Geometrically correcting images

Before you process your images, you must make sure that the Output Pixel Spacing on the Set Projection window is set correctly. The Output pixel spacing determines the size of the corrected images.

  1. If you are correcting images as part of a project to mosaic raw (unreferenced) images, the master image will be identified by 'No Model'. Under Available images, click the master image and select Use raw image as master. The master image is now labeled 'Master'.
  2. Under Available images, select the images that you want to correct and click the arrow button to move the images under Images to process. The images are processed in the order that they appear under Images to process. If you have already corrected the image, Delete existing file appears next to the image. When the image is processed, the previous version is replaced. If you have not corrected the image previously, Create new file appears.
  3. Under Images to process, select an image.
  4. In Input channels, click All to select all the image channels or click Channels and type the channels that you want in the Channel box. You can use a dash between the channel numbers to indicate a range and a comma between individual channel numbers.
  5. Repeat the step for the remaining images or select Apply input channel selection to all files to use the same channel selection for the remaining images.
  6. You can delete the uncorrected image from the disk when the process is complete. Select an image under Images to process, and select Delete input file when done. Repeat for each image that you want to delete after the image is processed.
  7. Under Corrected Image in the File box, you can type a new file name for the corrected image or click Browse to select the file. The default file name is "o" followed by the raw image's file name. If you replace the default file name with the file name of an existing file with matching georeferencing and resolution, the newly corrected image will replace the old. If the georeferencing and resolution of the existing file do not match the newly corrected image, you will have to type a new file name.
  8. The Upper left and Lower right values may be default values or the extents from an existing orthorectified image. You can click Recompute to reset Upper left and Lower right to the default values.
  9. In Working cache, type the maximum amount of RAM that you allocate for this process. The limit should not involve more than half the RAM. Specifying more than half may significantly reduce performance.
  10. In Sampling interval, type the interval between the pixels used to process the image.
  11. In the Resampling list, click the processing method of your choice.
  12. Depending on the Resampling option that you chose, one of the following may become available.
    • In Filter Size , type the number of pixels in width in the X box and the number of pixels in length in the Y box to determine the size of the kernel used with the filter.
    • In Gaussian SQ box, type the first value and in the 2 box type the second value to determine the size of the kernel for the Gaussian Filter.
    • Click Browse to select the Kernel file.
  13. Under Processing Start Time, click Start now or Start at (hh:mm) and set the time when you want the operation to begin (within the next 24 hours).
  14. Click Correct Images. A progress monitor displays the status of the images being processed. Click Cancel if you want to stop the process.
Parent topic: Correcting images with a simple math model
Previous topic: Opening the Geometric Corrected Image Production window

© PCI Geomatics Enterprises, Inc.®, 2026. All rights reserved.