefile from gdal/gdal can handle building the static library.
38
39`cd gdal/gdal && make static-lib`
40
41`cd ../.. && mkdir lib`
42
43`cp gdal/gdal/libgdal.a lib/`
44
45OBS! The file is huge! It may take a while.
46
47### For testing:
48
49`mkdir build && cd build`
50
51`cmake .. -G Ninja`
52
53`ninja`
54
55`./raster <your_absolute_tiff_file_path>`
56
57## About the project
58
59GDAL is a translator library for raster and vector geospatial data format. The
60project consist in rastering a GeoTIFF file format using GDAL functionalities
61and sandboxed methods.
62
63## Implementation
64
65*Sandboxing...*
66
67The purpose of sandboxing is to limit the permissions and capabilities of
68library’s methods, in order to secure the usage of them. After obtaining the
69sandbox, the functions will be called through an Sandbox API (being called api
70in the current test) and so, the operations, system calls or namspaces access
71may be controlled.
72
73*Raster process...*
74
75Useful functions from the `gdal.h` header are added to the SAPI library built
76with CMake.
77
78One .tiff file is manipulated with GDALOpen functionality, which extracts a
79pointer to the data set containg a list of raster bands, all pertaining to the
80same area. Metadata, a coordinate system, a georeferencing transform, size of
81raster and various other information are kept into the data set that corresponds
82to the image.
83
84To create an array containing the image information, the dimentions needed are
85extracted using some specific GDAL(X/Y)Size functions applied to the block.
86GDALRasterBand function takes care of data type conversion, one more step
87following: placing the converted data (with RasterIO method) into the created
88and well allocated structure.
89