Surveying firm wows architect clients by supporting laser scanning with HDR panoramic images
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For 40 years, Precision Surveys Limited has been offering a comprehensive consulting service orientated towards providing land-related information to both public and private sector clients throughout Ireland. It has more than 8,000 surveys completed which include building surveys, reference plans, legal and topographic surveys, laser scans, point cloud to BIM, control and engineering surveys, taking in charge and layouts.
Most architects and developers will use architectural photo-montages– computer generated images that show what a future scheme might look like. There are many factors and variables that mean the visual accuracy of such images can be questionable. Verified views or orthographic photos are architectural photo-montages which have been created to a high level of verifiable accuracy using collected survey data, precise photography and a strict recorded methodology.
"In the last three to four years we have been increasingly focused on laser scanning, particularly in conservationrelated projects," said David Buffini, director at Precision Surveys. "And many clients in this area are very keen to receive correlating panoramic images in addition to the laser scan data to provide an accurate, verified view of how a structure appears visually."
For its laser scanning projects, Precision Surveys use the Leica P40 scanner, which does offer the ability to take photographic images in addition to the scan, but this adds considerable time to the scanning process and can have significant limitations in low light conditions, where colour accuracy can be difficult to achieve.
"A single scan typically takes about three minutes, but adding a panoramic image typically adds an extra seven to eight minutes every time, which quickly adds up as you scan a complete site, which can involve hundreds of scans," said Buffini. "In addition, the scanner camera takes a lot of single-frame pictures, which are then stitched together later, and this can also impact on the final image quality if the light changes while images are being captured."
Enter iSTAR
Precision Surveys then came across iSTAR–the world’s highest resolution, fully automatic, 360-degree HDR camera. Machined from solid metal for robustness and accuracy, iSTAR precisely captures full spherical immersive images and high resolution panoramic data streams for fast, efficient visual documentation of almost any environment.
iSTAR uses four pre-calibrated camera sensors, fully synchronised to deliver a highly accurate 50MP spherical image with excellent high dynamic range (HDR). The camera is fast, with typical capture times averaging around 10 to 20 seconds for a five-exposure HDR image.
"The iSTAR’s speed of capture is a huge factor for us, coupled with its ease of use," said Buffini. "We can save a huge amount of time–sometimes as much as a full day–by simply being able to quickly take a 360 degree colour image after each scan. The images can then be easily integrated with the laser scan data to provide orthographic images that are visually stunning as well as accurate."
Processing and stitching the images is also fast iSTAR takes just seconds to conduct batch stitching. The camera can be mounted and deployed in various methods: terrestrial, with a standard tripod connected into the camera base; vehicle-mounted using roof bars; tripod suction feet, or; secured under a UAV for airborne mapping.
"I’d estimate that iSTAR has provided around a ten-fold improvement in productivity when it comes to collecting photographic imagery on a scanning project," said Buffini.
"And with the recent Leica integration that automates the import of iSTAR data, we expect to see even greater productivity improvements."
Delivering value in conservation
Precision Surveys has already delivered data for some compelling conservation projects using the iSTAR camera.
The orthographic images provide the basis on which the architect’s building information models will be refined in terms of geometry and texture. These virtual models will then be used to assist with the conservation strategy and the proposed detailed design of the refurbishment and extension.
"The architects we work with have been blown away by the quality of the imaging we provide through iSTAR," said Buffini. "The colour output is incredible and can actually provide our clients with such confidence in the accuracy of their images that they may not even require a confirmation visit to the site."
About NCTech NCTech designs and manufactures leading 360 degree reality imaging systems that automate and streamline the workflow of image documentation and can be used repeatedly, accurately, consistently by anyone anywhere. NCTech’s industrial-grade camera, iSTAR, is a fast, fully automatic, 50 megapixel, 360 degree HDR camera. Fully calibrated for high precision applications such as colourisation of laser scans or extracting photogrammetric measurements, iSTAR has multiple applications: from covert operations and police reporting of crime scenes to 3D laser documentation and asset management for the engineering and heritage sectors. In 2015, the company launched iris360, intended for aesthetic panoramic image capture and fully integrated with Google Maps’ new Street View app. NCTech is headquartered in Edinburgh, Scotland and is funded by Archangel Investors Ltd and the Scottish Co-Investment Fund. For more information, visit www. nctechimaging.com
A 3.230Mb PDF of this article as it appeared in the magazine complete with images is available by clicking HERE