Calculate Error

Function Description

Calculate Error will calculate the error information between the registration control point and the reference control point according to the selected configuration algorithm. The smaller the error is, the better the registration effect is, and vice versa. Registration Info can be used to determine whether to modify the selection of control points to achieve better configuration results.

The units of error and the units of Current DataPlanar Coordinate System are the same. Usually, the accuracy of registration is less than 0.5 pixels. If the resolution of the image is 30 meters, the total RMSE is required to be less than 15 meters.

In terms of the requirements of registration accuracy, the requirements of each project are different. When the RMSE of some control points is greater than acceptable total RMSE, the control points can be deleted or re-edited to reduce the overall RMSE and improve the registration accuracy.

Function entrance

  • Registration tab-> Operation group-> Calculate Error button;

Operation steps

  1. Select a registration algorithm in the Registration tab-> Operation group, which provides four commonly used algorithms: linear registration, quadratic polynomial registration, rectangular registration and offset registration. You can select the appropriate algorithm according to your actual needs. Different algorithms have different requirements for the number of registration control points. Refer to the Introduction to Registration Algorithm for the registration algorithm.
  2. In the Calculate group of the Registration tab, click the Calculate Error button to calculate the error, and the error of each control point is listed in the control point list. These errors include the X residual, the Y residual, and the RMSE, and the total RMSE value is output on the status bar in the Registration Window. Please refer to Introduction to Registration Errors for the specific meaning of registration error.
Hint :
    Click the right mouse button anywhere in the
  • control point list, and select the Export Registration Info command in the pop-up Context Menu. Save the Registration Info for all control points as Registration File (*.druf). For the next use, you only need to import the saved Registration File. For Export Registration File, see : Import and Export Registration Info films.

Related topics

Step 1: Create New Registration

Step 2: Add control point

Step 4: Perform registration

Import and Export Registration Info films