The :guilabel:`SCP dock` allows for the the creation of ROIs (Regions Of Interest) and spectral signatures required for the classification of a :ref:`band_set_tab`. The :ref:`training_input`, created with :guilabel:`SCP`, stores the ROI polygons and spectral signatures; depending on the algorithm, the training could be performed using ROI polygons (e.g. :ref:`random_forest_definition`) or spectral signatures (e.g. :ref:`spectra_angle_mapping_algorithm`).
ROIs are polygons used for the definition of the spectral characteristics of land cover classes. Spectral signatures of classes are calculated from the ROIs or can be imported from other sources (see :ref:`import_signatures_tab`). It is worth pointing out that classification is always based on spectral signatures.
:guilabel:`SCP` allows for the creation of :guilabel:`temporary ROI polygons` using a region growing algorithm or drawn manually with the tools provided in the :ref:`working_toolbar`. These are :guilabel:`temporary ROI polygons` because the ROI creation is an interactive process, and one can refine the geometry according to photointerpreation. Then, one can save :guilabel:`temporary ROI polygons` in the :ref:`training_input` which is the actual input for classifications.
The :ref:`training_input` is composed of a vector part that stores the geometries and a spectral signature part, which are managed by :guilabel:`SCP`. A temporary layer is added to QGIS but the actual file is saved and modified during the editing in :guilabel:`SCP`.
In :guilabel:`SCP`, land cover classes (and ROIs) are defined with a system of :guilabel:`Classes` (:guilabel:`Class ID`) and :guilabel:`Macroclasses` (:guilabel:`Macroclass ID`) (see :ref:`classes_definition`) that are used for the classification process; each :guilabel:`Macroclass ID` is related to a :guilabel:`Macroclass Information` (e.g. macroclass name) and each :guilabel:`Class ID` is related to a :guilabel:`Class Information` (e.g. class name), but only :guilabel:`Macroclass ID` and :guilabel:`Class ID` are used for the classification process.
The use of the :guilabel:`Macroclass ID` or :guilabel:`Class ID` for classifications is defined with the option :guilabel:`Use MC ID or C ID` in the :ref:`classification_alg`. Using :guilabel:`Macroclass ID` instead of :guilabel:`Class ID` is useful to group materials that belong to the same land cover class but have spectral signatures that are distant enough to be considered as different materials (e.g., different types of vegetation).
The classification can be performed for the entire image (see :ref:`classification_alg`) or for a part of it creating a :ref:`classification_preview`.
The :guilabel:`SCP dock` contains the following tabs:
The left side of :guilabel:`SCP dock` contains buttons for accessing the main functions of :guilabel:`SCP`.
The tab :guilabel:`Home` contains the buttons for accessing the main functions of :guilabel:`SCP`:
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:ref:`band_set_tab` |
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:ref:`tools_tab` |
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:ref:`download_tab` |
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:ref:`pre_processing_tab` |
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:ref:`band_processing_tab` |
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:ref:`post_processing_tab` |
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:ref:`band_calc_tab` |
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:ref:`script_tab` |
This section displays news about the :guilabel:`SCP` and related services. News are downloaded on startup (internet connection required). It can be enabled or disabled in the settings :ref:`settings_tab`.
This tool allows for the creation of the training input file (.scpx )
required for storing ROIs and spectral signatures.
The training input file is created according to the characteristics of the
:guilabel:`active band set` defined in :ref:`band_set_tab`.
A new training input file should be created for every :guilabel:`band set`,
unless the :guilabel:`band sets` have the same spectral characteristics and
coordinate reference system.
| Tool symbol and name | Description |
|---|---|
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open a training input file; ROIs and spectral signatures are loaded in :ref:`ROI_list`; the vector part of the training input is loaded in QGIS |
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create an empty training input file (.scpx); the vector part of the
training input is loaded in QGIS; also a backup file is created (a
file .scpx.backup in the same directory as the file .scpx) when
the QGIS project is saved; to use the backup file simply rename it
deleting the ending .backup extension and open it as training input |
:guilabel:`Training input`   |
it displays the path to the training input file |
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remove the training input |
The training input is displayed in QGIS as vector file. ROIs and spectral signatures are displayed in the :ref:`ROI_list`.
