The Experts below are selected from a list of 95940 Experts worldwide ranked by ideXlab platform
Anuar Ahmad - One of the best experts on this subject based on the ideXlab platform.
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CALIBRATION OF Digital Camera FOR MEDICAL PHOTOGRAMMETRY
2020Co-Authors: Anuar Ahmad, Halim Setan, Zulkepli Majid, Albert K. ChongAbstract:Today, there are several low cost softwares that are available in the market that could be used for Digital close range photogrammetry applications such as for medical photogrammetry. Most softwares could be used to calibrate Digital Camera or other sensors and produce accurate results. This paper discusses about the experience of calibrating a consumer Digital Camera using low cost Digital close range photogrammetric software. A test field was used to calibrate the Digital Cameras. Convergent images and retro-reflective targets were employed in the study. The process of photography and processing the photographs were carried out within short period of time. In this study, self-calibrating bundle adjustment embedded in the software was used to recover the Camera calibration parameters of the consumer Digital Camera. Subsequently, the consumer Digital Camera was used to capture the photographs of human face for medical photogrammetry application. Output of calibrating the Digital Cameras include exterior orientation parameters, Camera calibration parameters and the object space coordinates. The results showed that all the Camera calibration parameters could be recovered without any difficulties and could be used to capture photographs or data for medical photogrammetry applications. Also the results from this study suggest that consumer Digital Camera is potential to be used in many close range photogrammetric applications and when the budget is limited.
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Accuracy assessment of calibrating high resolution Digital Camera
2013 IEEE 9th International Colloquium on Signal Processing and its Applications, 2013Co-Authors: Nurul Farhah Abdul Hamid, Anuar Ahmad, Abd Manan Samad, Ismail Ma'arof, Khairil Afendy HashimAbstract:Today many photogrammetric works involved the use of Digital Cameras due to it's in low cost. Digital Camera has been used in many photogrammetric applications such as archaeology, architecture, accident investigation, cultural heritage and etc. Theoretically, most Digital Camera is known as non-metric Camera where the interior geometrical of Digital Camera is not stable, however, the optical quality is not acceptable. The need for Camera calibration has been fundamental requirement for obtaining accurate measurement since the inception of photogrammetry. This study deals with the acquisition and processing of different configuration of Digital Camera (convergent and generic network) which are position at different height versus different Digital Camera setup. The accuracy assessment was performed for two high resolution Digital Cameras which are Nikon D90 and Rollei D30metric5 Digital Cameras. The height of Digital Camera is setup at approximately 80cm and 100cm. Finally, this study evaluates the accuracy of the Camera calibration based on standard deviation of interior Camera calibration parameters. This study shows that high resolution Nikon D90 Digital Camera which is categorized as low cost could be used in photogrammetric application with good accuracy achievable.
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Calibration of high resolution Digital Camera using self-calibration bundle adjustment method
2011 IEEE 7th International Colloquium on Signal Processing and its Applications, 2011Co-Authors: Wani Sofia Udin, Anuar AhmadAbstract:Currently, the price of Digital Camera is decreasing and many users afford to purchase it. The Digital Camera can be used for many applications. The Digital Camera can also be used for accurate measurement such as determination of three dimensional (3D) coordinates, production of accurate measurement and generation of 3D model of objects. However, the Digital Camera need to be calibrated to obtain accurate results. The aim of this study is to calibrate the Digital Camera so that it could be used for accurate measurement. In this study, close range photogrammetric technique was used to calibrate three high resolution Digital Cameras. The Digital Cameras used comprise of Rollei D30, Nikon D60 SLR and compact Nikon Coolpix S560. The three Digital Cameras were used to acquire photographs of three different sizes of testfield that are equipped with retro-reflective targets. The approximate 3D coordinates of the different testfield were estimated by measuring it manually. The three Digital Cameras were calibrated using self-calibration bundle adjustment method. The photographs of the testfield were acquired using potrait and landscape setup for each Camera location in 3D space. After the acquisition of the photographs of the testfield, they were downloaded into the computer for the measurement process of the retro-reflective targets and subsequently the final 3D coordinates of the retro-reflective targets were determined using the self-calibration bundle adjustment method. The coordinates of the retro-reflective targets were also determined using intersection method of total station which were used as referenced value. The 3D coordinates from the Digital Camera were then compared with the 3D coordinates of the total station. Results showed that the Nikon D60 SLR Digital Camera is superior than the other two Digital Cameras in term of accuracy and network precision. The next best result is shown by the Nikon Coolpix S560 compact Digital Camera and finally the Rollei D30. For the Rollei D30, the results are less accurate than the Nikon D60 SLR. However, the interior orientation parameters of this Camera are very stable. In conclusion, all the three high resolution Digital Cameras have the potential to be used for various close range applications.
