Amateur Digital Cameras Research Articles

Upoređenje rezultata UAV fotogrametrije na kalibracionom poligonu "Debeljača" dobijenih primenom različitih softverskih sistema

The aim of this paper is to present a comparative analysis of the results obtained by UAV photogrammetry on the calibration polygon "Debeljača", and by using two different software systems: AgiSoft PhotoScan and Trimble INPHO UASMaster. The paper presents the impact analysis and the potential evaluation of errors in the UAV photogrammetric block, obtained by DSLR - Digital Single-Lens Reflex amateur digital camera with unknown internal orientation and unknown distortion values. Blocks were formed using SfM - Structure from Motion approach, implemented in given software systems. A large number of reliable control points on the calibration polygon enabled the analysis of error propagation in the block for different scenarios of distribution of the ground control points, as well as the assessment of the geometric quality of the formed models.

Using RTK and VRS in direct geo-referencing of the UAV imagery

Direct Geo-Referencing is a new technique in photogrammetry, especially in the aerial photogrammetry. Unlike the Aerial Triangulation “AT”, this method does not require Ground Control Points “GCPs”, to process aerial photographs into desired ground coordinates systems. Compared with the old method, this method has four main advantages: faster field work, faster data processing, simple workflow and less cost. Generally, direct geo-referencing using two systems, Global Navigational Satellite Systems “GNSS” and Inertial Navigational System “INS”. GNSS recording the camera coordinates “X, Y, Z”, and INS recording the camera orientation angles “w, φ, k” at the time of exposure. These parameters merged and are provided to each photograph in the processing stage.The current paper investigates the using GNSS system for providing the linear exterior orientation “EO” parameters “X, Y, Z” by two techniques, real time kinematic “RTK” and virtual reference system “VRS”. The accuracy of the applied method is tested on topographic survey project in Switzerland. The surveyed data of the specified project were collected by amateur digital camera Canon 18.2 MP, 182 captured images from approximately 85 m flight height, 18 Ground Check Point “GCP” determined by static GNSS. Horizontal accuracy is 0.029 m for VRS case, 0.034 m for RTK case and vertical accuracy is 0.026 m for VRS case, 0.029 for RTK case.

Performance evaluation of non‐metric digital camera for photogrammetric application

Abstract During the last year amateur low‐cost digital cameras are increasingly expected to contribute to the digital photogrammetry. An important aspect of the suitability of these cameras is determination of their geometrical instability. In order to evaluate amateur digital camera performance, small format, low resolution and low‐cost CCD camera have been investigated in two considerations: determining inner orientation parameters at different time and estimating accuracy in test field experiments. The calibration results demonstrate the poor stability of such a digital camera. As a result of the instability, amateur cameras have limited possibilities in close‐range photogrammetry. However, the investigated camera under certain limited accuracy requirements can be used for low‐accuracy photogrammetric application.

PERFORMANCE EVALUATION OF NON-METRIC DIGITAL CAMERA FOR PHOTOGRAMMETRIC APPLICATION

During the last year amateur low‐cost digital cameras are increasingly expected to contribute to the digital photogrammetry. An important aspect of the suitability of these cameras is determination of their geometrical instability. In order to evaluate amateur digital camera performance, small format, low resolution and low-cost CCD camera have been investigated in two considerations: determining inner orientation parameters at different time and estimating accuracy in test field experiments. The calibration results demonstrate the poor stability of such a digital camera. As a result of the instability, amateur cameras have limited possibilities in close-range photogrammetry. However, the investigated camera under certain limited accuracy requirements can be used for low-accuracy photogrammetric application.

New tools for rock art modelling: automated sensor integration in Pindal Cave

This paper presents the integration of automated sensors based on a terrestrial laser scanner and an amateur digital camera with the aim of generating a photorealistic three-dimensional (3D) model of the Principal Panel in Pindal Cave (Spain). The approach developed for 3D modelling overcomes many of the problems related to the independent implementation of photogrammetry and laser scanning. Particularly, a sequential and hierarchical approach was developed based on the processing and matching of images from the camera (camera image) and the laser scanner (range image). The results obtained demonstrate that the workflow for this model is automatic, effective, and accurate. The presented approach was found to create hyper-realistic models, even improving upon human visual capabilities.

