An Essential Batch Image Processing Tool For Accurately Aligning Multi-camera Images
AeroAlign is a simple yet powerful batch image processing tool for aerial images acquired from small and medium format cameras. It has two main functions:
- To remove lens distortion from images
- To align images from multiple cameras to create multi-band images
Importantly, it can process a single image pair, or batch process thousands of images autonomously.
Lens Distortion Removal
Lens distortion exists in all cameras and lenses, irrespective of their cost. If the distortion is modelled accurately, then it can be easily removed. But without lens distortion removal, it is never possible to truly align images, or recover the full geometric information contained within aerial images.
AeroAlign takes standard photogrammetric lens distortion parameters, and uses those parameters to remove the non-linear distortions from the images. It can operate on single images, or in batch mode. It is smart enough to remember parameters, so that you don’t have to type them in every time. It is designed to be simple, efficient, and easy to use.
If you don’t know the distortion parameters for your camera and lens combination, we can also help you with that. We can recommend software for measuring lens distortion, or we can calibrate your camera for you. Please contact us for more information.
Very often it is necessary to align images from more than one camera to create multi-band images. This most commonly happens when natural colour imagery is captured from one camera, and near infrared (NIR) imagery is captured from another. However, the process for aligning images from multiple cameras is not necessarily easy.
AeroAlign simplifies the process of image alignment. The software will automatically align images, either in single image mode or batch mode, and even provide statistics for the alignment of each image pair. The software generates excellent results, even in images which have very little feature content.
If the images to be aligned have already undergone lens distortion removal, then the alignment will be even more accurate. We have consistently seen sub-pixel accuracies in images that we have tested.
Batch Image Processing
The most important feature of our batch image processing software is its batch processing capabilities. When presented with many pairs of images to align, the software can either generate new alignment parameters for every image pair, or it can recalculate the alignment parameters for each pair.
It can also be configured to revert to the default alignment when the calculated alignment is too far removed from the expected values. This can occur in regions where there are too few features to ensure successful matching. The result is that hundreds of images can be successfully aligned, fully autonomously.
Input and output
AeroAlign is compatible with TIF, PNG and JPG images (both 8 bit and 16 bit). It can process images from medium format cameras and has been used often with pairs of 80 megapixel images from a pair of Phase One cameras (RGB and NIR).
AeroAlign can output images in a range of formats (TIF, PNG, JPG) at different bit depths (8 bit and 16 bit). It can also create four band images (blue, green, red, near infrared) and NDVI images.