Classify image using thresholds

Use the Classify image using thresholds block to create a thematic band from a numeric band. For example, you can use this block to group elevation data into discrete height ranges.

Click on the cog icon to create a new thematic band.

Use band

Select the numeric band to use as the basis for your new thematic band.

Save as new band called

Choose a name for the new thematic band.

New classes

By default, the new band contains two classes. To add a new class, hover over the class that you want to split, and click on the plus icon that appears at the end of the row.

When you add a new class the range of the threshold gets divided into two equal ranges. You can adjust each range as needed.

Value

Choose a unique value for each class. 

Colour

Click on the colour swatch to change the hex code assigned to the class. This is used when outputting map layers.

Description

Add a description to label each class.

Threshold

For each class, the range is from the value shown above the row, to the value shown below the row. Thresholds must be set in sequence from lowest to highest.

The lowest and the highest ranges do not need to have lower/upper values. For example, if you want your first class to include every number below zero, set ‘0’ as the top of the range, and leave the box for the bottom of the range empty.

Values that fall outside of the ranges of the classes will be masked out, and are transparent when outputted as map layers.