This tab allows for the automatic creation of ROIs, useful for the rapid classification of multi-temporal images, or for accuracy assessment. Given a list of point coordinates and ROI options, this tool performs the region growing of ROIs. Created ROIs are automatically saved to the :ref:`training_input`. The :guilabel:`active band set` in :ref:`band_set_tab` is used for calculations.
| Tool symbol and name | Description |
|---|---|
:guilabel:`Number of points`  |
set a number of points that will be created when
:guilabel:`Create points`  is clicked |
 :guilabel:`inside grid` |
if checked, the :guilabel:`band set` area is divided in cells where the
size thereof is defined in the combobox (image unit, usually meters);
points defined in Number of random points are created randomly
within each cell |
| :guilabel:`min distance` |
if checked, random points have a minimum distance defined in the combobox (image unit, usually meters); setting a minimum distance can result in fewer points than the number defined in :guilabel:`Number of points` |
| :guilabel:`Create points` |
create random points inside the :guilabel:`band set` area |
:guilabel:`stratified for the values`  |
if checked, create random points inside the values defined in the
expression calculated for the first band of the defined band set; the
expression must include the variable raster ; multiple expressions
can be entered separated by semicolon ( ; ) but the total number of
stratified points is the same as the
defined :guilabel:`Number of points` |
| :guilabel:`of the first band of band set` |
defines the :guilabel:`band set` in
:guilabel:`stratified for the values` |
The table :guilabel:`Point coordinates and ROI definition` contains the following fields.
| X | Y | MC ID | MC Name | C ID | C Name | Min | Max | Dist | Rapid ROI band |
|---|---|---|---|---|---|---|---|---|---|
| point X coordinate (float) | point Y coordinate (float) | ROI Macroclass ID (int) | ROI Macroclass Name (text) | ROI Class ID (int) | ROI Class Name (text) | the minimum area of a ROI (in pixel unit) | the maximum width of a ROI (in pixel unit) | the interval which defines the maximum spectral distance between the seed pixel and the surrounding pixels (in radiometry unit) | if a band number is defined, ROI is created only using the selected band, similarly to :guilabel:`Rapid ROI band` in :ref:`ROI_list` |
The following tools are available.
| Tool symbol and name | Description |
|---|---|
 |
add a new row to the table; all the table fields must be filled for the ROI creation |
 |
delete the highlighted rows from the table |
 |
import a point list from text file or a point shapefile to the table;
in case of text file, every line must contain values separated by
tabs of X, Y, MC ID, MC Name, Class ID, C Name,
Min, Max, Dist, and optionally the Rapid ROI band;
in case of shapefile, only point coordinates are imported |
 |
export the point list to text file |
| :guilabel:`Calculate sig.` |
if checked, the spectral signature is calculated while the ROI is saved to :ref:`training_input` |
:guilabel:`RUN`  |
start the ROI creation process for all the points and save ROIs to the :ref:`training_input` |