Manually collecting fiducial marks

OrthoEngine links the fiducial-mark coordinates entered from the camera-calibration report to the positions that you identify on the scanned image. You must identify the fiducial marks in each image. Images from digital cameras do not contain fiducial marks.

Tip: If you are working in a project with a large volume of images, start with a limited number of images (up to five), complete the calculation of the math model, and then check for errors before continuing. It is easier to locate bad points on a few images than in the entire project.

To manually collect fiducial marks

Open an uncorrected image.
In the image, click the approximate location of a fiducial mark.
On the Zoom toolbar, click Zoom In until you can see the fiducial mark clearly.
Click precisely in the center of the fiducial mark.
In the Fiducial Mark Collection window, beside the fiducial-mark location corresponding to the mark that you clicked in the previous step, click Set.
Disregard the orientation of the scanned image. Follow the locations of the fiducial marks as they appear in the image on-screen. For example, if you clicked in the upper-left corner of the image to collect the fiducial mark, beside Top left in the Fiducial Mark Collection window, click Set. OrthoEngine automatically adjusts its parameters to account for the orientation of the scanned image relative to the orientation of the camera.
On the Zoom toolbar, click Zoom Out to reduce the magnification, and then to collect the remaining fiducial marks in the image, repeat the previous two steps.
In the Fiducial Mark Collection window, under Errors, click Clear beside any fiducial marks where the error is not acceptable, and then repeat the collection process.
OrthoEngine compares the computed fiducial-mark positions based on the on-screen measurements with the fiducial information you entered from the camera-calibration report.

Error should be less than one pixel, unless the image is scanned at very-high resolution. Large errors may indicate that either the coordinates from the camera-calibration report were entered incorrectly or the fiducial mark was collected incorrectly from the scanned image.
In the Calibration edge list, select the position of the data strip as it appears in the image on the screen.
Because the camera calibration is based typically on the data strip being oriented on the left, OrthoEngine compensates for the difference automatically. If your scanned image does not include the data strip, orient the original diapositive or print to match the on-screen image, and then deduce where on-screen the data strip should be.
When you are satisfied with the results, click OK.

After you identify the fiducial marks in your scanned image, the parameters from the camera-calibration report are used during the calculation of the math model and product generation to compensate for the distortions introduced by the camera.