Announcing the release of the new Semi-Automatic Classification Plugin

I am very pleased to announce the release date of the new Semi-Automatic Classification Plugin (SCP) version 6 (codename Greenbelt).
This new SCP version, which is compatible with QGIS 3 only, will be released on the:
 22 January 2018

The Semi-Automatic Classification Plugin (SCP) version 6 has the codename Greenbelt (Maryland, USA) which is the location of the NASA’s Goddard Space Flight Center that had a key role in Landsat satellite development and will lead the Landsat 9 development of the space and flight segments (Landsat 9 to be launched in 2020).

Main interface

Please watch the following video that illustrates the main features of this new version.

I have redesigned Main interface that contains the SCP tools.
In addition, I have implemented a profound change to the SCP core, which is the ability to define multiple band setsthis opens many possibilities for new tools that can exploit the combination of bands which I tried to include in SCP 6.
The new Main interface is divided in several sections that are accessible through a menu at the left side.These sections are:
  • Band set: definition of the input image used for classification and other tools;
  • Basic tools: general tools for running SCP, such as the RGB color composite;
  • Download products: tools for searching and downloading free images such as Landsat, Sentinel-2, ASTER, and MODIS;
  • Preprocessing: tools for preprocessing images before classification;
  • Band processing: tools for processing images;
  • Postprocessing: tools for postprocessing images after the classification;
  • Band calc: tools for easing raster calculation also using the band set;
  • Batch: tool for automating the SCP processes;
  • Settings: advanced options of SCP.

Image input in SCP is named band set. One of the main changes of SCP 6 is the ability to define multiple band sets as input for classification and other tools.
Band sets are identified by numbers and the active band set (i.e. highlighted with a bold green name) is used as input for the tools in SCP dock. It is possible to change the classification input just by selecting the corresponding band set tab. In a few clicks we can compare the classification previews of different images without the need to create different QGIS projects.

Multiple band sets

Images can be loaded directly from SCP or use the rasters already loaded in QGIS.
The Band set definition is saved with the QGIS project.
The ability to define multiple Band sets eases the comparison between several images and processes such as raster mosaic.

In SCP 6 I have added a new tool which allows for the clustering using K-means or ISODATA algorithms.

Clustering tab
The K-means method is based on the calculation of the average spectral signature of clusters.
The ISODATA (Iterative Self-Organizing Data Analysis Technique) method is similar to K-means but with the additional steps of merging clusters having similar spectral signatures and splitting clusters having too high variability.
With SCP 6 it is possible to create the seed signatures in several ways: from pixels randomly selected in the image; using the signature list; or considering the minimum and maximum band values.

Spectral distance is a new tool that exploits the possibility to create multiple band sets.
This tool allows for calculating the spectral distance between every corresponding pixel of two band sets. The output is a raster containing the spectral distance of each pixel, calculated as Minimum Distance or Spectral Angle Mapping.
Also, a threshold can be defined for creating a binary raster of values below and above this threshold.
This tool can be very useful for assessing land cover change in an automatic way.

Spectral distance tab

I have updated the interface for downloading free products such as Landsat, Sentinel-2, ASTER, MODIS and the new addition Sentinel-3.

Download products

The new interface allows for the search and download of several free products, and in particular it is possible to download and preprocess Sentinel-2 Level 2A and Sentinel-3 OLCI images.
It is possible to display the preview of the selected item inside the interface, as an alternative to loading the preview inside the map.
In addition, the product list can be imported and exported, as well as saved within the QGIS project.

Download products new interface

The Sentinel-3 tab has been added to the Preprocessing tools, allowing for the direct conversion to reflectance.

Sentinel-3 conversion
I have added two preprocessing tools that exploit the new ability to create multiple band sets.
The tool Cloud masking allows for the creation of an output masked band for each band of a band set, based on the values of a raster mask. 

