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The existing methods for measuring the shape of the human body in motion are limited in their practical application owing to immaturity, complexity, and/or high price. Therefore, we propose a method based on structured light supported by multispectral separation to achieve multidirectional and parallel acquisition. Single-frame fringe projection is employed in this method for detailed geometry reconstruction. An extended phase unwrapping method adapted for measurement of the human body is also proposed. This method utilizes local fringe parameter information to identify the optimal unwrapping path for reconstruction. Subsequently, we present a prototype 4DBODY system with a working volume of 2.0 &times, 1.5 &times, 1.5 m3, a measurement uncertainty less than 0.5 mm and an average spatial resolution of 1.0 mm for three-dimensional (3D) points. The system consists of eight directional 3D scanners functioning synchronously with an acquisition frequency of 120 Hz. The efficacy of the proposed system is demonstrated by presenting the measurement results obtained for known geometrical objects moving at various speeds as well actual human movements.

The chapter presents an automatic method for an optical three-dimensional markerless shape measurement and assessment of pectus excavatum severity. The body shape measurement is conducted with use of a four-directional measurement system based on structured light projection method (namely Temporal Phase Shifting TPS and modified Gray code projection). The system set-up is described and the typical measurement parameters are given. Three-dimensional point clouds acquired during the measurement are being automatically processed and analyzed in order to calculate the value of trunk deformation index (I3ds) that shows correlation with CT Haller Index widely used for assessment of pectus excavatum. Three-dimensional structured light measurement of funnel chest is safe allowing to perform this test without any risk to the patient.

Contains fulltext : 118760.pdf (Publisher’s version ) (Open Access) We report on a structured light-scanning system, the OGX|4DSCANNER, capable of capturing the surface of a human body with 2 mm spatial resolution at a 60 Hz frame-rate. The performance of modeling the human lower body dynamics is evaluated by comparing the system with the current gold standard, i.e., the VICON system. The VICON system relies on the application of reflective markers on a person's body and tracking their positions in three-dimensional space using multiple cameras [optical motion capture (OMC)]. For the purpose of validation of the 4DSCANNER, a set of "virtual" markers was extracted from the measured surface. A set of musculoskeletal models was built for three subjects based on the trajectories of real and virtual markers. Next, the corresponding models were compared in terms of joint angles, joint moments, and activity of a number of major lower body muscles. Analyses showed a good overall agreement of the modeling outcome. We conclude that the 4DSCANNER within its limitations has the potential to be used in clinical gait analysis instead of optical marker-based systems. The advantage of the 4DSCANNER over OMC solutions is that it does not burden patients with time-consuming marker application. This study demonstrates the versatility of this measurement technique. 01 mei 2013

The transmission and analysis of video is frequently used for a variety of applications outside the entertainment sector, and it is generally used to perform specific tasks. The Quality of Experience (QoE) concept for video content used for entertainment differs significantly from the QoE of video used for recognition tasks, because in the latter case the subjective satisfaction of the user depends on achieving the given task, e.g. event detection or object recognition. Additionally, the quality of video used by a human observer is distinct from objective video quality used in computer processing — Computer Vision. The VQiPS (Video Quality in Public Safety) Working Group, established in 2009 and supported by the U.S. Department of Homeland Security's Office for Interoperability and Compatibility, has been developing a user guide for public safety video applications. According to VQiPS, the ability to achieve a recognition task is influenced by many parameters, and five of them have been selected as being of particular importance. They are: usage time-frame, discrimination level, target size, lighting level, and level of motion. These parameters form what are referred to as Generalized Use Classes, or GUCs. The aim of our research was to develop algorithms that would automatically support classification of input sequences into one of the GUCs. Target size and lighting level parameters were approached. The described experiment reveals the ambiguity and hesitation of the experts during the manual target size determination process. However, the developed automatic methods of target size classification make it possible to determine GUC parameters with satisfactory efficiency at compliance levels of 70% with end-users opinion. Lighting levels of the entire sequence can be classified with an efficiency reaching 93%.

Currently, a lot of different scanning techniques are used for 3D imaging of human body. Most of existing systems are based on static registration of internal structures using MRI or CT techniques as well as 3D scanning of outer surface of human body by laser triangulation or structured light methods. On the other hand there is an existing mature 4D method based on tracking in time the position of retro-reflective markers attached to human body. There are two main drawbacks of this solution: markers are attached to skin (no real skeleton movement is registered) and it gives (x, y, z, t) coordinates only in those points (not for the whole surface). In this paper we present a novel multidirectional structured light measurement system that is capable of measuring 3D shape of human body surface with frequency reaching 60Hz. The developed system consists of two spectrally separated and hardware-synchronized 4D measurement heads. The principle of the measurement is based on single frame analysis. Projected frame is composed from sine-modulated intensity pattern and a special stripe allowing absolute phase measurement. Several different geometrical set-ups will be proposed depending on type of movements that are to be registered.

