... continued from PART 2 - TAKING THE PICTURES
When we return to our labs from a photo shoot - the on location work is over and now the real magic has to begin. The 7 individual images taken for each 360 panorama need to be merged together into one 360 degree by 180 degree image known as an equirectangular projection. The process of doing this is known as stitching. You will need an image editing package such as Adobe Photoshop or Corel Photopaint to manually edit and tweak the photos and then a panoramic stitching suite such as Autopano Giga to stitch the images together.
The stitching software has to do a number of functions - firstly it has to know what type of lens took the photos - this is sometimes included in the photo files themselves as exif data. It then corrects for lens distortion and then tries to find points on each image that correspond to points on the other images (known as control points). Then after it has pieced together the jigsaw puzzle it uses a blending technology to adjust the colours, white balance, contrast etc of each image until they all match.
If all goes well then you should end up with something like this.
The black nadir area at the bottom of the screen and the tripod legs and shadow will now need to be edited out. This can be done in 2 ways, firstly if the ground below is fairly feature-less or has a repeating pattern that can be copied from somewhere else or is totally random like grass or sand it is easy to "clone" over this area - however if there is a complex non reapeating pattern that needs to be continued then we will use the nadir photo we took while we were in the field. below you can see the extracted nadir area of the photo and the patched version with the tripod removed - in this case we used a combination of the nadir photo and some cloning.
Once you have an equirectangular projection that you are happy with you can do one of a few things with it. You can crop the image to the area that is suitable for you to use. you can convert it into a another type of projection or you can transform it into a 360 degree 3D Interactive Virtual Tour like this one.
On our Gallery page Panorama Gallery you can see many examples of an Equirectangular Projections that has been converted to 360 degree 3D Interactive Virtual Tours.
I hope this series of 3 articles has given you a small insight into the processes, equipment and software that are needed to produce these strange and wonderful pieces of artwork and maybe has inspired you to wanting 360 degree Panoramic Virtual Tours on your website.
If you would like any more information or a quote for a project you are considering please don't hesitate to talk to Roy Cruse on 07850 769 724 or email us at firstname.lastname@example.org