Juho-Pekka Virtanen

Comparison of the Selected State-Of-The-Art 3D Indoor Scanning and Point Cloud Generation Methods

Accurate three-dimensional (3D) data from indoor spaces are of high importance for various applications in construction, indoor navigation and real estate management. Mobile scanning techniques are offering an efficient way to produce point clouds, but with a lower accuracy than the traditional terrestrial laser scanning (TLS). In this paper, we first tackle the problem of how the quality of a point cloud should be rigorously evaluated. Previous evaluations typically operate on some point cloud subset, using a manually-given length scale, which would perhaps describe the ranging precision or the properties of the environment. Instead, the metrics that we propose perform the quality evaluation to the full point cloud and over all of the length scales, revealing the method precision along with some possible problems related to the point clouds, such as outliers, over-completeness and misregistration. The proposed methods are used to evaluate the end product point clouds of some of the latest methods. In detail, point clouds are obtained from five commercial indoor mapping systems, Matterport, NavVis, Zebedee, Stencil and Leica Pegasus: Backpack, and three research prototypes, Aalto VILMA , FGI Slammer and the Wurzburg backpack. These are compared against survey-grade TLS point clouds captured from three distinct test sites that each have different properties. Based on the presented experimental findings, we discuss the properties of the proposed metrics and the strengths and weaknesses of the above mapping systems and then suggest directions for future research.

Intelligent Open Data 3D Maps in a Collaborative Virtual World

Three-dimensional (3D) maps have many potential applications, such as navigation and urban planning. In this article, we present the use of a 3D virtual world platform Meshmoon to create intelligent open data 3D maps. A processing method is developed to enable the generation of 3D virtual environments from the open data of the National Land Survey of Finland. The article combines the elements needed in contemporary smart city concepts, such as the connection between attribute information and 3D objects, and the creation of collaborative virtual worlds from open data. By using our 3D virtual world platform, it is possible to create up-to-date, collaborative 3D virtual models, which are automatically updated on all viewers. In the scenes, all users are able to interact with the model, and with each other. With the developed processing methods, the creation of virtual world scenes was partially automated for collaboration activities.

Luminance-Corrected 3D Point Clouds for Road and Street Environments

A novel approach to evaluating night-time road and street environment lighting conditions through 3D point clouds is presented. The combination of luminance imaging and 3D point cloud acquired with a terrestrial laser scanner was used for analyzing 3D luminance on the road surface. A calculation of the luminance (cd/m2) was based on the RGB output values of a Nikon D800E digital still camera. The camera was calibrated with a reference luminance source. The relative orientation between the luminance images and intensity image of the 3D point cloud was solved in order to integrate the data sets into the same coordinate system. As a result, the 3D model of road environment luminance is illustrated and the ability to exploit the method for evaluating the luminance distribution on the road surface is presented. Furthermore, the limitations and future prospects of the methodology are addressed. The method provides promising results for studying road lighting conditions in future lighting optimizations. The paper presents the methodology and its experimental application on a road section which consists of five luminaires installed on one side of a two-lane road in Otaniemi, Espoo, Finland.

Rapid prototyping a tool for presenting 3-dimensional digital models produced by terrestrial laser scanning

Rapid prototyping has received considerable interest with the introduction of affordable rapid prototyping machines. These machines can be used to manufacture physical models from three-dimensional digital mesh models. In this paper, we compare the results obtained with a new, affordable, rapid prototyping machine, and a traditional professional machine. Two separate data sets are used for this, both of which were acquired using terrestrial laser scanning. Both of the machines were able to produce complex and highly detailed geometries in plastic material from models based on terrestrial laser scanning. The dimensional accuracies and detail levels of the machines were comparable, and the physical artifacts caused by the fused deposition modeling (FDM) technique used in the rapid prototyping machines could be found in both models. The accuracy of terrestrial laser scanning exceeded the requirements for manufacturing physical models of large statues and building segments at a 1:40 scale.