The paper presents an optical three-dimensional shape measurement system and an automatic method for assessment of pectus excavatum severity based on the measurement results. The measurement system consists of four directional modules utilizing structured light projection method (namely temporal phase shifting TPS and modified Gray code projection) to capture the shape of body surface of the patients. The measurement result is a three-dimensional point cloud representing the skin surface. The system setup is described and the typical measurement parameters are given. The automated data analysis path is explained. Its main stages are: point cloud segmentation, normalization of trunk orientation, cutting the model into slices, analysis of each slice shape, selecting the proper slice for the assessment of pectus excavatum of the patient and calculating its shape parameter. The analysis does not require any initial processing (e.g. surface fitting or mesh building) as it is conducted on raw 3-D point cloud data resulting from the measurement. A new shape parameter (I3ds) was developed that shows correlation with CT Haller Index widely used for assessment of pectus excavatum. Preliminary clinical results are presented.

We present an automatic method for assessment of pectus excavatum severity based on an optical 3-D markerless shape mea- surement. A four-directional measurement system based on a struc- tured light projection method is built to capture the shape of the body surface of the patients. The system setup is described and typical mea- surement parameters are given. The automated data analysis path is explained. Their main steps are: normalization of trunk model orien- tation, cutting the model into slices, analysis of each slice shape, se- lecting the proper slice for the assessment of pectus excavatum of the patient, and calculating its shape parameter. We develop a new shape parameter I3ds that shows high correlation with the computed to- mography CT Haller index widely used for assessment of pectus excavatum. Clinical results and the evaluation of developed indexes are presented. © 2009 Society of Photo-Optical Instrumentation Engineers.

The recent development of electro-optical instrumentation allowed constructing 4D (3D + time) structure-light scanners which may be used to measure the surface of human body in motion. The main advantage of structure-light scanners is the possibility of capturing data from the whole measured body surface, while traditional marker-based systems acquire data only form markers attached to skin of the examined patient. The paper describes new parameters describing the local shape of measured surface. The distribution maps of these parameters allow discrimination of various surface types and in effect localization and tracing of under-skin anatomical structures in time. The presented parameters give similar results to well-known curvatures but are easier and quicker to calculate. Moreover the calculation process of the new parameters is more numerically stable itself. The developed path of processing and analysis of 4D measurement data has been presented. It contains the following stages: data acquisition, volumetric model creation, calculations of shape parameters, selecting areas of interest, locating and tracing of anatomical landmarks. Exemplary results of application of developed parameters and methods to real measurement and computer generated data are also presented.

Orthopedics and neurosciences are fields of medicine where the analysis of objective movement parameters is extremely important for clinical diagnosis. Moreover, as there are significant differences between static and dynamic parameters, there is a strong need of analyzing the anatomical structures under functional conditions. In clinical gait analysis the benefits of kinematical methods are undoubted. In this paper we present a 4D (3D + time) measurement system capable of automatic location of selected anatomical structures by locating and tracing the structures' position and orientation in time. The presented system is designed to help a general practitioner in diagnosing selected lower limbs' dysfunctions (e.g. knee injuries) and also determine if a patient should be directed for further examination (e.g. x-ray or MRI). The measurement system components are hardware and software. For the hardware part we adapt the laser triangulation method. In this way we can evaluate functional and dynamic movements in a contact-free, non-invasive way, without the use of potentially harmful radiation. Furthermore, opposite to marker-based video-tracking systems, no preparation time is required. The software part consists of a data acquisition module, an image processing and point clouds (point cloud, set of points described by coordinates (x, y, z)) calculation module, a preliminary processing module, a feature-searching module and an external biomechanical module. The paper briefly presents the modules mentioned above with the focus on the feature-searching module. Also we present some measurement and analysis results. These include: parameters maps, landmarks trajectories in time sequence and animation of a simplified model of lower limbs.

It is expected that the next generation of full 3D optical scanning systems will be able to measure volumetric objects in motion. Standard data representations like point clouds or sets of triangle meshes, which are used nowadays for static 3D objects, will no longer be an efficient solution in this field. Systems of this kind will have to use other data processing and representation methods. We propose our own solution in this paper, using an arbitrary full 3D mesh which is scaled and wrapped around a merged point cloud obtained from the measurements, instead of a standard point cloud representation. This solution was specifically prepared for a prototype of a full-field 4D scanning system. This system is based on a dynamic laser triangulation. Four scanners capture a surface of a moving object from four different directions simultaneously. They are calibrated in time and space so finally we can obtain a full 3D object surface which changes in time. In this paper we present some details of the scanning system, 4D surface representation, general 4D data processing pipeline, developed algorithms and we finally show some exemplary results of our work in this field.

New optical full-field shape measurement systems allow transient shape capture at rates between 15 and 30 Hz. These frequency rates are enough to monitor controlled movements used e.g. for medical examination purposes. In this paper we present a set of algorithms which may be applied for processing of data gathered by fringe projection method implemented for lower limbs shape measurement. The purpose of presented algorithms is to locate anatomical structures based on the limb shape and its deformation in time. The algorithms are based on local surface curvature calculation and analysis of curvature maps changes during the measurement sequence. One of anatomical structure of high medical interest that is possible to scan and analyze, is patella. Tracking of patella position and orientation under dynamic conditions may lead to detect pathological patella movements and help in knee joint disease diagnosis. Therefore the usefulness of the algorithms developed was proven at examples of patella localization and monitoring.

