Dirk Meijer

Leiden University | LEI · Leiden Institute of Advanced Computer Science

This work introduces RADIUS, a framework for anomaly detection in sewer pipes using stereovision. The framework employs three-dimensional geometry reconstruction from stereo vision, followed by statistical modeling of the geometry with a generic pipe model. The framework is designed to be compatible with existing workflows for sewer pipe defect det...

Sewer pipes are commonly inspected in situ with CCTV equipment. The CCTV footage is then reviewed by human operators in order to classify defects in the pipes and make a recommendation on possible interventions. This process is both labor-intensive and error-prone. Other researchers have suggested machine learning techniques to (partially) automate...

AdaBoost is an iterative algorithm to construct classifier ensembles. It quickly achieves high accuracy by focusing on objects that are difficult to classify. Because of this, AdaBoost tends to overfit when subjected to noisy datasets. We observe that this can be partially prevented with the use of validation sets, taken from the same noisy trainin...

This paper presents a method to automatically assess the accuracy of image registration. It is applicable to images in which vessels are the main landmarks such as fundus images and angiography. The method simultaneously exploits not only the position, but also the intensity profile across the vasculatures. The accuracy measure is defined as the en...