Cloud masking tool

The NoData value is applied to pixels identified by the cloud mask.
It is also possible to apply a buffer to cloud pixels which can be useful to dilate masked area in case the mask doesn’t cover the thinner border of clouds.
This tool is very useful in conjunction with the new tool Mosaic band sets that allows for the mosaic of the corresponding bands of two or more band sets. An output band is created for every corresponding set of bands in the band sets.
The NoData values of one band are replaced by the values of the corresponding band of the next band set. This can be very useful for creating a cloud free mosaic after cloud masking.

Mosaic band sets tool
I have updated the SCP dock in order to be more productive and user friendly. The tab Home includes the buttons for opening the SCP functions, with a section News where updates and news about SCP and related services will be shown on startup.
Other tabs include the Training input commands and the Classification commands.
In addition, several buttons are always visibile in the left part of the dock, easing the launch of other SCP tools.
SCP dock
The training input allows for the creation of the training input file (.scp ) which is required for storing ROIs and spectral signatures for image classification. The loaded training input is always visible in the top of the dock.
I've tried to maximize the space for the ROI Signature list.
A new option allows you to automatically save the ROI Signature list to the training input file every time a ROI is saved (with the current version of SCP, the ROI Signature list is saved only when the QGIS project is saved).
In the same fashion, classification commands are placed in a new tab.
I have changed the threshold behavior: if the threshold value is greater than 0 , this value is used for all the spectral signatures; otherwise, thresholds for each signatures can be defined in the tab Signature threshold. This new SCP dock should be more usable also with small screen devices.

Following the complete changelog:
    -version updated for QGIS 3
    -updated the Main interface with new tabs and design
    -in tab Band set added option for multiple band set definition that can be moved and closed
    -in tab Band set quick wavelength set according to band number of sensor
    -new tab Download products for searching and downloading free images and products
    -in tab Download products added download and preprocessing of Sentinel-2 Level 2A
    -in tab Download products added download of Sentinel-3 OLCI
    -in tab Download products added image preview with click on Product list items
    -in tab Download products added option to import and export table of product download
    -in tab Download products the Product list is saved with the project
    -in tabs Landsat Sentinel-2 and ASTER added option to limit DOS1 correction only to blue and green bands
    -in tab Preprocessing added tool for Sentinel-3 OLCI
    -in tab Preprocessing added tool Mosaic band sets for the creation of multiband mosaics
    -in tab Preprocessing added tool Cloud masking of a band set which is based on the values of a classification
    -in tab Band processing added tool Clustering with K-means and ISODATA algorithms
    -in tab Band processing added tool Spectral distance for calculating pixel distance between two band sets
    -in tab Band processing added tool Band combination for calculating a raster of band combinations from a band set
    -in tab Postprocessing added tool Class signature for calculating the spectral signatures of classes in a classification using a band set
    -in tab ROI Creation added option to autosave training input (backup file created when saving QGIS project)
    -in tab Clip Multiple Rasters added option to select a vector field for iterating through each vector polygon and add field value to the output name
    -in Working toolbar added possibility to plot spectral signatures of the same pixel for all the band sets (pressing the button ROI region growing then CTRL + mouse right click in the map)
    -in tab Classification the threshold value if > 0 is used for all the spectral signatures;
    -in tab Edit raster added vector as variable name for using vector value in expression
    -in tab Batch added several new functions and changed some of the function variable names
    -in tab Batch added label for checking the expression
    -in tab Batch added table containing the list of functions
    -in tab Settings Processing added SMTP process notification
    -in tab Settings Debug added table of Log
    -in tab Multiple ROI creation now can import a point shapefile for point coordinates
    -in tab Multiple ROI creation the random point creation avoids raster NoData
    -in Spectral Signature Plot fixed signature plot for large values
    -various bugfixing and improvements

For any comment or question, join the Facebook group and the Google+ Community about the Semi-Automatic Classification Plugin.

Newer posts Older posts