The SPEAR Image-to-Map Registration tool provides a simplified way to warp an input image to match the map information of a base image, while retaining the original spatial resolution. This tool can be used to warp images to match a Controlled Image Base (CIB), a database of orthophotos providing a consistent baseline for map information. By tieing all images to the CIB, extracted features can be visualized in GIS systems and compared to imagery of the same area collected at different times. In areas with significant terrain, consider using the SPEAR Orthorectification tool and setting ground control points for better results.

  1. From the Toolbox, select SPEAR > SPEAR Image-to-Map Registration. The SPEAR Image-to-Map Registration Wizard displays the File Selection panel.
  2. You will select two images: one will be used as the base image and the other will be warped to match that image. Click Select Base Image, choose a file for the base image, then click OK.
  3. Click Select Image to Warp, choose a file for the warp image, then click OK. The Band Matching Choice dialog appears.
  4. Select the band to use for auto tie point matching, then click OK. Select the band that most closely mimics the base image. In most cases, the visible red band is appropriate.
  5. To optionally process only a portion of the scene, click Select Subset. A Select Spatial Subset dialog appears. Subsetting is applied to both images. When finished, click OK to return to the File Selection panel.
  6. By default, output files are saved to the same directory and use the same rootname as the input file, minus any extension. The filename is appended with _imagetomap. To change the directory and/or filename, click Select Output File.
  7. Click Next. The Method Selection dialog appears with coregistration parameters. Click Next. The next two dialogs: the Review Tie Points dialog and the Check Coregistration dialog allow you to check the accuracy of the coregistration and to fix tie points if needed. When complete, click Next on each dialog.
  8. Processing is complete, click Finish to exit the Wizard.