Subsign detection with region-growing from contrasted seeds

International audienceSpeed limit determination systems for cars based on vision are more and more developed. Roadsign detection is nowadays a well managed problem. However, in some situations this information is not sufficient to know the speed limitation. Restrictions are sometimes applicable and specified by subsigns. These small rectangles often provide essential information about the applicability scope (vehicle type, condition, lane, etc.) of speed limits. We present an approach of subsign localization based on region growing with an initial step of seed selection using morphological reconstruction. A comparison is also performed with three other techniques based on edge, color and graph on two databases gathering French and German subsigns. The obtained subsign correct detection is above 65%

Recognition of Supplementary Signs for Correct Interpretation of Traffic Signs

International audienceTraffic Sign Recognition (TSR) is now relatively well-handled by several approaches. However, traffic signs are often completed by one (or several) supplementary placed below. They are essential for correct interpretation of main sign, as they specify its applicability scope. The main difficulty of supplementary sub-sign recognition is the potentially infinite number of classes, as nearly any information potentially infinite number of classes, as nearly any information can be written on them. In this paper, we propose and evaluate a hierarchical approach for recognition of supplementary signs, in which the "meta-class" of the sub-sign (Arrow, Pictogram, Text or Mixed) is first determined. The classification is based on the pyramid-HOG feature, completed by dark area proportion measured on the same pyramid. Evaluation on a large database of images with and without supplementary signs shows that the classification accuracy of our approach 95% precision and recall. When used on output of our sub-sign specific detection algorithm, the global correct detection and recognition rate is 91%

Kontextsensitive Erkennung und Interpretation fahrrelevanter statischer Verkehrselemente

In dieser Arbeit werden Methoden und Verfahren zur Umwelterkennung und Situationsinterpretation entwickelt, mit denen statische Verkehrselemente (Verkehrszeichen und Ampeln) erkannt und im Kontext der Verkehrssituation interpretiert werden. Die Praxistauglichkeit der entwickelten Methoden und Verfahren wird durch umfangreiche Experimente demonstriert, bei denen auf die Verwendung realer Daten, kostengünstiger Sensorik und Echtzeitverarbeitung Wert gelegt wird