Segmentation of an Image

Image segmentation covers techniques for splitting one image into several homogeneous regions. The Segmenter interface implements methods to segment a raster. The available methods in TerraAmazon are:

Input:

Output:

Select PROCESSING → RASTER PROCESSING → SEGMENTER in the main menu.


On the List of Layers select the raster layer to apply the segmentation.

Optionally use Filter By Name field giving part of the layer name to help find the layer in the list.

Press the the Next button to go to next step or the Cancel button to close the dialog.


Segmenter information

Type - Choose the method of segmentation and set the specific parameters required.

Region Growing Mean

Minimum segment size: A positive minimum segment size (pixels number ).

Similarity Threshold: Use lower values to merge only those segments that are more similar - Higher values will allow more segments to be merged - valid values range: positive values - default: 0.1.

Local Mutual Best Fitting : check in this box to activate best fitting.

Same Interaction Merges : check in this box to activate interaction merging.

Region Growing Baatz

Minimum segment size: A positive minimum segment size (pixels number ).

Similarity Threshold: Use lower values to merge only those segments that are more similar - Higher values will allow more segments to be merged - valid values range: positive values - default: 0.1.

Color Weight: The weight given to the color component, default: 0.75, valid range: [0,1].

Compactness Weight: The weight given to the compactness component, default : 0.5, valid range: [0,1].

Common Parameters:

Set No Data Value: If checked, no data value will be used as the no-data value for input rasters.

Select the Input Bands to be segmented by checking its box. For Baatz method, its is also possible to change Weight (The weight given to each band or an empty vector indicating that all bands have the same weight.)

Note: the bands weights sum must always be 1.

Preview - optionally click on the Preview button to check the segmentation of a small box of the image.

Press the Next button to go to next step.


Segmenter Advanced parameters information

Optionally, use this page to change default values of advanced parameters related with performance.

Block options:

Enable block processing: If checked, the original raster will be split into small blocks, each one will be segmented independently and the result will be merged (if possible) at the end.

Maximum block size: The input image will be split into blocks with this width for processing, this parameter tells the maximum block lateral size (width or height). The default behavior, the size will be defined following the current system resources and physical processors number.

Blocks Overlap Percent: block merging procedure will be performed. If the default value 0 indicates that no merge will be done.

Thread options:

Maximum threads number: The maximum number of concurrent threads. The default behavior is: automatically found. If default value 0 indicates that the application will calculate the best value based on your system.

Click on the Next button.


Output Raster information

Raster Info - First press the icon and inform the folder where the resulting file will be saved.

Name - inform the raster name.

Extra Parameters - if there are some.

Press the Finish button to save the resulting segmented raster or the Back button to go to the previous wizard page.