Creating a project to adjust orthos for mosaicking

It is common for orthorectified images used in a mosaic to be misaligned due to inaccurate ground control points (GCP) or a low-accuracy digital elevation model (DEM) associated with the images. In such cases, you can use the Adjust Orthos option to fix misalignments and improve the accuracy of the mosaicking results. Adjust Orthos uses the Thin Plate Spline math model to correct the overlap area in one of the ortho images so that it aligns more precisely with the other ortho image.

To create a project to adjust orthos for mosaicking

  1. On the File menu, click New.
  2. In the Project Information window, type a file name for your project in the Filename box.

    This will be the file name of your project after you click OK.

  3. In the Name box, type a name for the project.

    The name you enter will appear on the title bar of the OrthoEngine window

  4. In the Description box, type a brief description of the project.

    A good description helps you—and most importantly, others—to identify the subject and contents of the project.

  5. Under Math Modeling Method, click Adjust Orthos.
Tip: After you set up your project to adjust the ortho images for mosaicking, do the following:
  1. Collect GCPs.

    If you collect the GCPs manually, all of the points must be at ground level. The more GCPs you collect, the more accurate will be the correction result. If you instead use automatic GCP collection, manually remove any mismatched points and points that are not at ground level, such as points on the tops of roofs or buildings.

  2. Geometrically correct the images.

    Draw a binding polygon that includes all of the GCPs collected. Any area outside the bounding rectangle will not be modified.

  3. Generate a new ortho image.
Parent topic: Creating a project and selecting a math model
Previous topic: Creating a project using the Thin Plate Spline math model
Next topic: Mosaicking imagery

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