Visualization in QGIS

[wipfli]

Opening the osmviews.tiff file in QGIS shows all black with one white pixel at first:

steps

1. open QGIS
2. new project
3. Layer -> Add Layer -> Add raster layer...

[wipfli]

Take the logarithm to make it more visible what is going on:

steps

1. Raster -> Raster Calculator...
2. tick 'create on the fly..."
3. Use formula ln ("osmviews@1" + 1)

[wipfli]

Looks beautiful, like one of these night sky pictures...

[brawer]

The pipeline could directly store logarithmic values into the GeoTIFF. I tried this in 9952bb6, and it works quite well. But I wonder if it wouldn't be better to store the logarithm of the ranks. See #30.

[brawer]

As it turned out, computing the approximate rank of each raster pixel (#30) is easier if the input values have already been logarithmized. Therefore, I'll merge my changes of pull request #39. As a result, the output osmviews will (for now) be a GeoTIFF with logarithmic float32 values, as suggested by @wipfli on this thread; it looks nice when opened in QGIS. I'm still exploring #30, but the implementation will work on the current logarithmized float32 GeoTIFF as intermediate input.

[brawer]

The image now contains logarithmic values, so it looks nice when opened in QGIS.