Using Colors to Detect Structural Components in Digital Pictures

This article describes a method of recognizing the presence of structural components in a digital picture taken at a construction site. The objective is to introduce image recognition into the construction management process in order to enhance the control of the performance at a construction site. The developed system can detect a component in a picture through its color and position. An algorithm capable of tracing the edges of a shape in a digital picture is introduced. A procedure to collect objects using this edge detector is presented. A complete description of procedures written in Delphi 5 to store a set of objects detected in a picture is included. The component‐recognition engine presented in this article is an important part of a system called PHOTO‐NET that was designed to monitor progress in a construction site and as such constitutes a unique application in the context of construction management.