Photogrammetry is a passive contactless three-dimensional (3D) scanning technique, its high efficiency can be obtained using a relatively straightforward procedure with affordable equipment among the techniques of digitalization and real object 3D modeling. Many industries have taken advantage of this technique for reverse engineering in industrial quality inspection, biomechanical image, and archaeological documentation by utilizing different software, either commercial or open-source ones for the 3D reconstruction process. This paper compares only the performance of free photogrammetry software as a research effort to find the alternative and affordable tools to easily generate 3D solid model without using any costly 3D scanning and reconstructing technologies. Three open-source code tools for close-range photogrammetry of a human foot model were employed in this comparative study. In addition, the computational requirements are also taken into account for the viability of its photogrammetry process, the performance is also evaluated based on the realism of the generated 3D model. The comparison results of the tools discussed, such as those with more optimum model quality and shorter processing times due to the good quality of the generated 3D morphology shape are Agisoft Metashape and the total time 20 minutes. The accuracy in this study is range of 97.08 to 98.70%. These 3D models will be very useful in the field of medical rehabilitation to diagnose the morphology and foot posture in term of improving the posture of the child’s feet since early treatment.

A Comparative Study of Affordable Photogrammetry Software for Reconstructing 3D Model of a Human Foot

Lymphocytes mount protective immunity from infectious pathogens and from cancer. Their engagement by target antigens prompt activation, differentiation to effector cells and proliferation. These responses require energy that is generated by cellular metabolic processes, such as glycolysis and oxidative phosphorylation. Glycolysis occurs in the cytoplasm while oxidative phosphorylation occurs in the mitochondria. Energy in the form of adenosine triphosphate is generated from the uptake of glucose, amino acids and free fatty acids. Important recent evidence indicates that naive and activated lymphocytes and functionally distinct subsets preferentially use different metabolic pathways for their energy needs. Thus, effector Th17 cells primarily use glycolysis to generate energy required for their activities. Memory T and B cells and regulatory T cells, in contrast, rely on mitochondrial metabolism for their energy requirements. Naive T and B are in a quiescent state with small mitochondria. Extrinsic factors such as oxygen tension and intrinsic substrates can also influence the choice of metabolic pathways and functional flexibility. Studies of lymphocytes in disease states reveal alterations to choices of metabolic pathways from those in lymphocytes in healthy individuals. This article provides an overview of metabolic pathways required for energy generation during homeostasis and those induced during cellular differentiation and responses. Furthermore, we explore available evidence for altered metabolic pathway induction in some autoimmune diseases. A focus of the overview will be on helper T lymphocytes involved in chronic inflammation and those that regulate the immune response. The report alludes to the potential that targeting metabolic pathways could provide a strategy for the treatment of chronic diseases.

/pdf/metabolic-pathways-underpinning-lymphocyte-differentiation-1pkgz4aa6s.pdf

Metabolic Pathways Underpinning Lymphocyte Differentiation and Responses in Health and Disease

A colored 3D surface reconstruction method which effectively fuses the information of both depth and color image using Microsoft Kinect is proposed and demonstrated by experiment. Kinect depth images are processed with the improved joint-bilateral filter based on region segmentation which efficiently combines the depth and color data to improve its quality. The registered depth data are integrated to achieve a surface reconstruction through the colored truncated signed distance fields presented in this paper. Finally, the improved ray casting for rendering full colored surface is implemented to estimate color texture of the reconstruction object. Capturing the depth and color images of a toy car, the improved joint-bilateral filter based on region segmentation is used to improve the quality of depth images and the peak signal-to-noise ratio (PSNR) is approximately 4.57 dB, which is better than 1.16 dB of the joint-bilateral filter. The colored construction results of toy car demonstrate the suitability and ability of the proposed method.

Colored 3D surface reconstruction using Kinect sensor

Stereo vision in detecting human motion is an emerging research for automation, robotics, and sports science field due to the advancement of imaging sensors and information technology. The difficulty of human motion detection and tracking is relatively complex when it is applied to uncontrolled environment. In this paper, a hybrid filter approach is proposed to detect human motion in the stereo vision. The hybrid filter approach integrates Gaussian filter and median filter to reduce the coverage of shadow and sudden change of illumination. In addition, sequential thinning and thickening morphological method is used to construct the skeleton model. The proposed hybrid approach is compared with the normalized filter. As a result, the proposed approach produces better skeleton model with less influential effect on shadow and illumination. The output results of the proposed approach can show up to 86% of average accuracy matched with skeleton model. In addition, obtains approximately 94% of sensitivity measurement in the stereo vision. The proposed approach using hybrid filter and sequential morphology could improve the performance of the detection in the uncontrolled environment.

/pdf/stereo-vision-human-motion-detection-and-tracking-in-4wz7yfjdkv.pdf

Stereo vision human motion detection and tracking in uncontrolled environment

The creation of digital three dimensional (3D) spatial models for the real scenes using image collections is one of the interesting applications of computer vision. In this paper we present some experimental results for creating textured 3D models from image collections using open source software packages (i.e. VisualSFM, CMVS, SURE, MeshLab, Cloud Compare). The images can be picked up with different types of cameras, or using the different imaging systems like UAVs and Satellites. At first, we use VisualSFM which is a robust Structure from Motion software estimating the calibration parameters of all the images, and a sparse 3D point cloud. We present two alternative softwares for multi view dense stereo reconstruction (CMVS and SURE). CMVS and SURE are effective tools and can operate on the common desktop PCs. The obtained results with CMVS and SURE are visualized with Meshlab and Cloud Compare respectively. Again we used MeshLab for mesh generation and texture mapping based on Poisson’s filter for surface reconstruction and texturing tools available in Meshlab. General Terms Image processing, Computer Vision, 3D World Modelling From Image Collections.

/pdf/creating-textured-3d-models-from-image-collections-using-2cm2cu8tnx.pdf

Creating Textured 3D Models from Image Collections using Open Source Software

Image Reconstruction is generally an inverse problem, which helps to recover the original ideal image from its given bad version, such as one that is snowed by noise, blurred by atmospheric turbulence or that has some regions damaged. Image reconstruction techniques are used to create 3D images from sets of various projections. The task of generating fast and accurate 3D image reconstruction has found its application in the field of computer vision like robotics, entertainment, reverse engineering, augmented reality, human computer interaction and animation. This paper deals with detailed study on different methods and evaluation technique used in 3D image reconstructions like visualization technique, triangulation method, multiple kinect capturing system, handling photometric stereo and shadowing information in handling patches. Finally several recommendations on future study have been recommended based on recent issues like reconstructing geometrical shadow region, handling self shadow, shiny object, non-Iambatian surface, occlusion, reconstruction without the use of sensors like Global Positioning System (GPS) and Inertial Navigation System (INS).

SurenderNath SelvamParvathy

Papers

3D image reconstruction: Techniques, applications and challenges