New tech transforms aerial photos into 3D images

Stacy Shi

Hundreds of thousands of traditional paper-based aerial photos will be transformed into 3D digital data and images by the end of the year using the brand-new Digital Aerial Photograph Interpretation System of the Civil Engineering and Development Department's Geotechnical Engineering Office.

The new HK$6.5 million system, backed by the Innovation and Technology fund, will offer one-stop storage of 3D aerial photos and enable online users to search, view and download digital copies.

Aerial photos enable engineers to map geology and geomorphology of rock types, compile the catalog of man-made slopes, ascertain the history of land development, and assist in land planning and management, said Jenny Yeung Fei, deputy head of Geotechnical Engineering Office (Planning & Testing).

Presently, the GEO's Aerial Photograph Library houses over 370,000 aerial photos - the largest collection among government departments. Nearly 17,000 of these are loaned out to other departments and the engineering sector each month.

Engineers have had to visit the library in person to borrow photos and use special equipment to interpret them.

Amid the gradual full digitization of the Lands Department's aerial photo printing service, the GEO began developing its new system in late 2022.

Its first phase saw 70,000 images transform from paper-based pictures into 3D digital data and imagery.

"With the new system, multiple users can view the same set of photos simultaneously, unlike traditional paper-based aerial photos, which can only serve one user at a time," said chief technical engineer Florence Ko Wan-yee.

Regarding its application on slope safety management, Yeung said the new system can support the geotechnical industry, allowing it to borrow photos anytime for interpretation, improving efficiency. The system will initially be accessible to government departments and engineering personnel engaged in government projects. The GEO would continue to provide loan services for paper-based aerial photographs, Yeung added.

The general public still need to visit the Lands Department's Hong Kong Map Services 2.0 website to view or purchase aerial photos.

stacy.shi@singtaonewscorp.com