Warning
In order to avoid data loss, do not edit the vector :guilabel:`Training input` using the QGIS tools. Use only the tools of :guilabel:`SCP` for managing the :guilabel:`Training input`.
The tab :guilabel:`ROI & Signature list` displays the ROI polygons and spectral signatures contained in the training input file. The tab :guilabel:`ROI & Signature list` is structured as tree list, where every ROI is grouped in the corresponding Macroclass.
A filter for names can be defined in :guilabel:`Filter` .
The tree list :guilabel:`ROI & Signature list` has the following fields:
- :guilabel:`MC ID`: Macroclass ID is the root of corresponding ROIs and signatures; it can be edited with a single click; if the ID of a spectral signature is set 0, then pixels belonging to this signature are labelled as unclassified; every listed ROIs or signatures has a selection checkbox (only the spectral signatures checked in this list are used for the classification process);
- :guilabel:`C ID`: Class ID; it can be edited with a single click;
- :guilabel:`Name`: Macroclass and Class Name; it can be edited with a single click;
- :guilabel:`Type`: type of the item:
- :guilabel:`R` = only ROI polygon;
- :guilabel:`S` = only spectral signature;
- :guilabel:`R&S` = both ROI and spectral signature;
- :guilabel:`Color`: C ID color; double click to select a color for the class that is used in the classification; if the ID of a spectral signature is set 0, then pixels belonging to this signature are labelled as unclassified;
Changes in the :guilabel:`ROI & Signature list` are applied to the
file :ref:`training_input` only when the QGIS project is saved
(but there is also the option 
:guilabel:`Autosave`).
ROIs can be edited, deleted and merged from this list.
Tip
According to :ref:`classification_alg`, classifications performed using :guilabel:`C ID` have the colors defined for classes in the :ref:`ROI_list`; classifications performed using :guilabel:`MC ID` have the colors defined for the macroclasses.
If an item is a ROI polygon, double click the item to zoom to that ROI in the map. Items in the list can be highlighted with the mouse left click.
Tip
ROIs and spectral signatures can be imported from other sources (see :ref:`import_signatures_tab`) and exported (see :ref:`export_signatures_tab`).
The following tools are available.
| Tool symbol and name | Description |
|---|---|
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merge highlighted spectral signatures or ROIs obtaining a new signature calculated as the average of signature values for each band (covariance matrix is excluded) |
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calculate spectral signatures of highlighted ROIs using the :guilabel:`active band set` in :ref:`band_set_tab` |
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delete highlighted ROIs and signatures |
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show the ROI spectral signature in the :ref:`spectral_signature_plot`; spectral signature is calculated from the :ref:`band_set_tab` |
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add highlighted ROIs to the :ref:`scatter_plot` |
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open the tab :ref:`import_signatures_tab` |
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open the tab :ref:`export_signatures_tab` and export highlighted items |
:guilabel:`ROI & Signature list` is complementary to the :ref:`working_toolbar` and it allows for saving ROIs to the :ref:`training_input` defining classes and macroclasses. A :ref:`band_set_tab` must be defined before the ROI creation, and ROI polygons must be inside the area of the :guilabel:`Band set`.
| Tool symbol and name | Description |
|---|---|
:guilabel:`MC ID`  |
ROI Macroclass ID |
| :guilabel:`MC Name` |
ROI Macroclass Name |
| :guilabel:`C ID` |
ROI Class ID |
| :guilabel:`C Name` |
ROI Class Name |
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undo of ROI creation from the :ref:`training_input`; it is possible to undo a maximum of 10 actions |
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redo ROI creation in the :ref:`training_input` |
| :guilabel:`Autosave` |
if checked, automatically save the :guilabel:`ROI & Signature list` to the :ref:`training_input` every time a ROI is saved |
| :guilabel:`Signature` |
if checked, while saving a ROI, the spectral signature thereof is calculated (from :ref:`band_set_tab` pixels under ROI polygon) and saved to :ref:`training_input` (calculation time depends on the band number of the :guilabel:`active band set` in :ref:`band_set_tab`) |
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save the temporary ROI to the :ref:`training_input` using the defined classes and macroclasses; ROI is displayed in the :ref:`ROI_list` |
A right click on :ref:`ROI_list` allows for opening a menu containing several functions to manage ROIs and spectral signatures.
