hubflow reclassify "unclassified" class name

[Benjamin Jakimow]

hubflow.core.Classification.reclassify() does not allow to use another name for unclassified.

Let pathSrc be a classification raster with 3 classes (values from 0 to 2), then this should allow to reclassify the raster to 2 classes (values 0 or 1, class names "No class" or "Class B").

        import hubflow.core
        classification = hubflow.core.Classification(pathSrc)
        # do not add the unclassified class
        newNames = ['No Class', 'Class B']
        newDef = hubflow.core.ClassDefinition(names=newNames)

        classification.reclassify(filename=pathDst,
                                  classDefinition=newDef,
                                  mapping={0:0,1:1,2:1})
        ds = gdal.Open(pathDst)
        band = ds.GetRasterBand(1)
        classNames = band.GetCategoryNames()
        self.assertEqual(newNames, classNames)

List classNames will return ['unclassified', 'No Class', 'Class B'] instead of ['unclassified', 'Class B']. Using unclassified implicitly breaks with GDAL API standard that allows to specify the class name corresponding to class value = 0.

[Benjamin Jakimow]

Related to this a test case:

import unittest
from unittest import TestCase
from enmapbox.gui.utils import *
APP = initQgisApplication()

class BugTests(TestCase):


    def test_reclassify(self):
        import hubflow
        import hubflow.core
        classA = TestObjects.inMemoryClassification()
        self.assertIsInstance(classA, gdal.Dataset)
        print('old names: {}'.format(classA.GetRasterBand(1).GetCategoryNames()))
        pathSrc = classA.GetFileList()[0]
        pathDst = '/vsimem/testoutput.tif'
        classification = hubflow.core.Classification(pathSrc)
        newNames = ['Not specified', 'Class X']
        lookup = {0:0,1:1,2:1}
        # do not add the unclassified class
        newDef = hubflow.core.ClassDefinition(names=newNames)
        print(newDef)
        classification.reclassify(filename=pathDst,
                                  classDefinition=newDef,
                                  mapping=lookup)

        dsNew = gdal.Open(pathDst)
        self.assertIsInstance(dsNew, gdal.Dataset)
        writtenNames = dsNew.GetRasterBand(1).GetCategoryNames()
        self.assertIsInstance(writtenNames, list)
        self.assertListEqual(writtenNames, newNames, msg='Names not equal: \nshould be:{}\nwritten: {}'.format(newNames, writtenNames))

if __name__ == "__main__":

    unittest.main()

[Andreas Janz]

In the ClassDefinition, the no data class (label=0) is not considered as a normal class. I added a special setter for the no data name and color and changed the test case accordingly:

        classification = Classification.fromArray(array=[[[0, 1, 2]]], filename='/vsimem/c.bsq')
        newNames = ['Class X']
        mapping = {0: 0, 1: 1, 2: 1}
        newDef = ClassDefinition(names=newNames)
        newDef.setNoDataNameAndColor(name='Not specified', color=Color(128, 128, 128))
        print(classification.classDefinition())
        print(newDef)
        reclassified = classification.reclassify(
            filename='/vsimem/c2.bsq', classDefinition=newDef, mapping=mapping)

        print(reclassified.dataset().band(0).categoryNames())
        print(reclassified.dataset().band(0).categoryColors())

Prints:

#!

['Not specified', 'Class X']
[(128, 128, 128, 255), (186, 71, 78, 255)]

[Andreas Janz]

Removing component: HUB (automated comment)