Learn what chromatic aberration is and how to correct it in WingtraHub for the oblique Sony a6100 images.
What is Chromatic Aberration?
Chromatic aberration is a commonly observed effect, especially in wide-angle lenses. It is caused by lens dispersion which results in colors being focused at slightly different positions in the focal plane or having different focal planes for each color.
In the image below from top to bottom, we first see a light that is perfectly aligned on the focal plane, then longitudinal chromatic aberration where the focal plane is at a different distance from the lens depending on the wavelength, and finally transverse chromatic aberration where different wavelengths are focused in different points in the focal plane.
How does it affect the image quality of Oblique Sony a6100 imagery?
Chromatic aberration is also known as “color fringing” or “purple fringing” and it is an effect that causes edges located at the edges of images to have visible purple and green fringes. These should not impact the accuracy of the orthomosaic or the 3D model, however, they are still visible and affect the appearance of the results.
How can chromatic aberration be corrected?
To some extent, transverse chromatic aberration can be corrected in WingtraHub by shifting the color channels to match up again. A mathematical model for chromatic aberration, calibrated to our lens, is implemented to perform this correction. This results in noticeably more visually appealing results and it does not negatively impact the accuracy. Note, however, that it cannot completely eliminate the effects of chromatic aberration.
The option to enable this correction can be found in: Settings->General->Geotagging->Enable chromatic aberration correction. Enabling this option will apply the correction to all the images that will be stored in the Output folder after the geotagging process is completed. Note that the Output geotagged images option should be selected to get the corrected images. Read more information about the PPK geotagging process in the article PPK geotagging.
The option to enable the chromatic aberration correction is disabled by default, as it is a computationally intensive task with a large impact on processing time.