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Updated gdal tutorial to include comments.

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Marvin Smith
2015-01-17 19:28:58 -08:00
parent 9a1a9d9aff
commit 91fbe00caa
3 changed files with 33 additions and 31 deletions
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doc/tutorials/highgui/raster-gdal/raster_io_gdal.markdown
+8 -8
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@@ -3,7 +3,7 @@ Reading Geospatial Raster files with GDAL {#tutorial_raster_io_gdal}
Geospatial raster data is a heavily used product in Geographic Information Systems and
Photogrammetry. Raster data typically can represent imagery and Digital Elevation Models (DEM). The
standard library for loading GIS imagery is the Geographic Data Abstraction Library (GDAL). In this
standard library for loading GIS imagery is the Geographic Data Abstraction Library [(GDAL)](http://www.gdal.org). In this
example, we will show techniques for loading GIS raster formats using native OpenCV functions. In
addition, we will show some an example of how OpenCV can use this data for novel and interesting
purposes.
@@ -13,8 +13,8 @@ Goals
The primary objectives for this tutorial:
- How to use OpenCV imread to load satellite imagery.
- How to use OpenCV imread to load SRTM Digital Elevation Models
- How to use OpenCV [imread](@ref imread) to load satellite imagery.
- How to use OpenCV [imread](@ref imread) to load SRTM Digital Elevation Models
- Given the corner coordinates of both the image and DEM, correllate the elevation data to the
image to find elevations for each pixel.
- Show a basic, easy-to-implement example of a terrain heat map.
@@ -54,9 +54,9 @@ signed shorts.
Notes
-----
### Lat/Lon (Geodetic) Coordinates should normally be avoided
### Lat/Lon (Geographic) Coordinates should normally be avoided
The Geodetic Coordinate System is a spherical coordinate system, meaning that using them with
The Geographic Coordinate System is a spherical coordinate system, meaning that using them with
Cartesian mathematics is technically incorrect. This demo uses them to increase the readability and
is accurate enough to make the point. A better coordinate system would be Universal Transverse
Mercator.
@@ -94,8 +94,8 @@ Below is the output of the program. Use the first image as the input. For the DE
the SRTM file located at the USGS here.
[<http://dds.cr.usgs.gov/srtm/version2_1/SRTM1/Region_04/N37W123.hgt.zip>](http://dds.cr.usgs.gov/srtm/version2_1/SRTM1/Region_04/N37W123.hgt.zip)
![](images/gdal_output.jpg)
![Input Image](images/gdal_output.jpg)
![](images/gdal_heat-map.jpg)
![Heat Map](images/gdal_heat-map.jpg)
![](images/gdal_flood-zone.jpg)
![Heat Map Overlay](images/gdal_flood-zone.jpg)