Tutorial: Road Lighting for Efficient and Safe Traffic Environments

ABSTRACT This article discusses various aspects of outdoor lighting energy efficiency by means of new light sources and smart lighting systems. We will also discuss visibility, traffic flow, safety, and environmental and economic aspects. The use of an optimum level of road lighting maximizes the contrast between the background and the object to be seen. This suggests that the combined effect of road lighting and car headlights should be taken into account. Solutions for future measurement need to include 3D modeling of the lighting environment and mesopic photometry. The life cycle environmental impacts of high-pressure sodium (HPS) and light emitting diode (LED) luminaires were found to be on a similar level, but it is expected that LED luminaires will surpass HPS luminaires in environmental friendliness across the whole life cycle in the future. The energy-saving potential is based on new energy-efficient technology, reduced burning hours with smart control, and new lighting dimensioning. The energy saving potential when replacing HPS lamps with LED luminaires is 31% with current technology and 66% with improved technology in the future. Further energy savings are achievable with reduced burning hours enabled with smart lighting. Altogether, the energy-saving potential of the future LED luminaire is 83% compared to current HPS luminaires.

Modern empirical and modelling study approaches in fluvial geomorphology to elucidate sub-bend-scale meander dynamics

Major developments in theory and modelling techniques have taken place within the past couple of decades in the field of the fluvial geomorphology. In this review, we examine the state-of-the-art empirical and modelling approaches and discuss their potential benefits and shortcomings in deepening understanding of the sub-bend-scale fluvial geomorphology of meander bends. Meandering rivers represent very complex 3D flow and sedimentary processes. We focus on high-resolution techniques which have improved the spatial and temporal resolution of the data and thereby enabled investigation of processes, which have been thus far beyond the capacity of the measurement techniques. This review covers the measurement techniques applied in the field and in laboratory circumstances as well as the close-range remote sensing techniques and computational approaches. We discuss the key research questions in fluvial geomorphology of meander bends and demonstrate how the contemporary approaches have been and could be applied to solve these questions.

Camera preparation and performance for 3D luminance mapping of road environments

Road lighting measurements are executed with stationary imaging luminance photometry. In these measurements, a digital camera is utilized to create 2D luminance data maps of the scenery. We consider the third dimension to be a meaningful advancement for luminance data presentation and analysis. Hence, we present the preparation for a digital camera in order to use it as an imaging luminance photometer combined with a laser scanning system. The target area of use for our measuring system is the night-time road environment. We assessed the limiting factors when integrating luminance photometry into laser scanning systems. We achieved the initial luminance data and 3D point cloud integration for terrestrial laser scanning (TLS) and mobile laser scanning (MLS) systems. In stationary luminance measurements, the target luminance range was achieved. For mobile measurements, the target luminance range was compromised. The mobile measurement luminance range was limited because a long exposure time could not be used. A short exposure time was compensated for by increasing the sensor sensitivity, which reduced the signal-to-noise ratio. In mobile measurements, the luminance range can be extended towards the low end only by reducing the movement velocity or by accepting more motion blur in the measurements.

Customer Journey Mapping of an Experience-Centric Service by Mobile Self-reporting: Testing the Qualiwall Tool

A focus on the user experience and user-centric perspective are considered to be essential in today’s product and service development processes. Technological advancements during the last two decades have made user studies based on digital, mobile self-reporting possible. The goal of this study is to report on our experiences using a mobile self-reporting tool called Qualiwall for the customer journey mapping of an experience-centric service. The results indicate that the Qualiwall tool is especially suitable for mapping the customer experiences because it enables the collection of rich, real-time and in-situ data; however, it also possesses certain disadvantages. To arrive at more general conclusions, future research will focus on piloting the Qualiwall tool in other service-related user research situations as well.

DEVELOPING NATURAL AND INTUITIVE VIDEO-MEDIATED COLLABORATION — NIVMC SYSTEM

This article describes design challenges of a novel concept enabling natural and intuitive video-mediated collaboration. Typical video-mediated communication systems do not enable deictic gestures ...

Natural and Intuitive Video Mediated Collaboration

This paper presents a project which introduces a novel concept and technical implementation of a video mediated collaboration system. The starting point was to provide tools suitable for professionals particularly in the field of design and engineering. The core of the concept is to create a permanent connection between two remote locations and to combine live video screen and interactive table surface. The aim is to use the best features of existing videoconferencing solutions, smart whiteboards and collaborative file sharing systems. The technical solution is based on utilisation of existing components and low cost software. The first prototypes suggest that this type of system has more intuitive and natural user interface compared to current solutions. With future field testing the challenges concerning the application environment can be better met.