| Tool symbol and name | Description |
|---|---|
 :guilabel:`Zoom to` |
zoom to highlighted items (if ROI polygons) in the map |
 :guilabel:`Check/uncheck` |
check or uncheck highlighted items |
 :guilabel:`Clear selection` |
clear selection of highlighted items |
 :guilabel:`Collapse/expand all` |
collapse or expand all macroclasses |
 :guilabel:`Change MC ID` |
edit the macroclass of highlighted items (using the
value :guilabel:`MC ID` displayed in :ref:`ROI_list`);
if a macroclass is selected, the function is performed to all the
included items |
| :guilabel:`Change color` |
select a color for the highlighted items; if a macroclass is selected, the function is performed to all the included items |
| :guilabel:`Merge items` |
merge highlighted spectral signatures or ROIs obtaining a new signature calculated as the average of signature values for each band (covariance matrix is excluded); if a macroclass is selected, the function is performed to all the included items |
| :guilabel:`Calculate signatures` |
calculate spectral signatures of highlighted ROIs using the :guilabel:`active band set` in :ref:`band_set_tab`; if a macroclass is selected, the function is performed to all the included items |
| :guilabel:`Delete items` |
delete highlighted ROIs and signatures; if a macroclass is selected, the function is performed to all the included items; |
| :guilabel:`Add to spectral plot` |
show the ROI spectral signature in the :ref:`spectral_signature_plot`; spectral signature is calculated from the :ref:`band_set_tab`; if a macroclass is selected, the function is performed to all the included items |
| :guilabel:`Add to scatter plot` |
add highlighted ROIs to the :ref:`scatter_plot`; if a macroclass is selected, the function is performed to all the included items |
 :guilabel:`Properties` |
show the properties of highlighted items; |
| :guilabel:`Import` |
open the tab :ref:`import_signatures_tab` |
| :guilabel:`Export` |
open the tab :ref:`export_signatures_tab` and export highlighted items |
:guilabel:`ROI options` are useful for displaying pixel values or improving the creation of ROIs.
| Tool symbol and name | Description |
|---|---|
:guilabel:`Display`  |
if the ROI creation pointer is active (see :ref:`working_toolbar`), the pixel value of selected vegetation index is displayed on the map; vegetation indices available in the combo box are: * NDVI (Normalized Difference Vegetation Index); NDVI requires the near-infrared and red bands; * EVI (Enhanced Vegetation Index); EVI requires the blue, near-infrared and red bands converted to reflectance; wavelengths must be defined in the :ref:`band_set_tab`; * Custom; use the custom expression defined in the following line |
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set a custom expression; expression is based on the :guilabel:`Band set` and bands such as band 1 is referred to as "b1", band 2 as "b2" and so on; also reference to band names such as "#NIR#" or "#RED#" can be used |
| :guilabel:`Rapid ROI b.` |
if checked, temporary ROI is created with region growing using only one :ref:`band_set_tab` band (i.e.region growing is rapider); the band is defined by the :guilabel:`Band set` number; if unchecked, ROI is the result of the intersection between ROIs calculated on every band (i.e. region growing is slower, but ROI is spectrally homogeneous in every band) |
| :guilabel:`Auto-plot` |
calculate automatically the temporary ROI spectral signature and
display it in the :ref:`spectral_signature_plot` (MC Name of this
spectral signature is set tempo_ROI) |
| :guilabel:`Auto-refresh ROI` |
calculate automatically a new temporary ROI while :guilabel:`Region growing parameters` in the :ref:`working_toolbar` are being changed |
| :guilabel:`Maximum training buffer` |
defines the maximum number of action for undo and redo ROIs; the higher is the number, the more is the required memory |