Core Concepts
The authors present the development of new efficient visual markers based on the OILU numbering system, which offer improved robustness against acquisition and geometric distortions compared to existing square and circular markers.
Abstract
The paper introduces a new visual marker system based on the OILU numbering system, which associates basic patterns (O, I, L, U) to decimal digits. The OILU markers are designed as square markers composed of superimposed OILU symbols, allowing the generation of a rich panel of unique identifiers.
The key highlights and insights are:
The OILU numbering system allows producing multi-faceted numbers, where each facet represents a different numerical value. This property is exploited to design the new visual markers.
The spiral topology of the OILU markers enables the use of level set methods to generate an accurate distance map for marker identification. This approach is more robust to distortions compared to traditional dot-matrix markers.
Extensive experiments were conducted to evaluate the robustness of the OILU markers against various distortions, including noise, blur, and viewing angle changes. The results demonstrate satisfactory performance, even under high levels of distortion.
The authors note that the OILU system can be used to generate not only square markers, but also circular and dotted markers with similar coding capacities. This flexibility is an interesting avenue for future work.
While the current level set-based identification method is computationally expensive, the authors are working on a faster approach to enable real-time marker detection and identification.
Overall, the OILU visual markers show promise as a robust alternative to existing marker systems, particularly for applications requiring accurate localization and augmented reality.
Stats
The processing time for marker detection and identification was around 40 ms on a typical MacBook with a 2.9 GHz Intel Core i5 processor and 8 GB of RAM.
Quotes
"The main interesting thing with this symbolic is that, it allows superimposing symbols in pyramidal form without losing the value of the constructed numbers."
"Multi facets numbers have interesting applications in the large field of data processing, but in our case, they are mainly exploited for the design of new efficient square OILU markers."