Rectified photography
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 drones, cameras, lenses and software to provide high quality imagery.
The Process
There are several methods to create these scaled and corrected images. For a large facade the best 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.
All photography projects are in accordance with Historic England specifications/guidelines.
Projects
Tower of London – Rectified/Ortho imagery: 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.
ACS Hillingdon: This was part of a measured survey of three heritage rooms within the College Mansion, photogrammetry was used to record the ceilings and the internal walls. From this, detailed CAD drawings were provided of the internal walls and reflected ceiling plans, the imagery was included as part of the final deliverable. See below for some examples >>
Colston Hall – Rectified/Ortho imagery: 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.
External rectified image examples
Internal rectified image examples
FAQ
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, ceiling, internal walls or a 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