Stitching aerial photos
Making beautiful 360-degree aerial panoramic images is often very difficult. The main problem lies in the fact that the point of view is constantly moving.
Parasailing, delta wings, helicopters, airplanes… it doesn’t matter what you use to take the images but your point of view is rarely stable in relation to the ground (it is constantly changing altitude, position, etc.). This is why it’s always difficult to assemble these images later.
Therefore, getting an aerial panoramic image with a resolution in the gigapixel range really seems like mission impossible!
In fact, this isn’t the case at all! This is what we will learn in this tutorial.
Example : L'Alpe d'Huez, 1.8 Gigapixels
- Photographer: Bernard Vallet (photographer used to shooting very large panoramas).
- Location: L'Alpe d'Huez
- Date: Summer 2010
- Medium-format Leaf AFi-II 10, 55 Megapixels (giving each image a resolution of 5992 x 9326 pixels).
- Ultra-light aircraft (attempting to create stability by making several rounds during shooting).
- Number of images: 94 photographs
The stitching with Autopano Giga
Use default settings but uncheck cleaning of bad points because the clean threshold is not adapted to wide viewpoint shifting during shooting:
Autopano Giga creates the following panorama:
The result isn’t very good, but why?
It’s just because the point of view has moved too much.
In order to solve this problem, you need to optimise the viewpoint scope (previously called multiple viewpoints, only available in Autopano Giga), found within the Scopes tab of the control points editor.
Then, run a quick optimization.
Autopano will then create a panoramic image like this one:
The stitching is not perfect. Autopano is not capable of correcting all parallax errors, which are unavoidable when there are changes in viewpoint.
The animation below shows the effect:
- The images are perfectly stitched around the mountain in the foreground.
- The image background is distorted, which is natural considering the viewpoint changed during shooting.
The Anti-ghost of Autopano Giga is very efficient at removing this issue, even though it will never be able to completely solve the problem.
Therefore, you still need to make some very localized, quick retouching using Photoshop.
Result into virtual tour