Smooth Isolines

A generated isoline map in traditional analogical methods produces isolines with visual smooth properties. When isolines are obtained in digital systems from regular rectangle grids or irregular triangle grids, it is observed sharp corners. A smooth isoline method creates curve format to that data.

Catmull-Rom Spline was selected to smooth isolines due to its control point interpolation properties and calculation simplicity.

Select PROCESSING → DTM PROCESSING → SMOOTH ISOLINES in the main menu.


Input Parameters:

Layer Name: select the layer.

Simplification Parameters:

Target Scale: enter the scale value and click on the OK button beside the field.

Simplification Factor: this value will be used to do an input line filtering. Enter the wanted value in meters.

Maximum Distance: this value will define distance among simplified line points. Enter the value in meters.

Simplify output: click on this box if after lines being smoothed they will pass through Douglas_Peuckher simplification method using tolerance for simplification.

Repository: Click on the icon to save the result in a shape file or click on the icon to save it in a data source.

Output Layer Name: enter the name of generated image.

Join lines: click on this box if input layer has fragmented lines to be joined automatically.


Click on the OK button.