High quality ortho-rectified imagery
Rectified or orthographic or orthorectified photography is the creation of accurately dimensioned images. I am privileged to have applied these skills in some amazing places; Tower of London, Hampton Court Palace and numerous churches and monuments around the country. I have invested heavily over the years in cameras, lenses and software to provide high quality imagery.
There are several methods to create these scaled and corrected images. For a large facade the process would involve taking a series of images and using software to stitch these together, then applying coordinated points to these images to make them to scale. This process can also be used with aerial photography to provide a scaled image of a site.
Project Case Studies
Case Study – Rectified/Ortho imagery – Tower of London: Rectified photography was required of several moat walls and one large tall facade. A combination of ground level, high level using a mast and roof photographs were taken and processed. A control network was established to provide coordinates for the image rectification. Data was supplied to Historic Royal Palaces.
Case Study – Rectified/Ortho imagery – Colston Hall, Bristol: This particular project was for Levitt Bernstein Architects (link here…), this involved hiring a cherry picker and climbing in and photographing the front and rear facades, what could possibly go wrong? As it turned out the project went well, with no dramas, apart from being hoisted very high up in a rickety basket! Being November 2017 the day was quite short and the sun in the morning wasn’t kind casting lots of shadows. The images from the Canon DSLR were very good and both facades came out extremely well with great definition.
Case Study – Rectified/Ortho imagery – St. Peter & St. Paul’s Church, Albury: This was a full measured survey of the church with a requirement for ortho/rectified imagery of the internals, a high resolution DSLR was used on a mast to capture the low and high levels. Dimensions were taken and the images were corrected and rectified to these measurements.
Orthorectification is the process of removing the effects of image perspective and slope to create a planimetrically correct image. The resultant orthorectified image has a constant scale wherein features are represented in their ‘true’ positions. This allows for the accurate direct measurement of distances, angles, and areas.
This is a great way to record in high detail a facade of a building, monument, church or perhaps a roof or floor. The corrected images can be inserted into a CAD package using it’s world coordinates. For example you may have a large historic facade and want to inspect and record any defects, the image can be placed into CAD and any notes added over the image. Perhaps a large area of historic floor, paving or even a roof, the same process can be applied.
It’s often referred to as rectified photography, orthophotography, orthorectification and orthomosaic imagery.
If you require any further information or have a project in mind, please do not hesitate to get in touch…
I am passionate about photography, if you have time please take a look at my photography website which has more examples and drone imagery… www.ispypixel.co.uk