CO-REGISTRATION OF PHOTOGRAMMETRIC AND LIDAR DATA: METHODOLOGY AND CASE STUDY

Registration activities combine data from different sources in order to attain higher accuracy and derive more information than available from one source. The increasing availability of a wide variety of sensors capable of capturing high quality and complementary data requires parallel efforts for developing accurate and robust registration techniques. Currently, photogrammetric and LIDAR systems are being incorporated in a wide spectrum of mapping applications such as city modeling, surface reconstruction, and object recognition. Photogrammetric processing of overlapping imagery provides accurate information regarding object space break-lines in addition to an explicit semantic description of the photographed objects. On the other hand, LIDAR systems supply dense geometric surface information in the form of non-selective points. Considering the properties of photogrammetric and LIDAR data, it is clear that the two technologies provide complementary information. However, the synergic characteristics of both systems can be fully utilized only after successful registration of the photogrammetric and LIDAR data relative to a common reference frame. The registration methodology has to deal with three issues: registration primitives, transformation function, and similarity measure. This paper presents two methodologies for utilizing straight-line features derived from both datasets as the registration primitives. The first methodology directly incorporates the LIDAR lines as control information in the photogrammetric triangulation. The second methodology starts by generating a photogrammetric model relative to an arbitrary datum. Then, LIDAR features are used as control information for the absolute orientation of the photogrammetric model. In addition to the registration methodologies, the paper presents a comparative analysis between two approaches for extracting linear features from raw and processed/interpolated LIDAR data. Also, a comparative analysis between metric analog and amateur digital cameras within the registration process will be presented. The performance analysis is based on the quality of fit of the final alignment between the LIDAR and photogrammetric models.

An automatic procedure for co-registration of terrestrial laser scanners and digital cameras

Driven by progress in sensor technology, algorithms and data processing capabilities, close range photogrammetry has found a wide range of new application fields over the past two decades. Particularly, the emergence of terrestrial laser scanner has contributed to the close range photogrammetry “popularization” through many promising new applications. Nevertheless, a central issue in many of these developments is the integration of sensor technology with reliable data processing schemes to generate highly automated photogrammetric measurements systems. This paper presents a flexible approach for the automatic co-registration of terrestrial laser scanners (TLS) and amateur digital cameras (DC) to be used effectively in practice. Particularly, the developed approach deals with two different images: a camera image acquired with a DC and a range image obtained with a TLS. To this end, an open-source tool “USAlign” has been developed for testing the different experiments.

デジタルスチルカメラのキャリブレーションにおける最適状況の検討

デジタルスチルカメラのキャリブレーションにおける最適状況の検討

Stability and Reproducibility of an Amateur Digital Camera for Dental Photography

Digital photography has become more technologically sophisticated and increasingly affordable in recent years. Digital imaging plus color analysis software editing by non-professional photographers has been widely used in color matching, bleaching evaluation, teaching, and fabrication of prostheses, While the typical commercially available digital camera produces satisfactory results for everyday needs, generally only sophisticated photographic equipment operated by trained photographers is suitable for intraoral photography. In this study, we evaluated the reproducibility and stability of a widely available amateur digital camera in an extraoral situation with a constant light source (D65) and in an intraoral situation using various light sources (D65 a ring flash), The extraoral photographic results showed a highly effective database of clinical pictures compiled even with the amateur digital camera. However, the intraoral experiment showed that the different light sources had significantly different effects on the results, We suggest that the extraoral photographic method we used in this study has good color stability and exceptional reproducibility. However, for intraoral photography, different light sources can produce different effects on the values or brightness of the image.

斜距離を制約条件とした複合型画像計測システムにおけるカメラキャリブレーションの開発に関する研究

A convenient 3D measurement using amateur digital cameras is enormously expected in various fields with appearance of the low coat and high-resolution amateur digital cameras. In these circumstances, software for digital photogrammetry “3DiVision” was designed to perform convenient 3D measurement using amateur digital cameras. However, there are still problems for efficient digital photogrammetry. These problems include distance measurement for absolute orientation and interior orientation which should be performed beforehand, and these restrictions should be removed for ideal convenient photogrammetry using amateur digital cameras.With this objective, Image Based Integrated Measurement (IBIM) System which consists of mirrors, amateur digital camera, and laser range finder was developed by the authors. The most remarkable point of the system is its ability to calculate both of exterior and interior orientation parameters without scale distance or Ground Control Points which have exact 3D coordinates in object field. This paper describes a camera calibration method for the IBIM System by using the distances from center of the digital camera to object field and evaluation of this camera calibration method.

民生用デジタルスチルカメラによるデジタル写真測量システム“３ＤｉＶｉｓｉｏｎ”の構築

Recently, the number of pixels of amateur digital cameras is amazingly increasing by modern semiconductor and digital technology. Nevertheless the highest pixel of amateur digital camera was 0.8 mega pixels in the 1996, 5.24 mega pixels was achieved in the 2001 and 3 mega pixels amateur digital cameras became the most popular camera on the market in Japan. In these circumstances, it is expected that the high resolution amateur digital cameras will become useful tool in various photogrammetric fields.With this objective, the authors have been concentrating on developing a low-cost photogrammetric system using a digital amateur camera. This paper reports performance evaluation of 3 mega pixels amateur digital camera, a low-cost photogrammetric system, and the software“3DiVisoin”which was designed to perform convenient 3D measurements using amateur digital camera with key words: 3Dimension, Digital image and Visualization. Furthermore, 3D modeling of historical structure which was designated as important cultural assets using the 3DiVision was introduced.