The distance measurement based on corner detection for rebar spacing in engineering images

The acceptance of binding and rebar installation is the last and vital step in construction engineering. However, there are many environmental constraints in the acceptance of the quality of rebar binding, which affect the acceptance. To address these problems, this study proposes an image-based intelligent distance measurement system, proving convenient for workers to measure long distances. The solution could effectively improve the measurement range during the acceptance process of rebar binding. The proposed method is divided into three steps. In the first step, a laser rangefinder was employed to measure the distance between the camera and the rebar; in the second step, the corner detector, based on the improved Harris corner detection algorithm, was used to detect the corners of the rebar images; and in the third step, the value of laser distance measured and the pixel value obtained by the corner detector was adopted for distance measurement. The method our proposed has a positive impact on the quality acceptance process of rebar binding, which can greatly improve the acceptance efficiency and save time.