Graphics Programs Reference
In-Depth Information
After having generated the shaded-relief map, the graph has to be exported
onto a graphics fi le (Fig. 7.4). For instance, the fi gure may be written onto a
JPEG format with 70% quality level and a 300 dpi resolution.
print -djpeg70 -r300 srtmimage
The new fi le
srtmimage.jpg
has a size of 300 KB. The decompressed image
has a size of 16.5 MB. This fi le can now be imported to another software
package such as Adobe Photoshop.
7.6 Gridding and Contouring Background
The previous data sets were all stored in equally-spaced two-dimensional
arrays. Most data in earth sciences, however, are obtained on an irregular
sampling pattern. Therefore, irregular-spaced data have to be interpolated,
SRTM Data Set
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Longitude
Fig. 7.4
Display of the fi ltered SRTM elevation data set. The map uses the function
surfl
for generating a shaded-relief map with simulated lighting using interpolated shading and a
gray colormap in an overhead view. Note that the SRTM data set contains a lot of gaps, in
particular in the lake areas.
