from a raster layer
Adds an easy way to style discrete rasters such as landuse classes
using the Paletted renderer. Just select the Paletted renderer,
pick a band, then hit the "Add Unique Values" button. The unique
pixel values will be fetched from the layer and a color assigned
to each using the currently selected color ramp.
Fix#14845
Sponsored by
- Stéphane Henriod
- Satelligence (http://satelligence.com/)
- Bird's Eye View (https://www.birdseyeviewgis.com/)
- + other anonymous backers
Previously the renderer required that pixel values followed
sequential numerical order. This refactor allows values to
be skipped, so that only certain color index will be rendered.
Some TIFF formulations, for example RGB TIFF with JPEG YCbCr compression, cannot
include a regular alpha band and instead use the GDAL mask band mechanism. Such
mask bands were ignored up to now. Now expose them as if they were alpha bands.
This is related to commit e0d38ba3f912b7ae6b34e66a44e529ec37394458. In case
we have to deal with an inconsitent raster where the nodata value is set to
a value not representable in the data type, ignore it. Otherwise, a NaN value
in a Byte raster would be cast as 0.
Currently if the source raster has no nodata value, the writer will still write
nan as the output nodata value, ignoring the flag that specifies if there is a
nodata value or not. On a raster with byte data type, this will cause
confusion on reading since the nodata value will be somehow cast as 0.
Make QgsRasterChecker check for nodata consistency between source and target, and
add a test file that shows the issue.