The basic methodologies used in animation are presented and their most significant problems connected with combining real and virtual worlds are recognised. Measured objects are classified into groups based on their mechanical properties and behaviour. The optical methods of shape and movement parameters determination adequate for fast virtual object generation are presented. Combination of various fringe projection techniques with photogrammetry is proposed to calculate the temporal shape and position of the object points. The spatio-temporal analysis of a projected fringe pattern delivers information about object shape and its out-of-plane deformation. The shape of measured object is calculated based on algorithm spatial carrier phase shifting technique. The analysis of marker dislocations during the measurement provides information about object shifts within the measurement volume. Combined information about object shape and its dislocation during the measurement enable to generate a virtual model that can be used to generate e.g.: realistic animation. The short comparison between proposed method and currently available systems is given and exemplary results of measurements are presented. The further directions of development of proposed techniques are presented.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Faulty postures, scoliosis and sagittal plane deformities should be detected as early as possible to apply preventive and treatment measures against major clinical consequences. To support documentation of the severity of deformity and diminish x-ray exposures, several solutions utilizing analysis of back surface topography data were introduced. A novel approach to automatic recognition and localization of anatomical landmarks of the human back is presented that may provide more repeatable results and speed up the whole procedure. The algorithm was designed as a two-step process involving a statistical model built upon expert knowledge and analysis of three-dimensional back surface shape data. Voronoi diagram is used to connect mean geometric relations, which provide a first approximation of the positions, with surface curvature distribution, which further guides the recognition process and gives final locations of landmarks. Positions obtained using the developed algorithms are validated with respect to accuracy of manual landmark indication by experts. Preliminary validation proved that the landmarks were localized correctly, with accuracy depending mostly on the characteristics of a given structure. It was concluded that recognition should mainly take into account the shape of the back surface, putting as little emphasis on the statistical approximation as possible.

Four-dimensional (4D) (3D+time) measurement systems make it possible today to measure objects while moving and deforming. One of the fields where 4D systems prove themselves useful is medicine--particularly orthopedics and neural sciences--where measurement results may be used to estimate dynamic parameters of a patient's movement. Relatively new in 4D, optical full-field shape measurement systems capture more data than standard marker-based systems and open new ways for clinical diagnosis. However, before this is possible, the appropriate 4D data processing and analysis methods need to be developed. We present a new data analysis path for 4D data input as well as new shape parameters describing local features of a surface. The developed shape parameters are easier and quicker to calculate than standard surface parameters, such as curvatures, but they give results that are very similar to the latter. The presented 4D data analysis path allows characteristic areas on the body, so-called anatomical landmarks, to be located and traces them in time along the measurement sequence. We also present the general concepts and describe selected steps of the developed 4D data analysis path. The algorithms were implemented and tested on real and computer-generated data representing the surface of lower limbs. Finally, we give sample processing and analysis results.

Features of trunk and postural deformations are clinically observed to detect related musculoskeletal disorders, namely scoliosis, kyphosis or other thoracic deformities. High variability and controversial reliability of results of postural screening require new solutions to be employed. Standardized criteria for correct body posture are needed for further studies. The aim of this work was to present the current status of development of the 3D diagnostic system for anatomical structures detection. The designed system is based on a parameterized method of body surface analysis for automated measurement of the three-dimensional shape of patient’s trunk. This system uses structured light to measure patient’s body in 3D space by projection of a set of raster images on its surface. A unique feature of the presented system is the ability to operate on remote sites and carry out measurement interpretation by telemedicine utilizing a data warehouse. The system comprises of three independent modules which deal with measurement, data archiving and its analysis. Communication between modules is performed over the TCP/IP protocol, incorporating two different channels for each client, dedicated to two kinds of data - text channel, for transmission of XML documents used for delivering commands and information and binary channel for the transfer of large binary data, such as clouds of points or photographs. Presented modules altogether allow to measure the full shape of subject’s 3D surface along with measurement data storage and analysis for support of screening and diagnosis.

New image processing methods and active photonics apparatus have made possible the development of relatively inexpensive optical systems for complex shape and object measurements. We present dynamic 360° scanning method for analysis of human lower body biomechanics, with an emphasis on the analysis of the knee joint. The anatomical structure (of high medical interest) that is possible to scan and analyze, is patella. Tracking of patella position and orientation under dynamic conditions may lead to detect pathological patella movements and help in knee joint disease diagnosis. The processed data is obtained from a dynamic laser triangulation surface measurement system, able to capture slow to normal movements with a scan frequency between 15 and 30 Hz. These frequency rates are enough to capture controlled movements used e.g. for medical examination purposes. The purpose of the work presented is to develop surface analysis methods that may be used as support of diagnosis of motoric abilities of lower limbs. The paper presents algorithms used to process acquired lower limbs surface data in order to find the position and orientation of patella. The algorithms implemented include input data preparation, curvature description methods, knee region discrimination and patella assumed position/orientation calculation. Additionally, a method of 4D (3D + time) medical data visualization is proposed. Also some exemplary results are presented.