Parametrize pixel values to fit a desired range

You must know the actual range (computing it could take too much EE memory capacity)



In [1]:

    
import ee
ee.Initialize()



In [2]:

    
from geetools import tools



In [3]:

    
import ipygee as ui



In [4]:

    
i = ee.Image('COPERNICUS/S2/20181122T142749_20181122T143353_T18GYT').select('B1')



In [5]:

    
Map = ui.Map()



In [6]:

    
Map.show()



In [7]:

    
Map.addLayer(i, {'min':0, 'max': 6000}, 'Original')

As values in Sentinel 2 go from 0 to 10000, parametrize values to be between 0 and 1



In [8]:

    
parametrized = tools.image.parametrize(i, (0, 10000), (0, 1))



In [9]:

    
Map.addLayer(parametrized, {'min':0, 'max': 0.6}, 'Parametrized')

BEFORE



In [10]:

    
tools.image.getValue(i, i.geometry().centroid(), 10, 'client')









    Out[10]:





{'B1': 4712}

AFTER



In [11]:

    
tools.image.getValue(parametrized, i.geometry().centroid(), 10, 'client')









    Out[11]:





{'B1': 0.4712}

Range can be switched



In [12]:

    
switch_parametrized = tools.image.parametrize(i, (0, 10000), (1, 0))

AFTER

1 - 0.4712 = 0.5288



In [13]:

    
tools.image.getValue(switch_parametrized, i.geometry().centroid(), 10, 'client')









    Out[13]:





{'B1': 0.5287999999999999}



In [ ]: