About regions

Regions are areas on an echogram that you can define manually with a selection tool, with an algorithm (e.g., School Detection module algorithms) or import. Once you have defined a region, Echoview makes it available to other echograms in the EV file.

Echoview supports:

• 2D regions for single, split and dual-beam echograms and cruisetracks or alongtraks (see Using cruise tracks), and
• 3D regions for multibeam echograms and scenes.

Refer to About region dimension.

Inspect regions in Echoview using the

• Regions window
• Region browser dialog box
• (3D Object) Properties dialog box

Creating and editing a region

Refer to the Defining and creating regions and Editing regions pages.

Region properties

Property	Description
ID	The index of a region in the order it is created. The ID is fixed by Echoview. You can see it in the Regions window and in Region exports.
Name	A descriptor of your choice. You can name a region using the Regions window or the Region browser dialog box.
Type	Refer to About region type.
Class	Refer to About region class.

Displaying regions

Echoview draws regions on echograms. The colors of a region indicate its type (see the About analysis domains page for an example). You can modify the default colors with a .evc file.

Toggle which region classes (see About region class) are visible on an echogram from the Regions page of the Variable properties dialog box.

Scenes display 3D regions as 3D objects.

Region colors

The default region type border and fill colors can vary with color scheme. Use the Echogram Display section on the Classes page of the EV File Properties dialog box to specify custom region type border, fill and shading properties.

A series of eight default colors and hatching is used for fish track regions.

3D regions on multibeam echograms are a colored border and cross hatching across pings.

Working with regions

Active region

An Active region is the region available for analysis, export and synchronizing. You can only have one Active region at a time. To make a region Active:

1. On an echogram, use the rectangle tool and click on a region.

- OR -

2. On the Regions window, double-click a region

- OR -

3. In the Region Browser dialog box, scroll through the regions using the next and previous arrows.

When a region is the Active region, you can

• Export the Sv value
• Graph the frequency distribution
• Integrate the region
• Delete the region
• View a synchronized display of the region
• Change the region class with a Region Class keyboard shortcut

The Active region on an echogram has a border 1 pixel wider than other regions, and a fill color (dependent on the type of region).

The Active region is displayed in bold text on the Regions window.

Selected regions

You can have one or more Selected regions. To select regions, open the Regions window and:

1. Click on a single region.

- OR -

2. Hold down the SHIFT key and select multiple regions.

- OR -

3. On the Shortcut menu, select Select All.

When you have one or more regions Selected, you can use the Region Editor dialog box to:

• Change region type
• Change region class
• Shift region in time
• Shift region in depth
• Classify regions using the Rules that apply conditional tests and assign specified region classes. For more information refer to Classifying regions
• Delete regions

Operators

• Region bitmap
• Region statistic

Notes:

• The Notes page of a region can be used to record additional information about a region. If the region has been created by a 2D school detection or 3D school detection, the School detection settings are recorded on the Detection Settings page.
• Be aware that changes to calibration settings that are used in range calculations, may shift ping data in the depth dimension but will not automatically adjust the position of existing regions and lines. You should review any existing regions and lines to ensure they are still valid. For more information refer to Range calculation effects on regions and lines.
• Complex acoustic variables may differ in time or depth from acoustic variables and this will consequently affect the display of regions in echograms.

See also

About 3D regions
Classifying regions
Region graphs
Exporting regions
Joining regions
Editing 2D regions