Calibration Registration instance

There are two registration methods for fixed-point Video Registration. The first one is to import Reference map for control point selection registration, and the second one is to input Camera Parameter Registration. Let's take the fixed-point rotation video as an example to introduce the whole process of Calibration Registration.

Import Reference map registration

Step 1: Access Video

Note: The Advance Settings button reopens the Add Video Data dialog. See the Create a new Video Dataset for other Video Dataset access methods.

Right-click Datasource and select the Create Dataset option to bring up the Create Dataset dialog, select Video from the Type to bring up the Add Video Data dialog, and click the Add Local Video button in the dialog. Select the video file you want to import.
The Add Video Data dialog disappears, and the imported video file is named according to the Dataset Name in the Create Dataset dialog. You can customize the video Dataset Name.
The coordinate system can be set in the Create Dataset dialog box. Here, we require the Coordinate System Settings to be the Projected Coordinate System. Generally, the Mercator projection is selected.
After setting, click the OK button in the Create Dataset dialog box to complete the video access.

Step 2: Obtain the registration Reference map

The Reference map must select data that is consistent with the Video Dataset coordinate system.

Use Online Map in WebData source, click Skymap in Start tab-> Datasource group-> WebDrop-down Button, and select Skymap in the pop-up Open WebData source dialog box. Select Global Image Map Service (Mercator) for the service name, and click the OK button to display Map Datasource in Workspace Manager. Transfer the imgDatasource under the Datasource to the Map, Search And Locate to the location of the video shooting location, and then Save Map.
Use the own Image Data. If there is Image Data near the video shooting location, it can also be used directly. Image DatasetAdd to Map the window and then save it as a map. In this example, we use the own Image Data as the Reference map.

Step 3: Create a new Video Registration window

Open the Video Dataset to the Video Map window, Select Video Map tab-> Video Registration group-> Registration Mode (or Video Registration tab-> Display Mode group-> Registration Mode button to pop up the Reference map dialog.
Click the Add button in the dialog box, and select the map saved in the previous step as the Reference map of Video Registration in the pop-up selection dialog box.
Click the OK button on the Select dialog and the Reference map dialog to complete the Video Registration window.
Since the direction of the opened map data is inconsistent with that of the video data, it is not easy to mark the control point. Here, the Rotation angle is set to 260 °, and the Reference map can basically match the video data.

Step 4: Mark Control Points

Because the video is a rotating video, there are different angles, we can choose the required angle to spatialize, and we can also spatialize multiple angles separately.

Single-angle spatialization: Here we first mark the direction of horizontal angle 234 ° and vertical angle 37 °.
- Play Video or to the angle, right-click the video layer in the Layer Manager, and select Properties to open the Video Layer Properties panel. Click the Add button on the toolbar above the Video Parameters module to add a piece of Video Parameters for this moment; then delete the 0-second Video Parameters added by default when creating a new Video Dataset.
- Click Video Registration tab-& gt Calibration Registration group-& gt Click Prick Point to calibrate the corresponding control points in Registration Map and Reference Map, as shown in the figure below:
- marked points should be evenly distributed in the whole video screen as far as possible. The more points, the better. If the elevation value of each point is known, the elevation value can also be input, which can improve the accuracy of the puncture point.

Multi-angle spatialization: When the video is rotated to other angles with poor registration accuracy, multi-angle registration can be performed, and the multi-angle registration process is consistent with the single-angle process.
- Open the Video Layer Properties panel, add Video Parameters at the angle with poor accuracy, and mark
  the control points separately.
- Then input the PTZ value of each angle at PTZ position, which can be obtained from the lower right corner of the video; it is not necessary to input the PTZ position when spatializing a single angle.
- Finally, input the approximate range of the known camera position and height, and then Perform registration.

Step 5: Input known camera parameters

If a part of Camera Parameters is known, the known parameters can be input to perform fitting registration with the selected control points before Perform registration to improve the registration accuracy. For example, in this example video, the longitude, latitude and altitude range of the location of the camera are known:

Click the Video Registration tab-> Calibration Registration group-> Registration Parameters button to bring up the Registration Parameters dialog. In the dialog box, enter the value of XY and the maximum and minimum values of Z;
Then set Iterations and sample size. The larger the value, the higher the accuracy. However, when the value reaches a certain value, the effect will not be obvious no matter how large the value is. The default values of 1000 and 200 can meet most situations. In this example, the default values are retained here;
Height involved in computation: if the elevation value of each point is known, this item can be checked. This example is not checked here.

Step 6: Perform registration

Perform registration after inputting Camera Parameters. Click the Video Registration tab-> Calibration Registration group-> Perform Registration button to perform registration by rotating one angle of the video.

Step 7: View Registration Results

After the registration is completed, the total error and the average error of each point can be viewed in the Output Window. Then switch to Browse Mode to overlay with Vector Data for a more intuitive view of the registration results.

Step 8: Optimize Registration Accuracy

If the registration effect is not ideal, it can be optimized. After Perform registration, two Point Datasets will be generated at the same angle or moment of the video. If multiple angles or moments are marked, two Point Datasets will be generated at each angle or moment. That is, SourceDataset and ResultDataset, SourceDataset is the marked control point, and ResultDataset is the point after the marked control point is mapped to Model Convert through the registered video geographic space.

The two Point Datasets at the same angle or moment generated after the registration of the execution completed can be added to the same map, so that the control points can be seen more intuitively, and if the control points are too far away, it indicates that there is a problem with the marking of the control points. You can also browse the ResultDataset Properties table and check the Error field to see which pair of control points has the largest error, and then repeat the previous steps to enter the Registration Mode, modify the control points, and then Perform registration.

Via Camera Parameter Registration

If all Camera Parameters are known, Video Registration can also be done by manually entering the Camera Parameters.

Step 1: Access Video

The access Video Operation is consistent with the access video in Import Reference map registration.

Step 2: Set camera parameters

Click the Set camera parameters button on the Video Layer Properties panel according to the user's photographing position information. Manually enter Camera Intrinsic Parameters, Extrinsic Parameter information for the angle. Refer to Description of Camera Parameters for details of Camera Parameters.

For multi-angle registration, you need to select Video Parameters of different angles in the Video Parameters list, and then input Camera Parameters of each angle.

Step 3: Save Camera Parameters

Click the Video Registration tab-> Camera Parameter Registration group-> Save Parameters button to save the Video Parameters to the Video Dataset. The operation of calibrating the Video Registration is completed.

Import Reference map registration

Via Camera Parameter Registration

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