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capability of low cost Digital Camera for production of orthophoto and volume determination
International Colloquium on Signal Processing and Its Applications, 2011Co-Authors: Khairul Nizam Tahar, Anuar AhmadAbstract:This paper discusses about the use of low cost Digital Camera or known as non metric Camera as photogrammetry tool for speeding up the process of acquiring aerial data. Digital Camera can also be categorized as non metric Camera. In photogrammetry, Digital Camera has been used for many diversified applications either in aerial photogrammetry or close range photogrammetry. The Digital Camera also has the potential to be used for landslide mapping and monitoring. In this study, a low cost Digital Camera has been used to acquire Digital images of a simulated model build from sand and cement (dimension of 1m × 3m) which represent some form of topographic surface. In the simulated model, an area was excavated to simulate landslide occur in the area. The acquired Digital images of the simulated model were then processed using photogrammetric technique to the final photogrammetric output that is the Digital orthophoto. The Digital Camera used is of high resolution and suitable for large scale mapping which does not involve large study area, require moderate accuracy and limited budget. The objective of this study is to investigate the capability of a low cost Digital Camera in generating three dimensional models, Digital elevation model (DEM) and finally the Digital orthophoto. The other objective of this study is to investigate whether the data captured using the Digital Camera can be used for volume determination that was excavated from an area in the simulated model. The results of the study showed that the low cost Digital Camera is capable of producing Digital orthophoto and capable of determining the excavated volume of the simulated model.
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Assessment of Digital Camera for mapping stream using close range photogrammetric technique
2010 6th International Colloquium on Signal Processing & its Applications, 2010Co-Authors: Abd Manan Samad, Anuar Ahmad, Natasha IshakAbstract:Photogrammetry is a technique that can be used for topographic mapping and many countries in the world used this technique for mapping. It also can be used for non-topographic mapping such as mapping facade of building, monument, historical building, human body and others using a technique known as close range photogrammetry. In this technique usually a metric Camera is used. However, with the advancement in Digital technology, it has embraces the technology where Digital Camera can be used for acquiring photograph of the object of interest. Usually the distance from the Camera to the object is within few centimetres and up to 300 meters. Today, there are many make and models of Digital Camera ranging from low cost to affordable cost. The cost of the Digital Camera is based on the technology used, resolution of the Digital image, capabilities and other factors. Due to the various make, model and capabilities the user of Digital Camera need to assess it if accurate measurement is required and produce output from the photogrammetric technique. In developed countries, Digital Camera (i.e in the form of metric and non-metric Camera) has been utilized together with close range photogrammetric technique for various applications and fields including mapping stream or river. The purpose of the study is to assess Digital Camera in mapping stream and determine the accuracy of measurement using close range photogrammetric technique. This study is divided into mapping stream model and real stream. The main output of this study is the orthophoto, The results showed that the computed root mean square error (RMSE) for the model stream is ±0.667m and ±0.619m using metric Camera and non-metric Camera respectively. While the computed RMSE for the real stream is ±0.444m and ±0.348m using metric Camera and non-metric Camera respectively. From this study, the results for the real stream are better than the stream model. Also the finding of this study demonstrates that both the metric Digital Camera and non-metric Digital Camera can be used for mapping stream.
Brian A Wandell - One of the best experts on this subject based on the ideXlab platform.
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Digital Camera simulation
Applied Optics, 2012Co-Authors: Joyce E. Farrell, Peter B Catrysse, Brian A WandellAbstract:We describe a simulation of the complete image processing pipeline of a Digital Camera, beginning with a radiometric description of the scene captured by the Camera and ending with a radiometric description of the image rendered on a display. We show that there is a good correspondence between measured and simulated sensor performance. Through the use of simulation, we can quantify the effects of individual Digital Camera components on system performance and image quality. This computational approach can be helpful for both Camera design and image quality assessment.
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Digital Camera simulation
Applied Optics, 2012Co-Authors: Joyce E. Farrell, Peter B Catrysse, Brian A WandellAbstract:We describe a simulation of the complete image processing pipeline of a Digital Camera, beginning with a radiometric description of the scene captured by the Camera and ending with a radiometric description of the image rendered on a display. We show that there is a good correspondence between measured and simulated sensor performance. Through the use of simulation, we can quantify the effects of individual Digital Camera components on system performance and image quality. This computational approach can be helpful for both Camera design and image quality assessment. © 2012 Optical Society of America.
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The Digital Camera is an Imaging System
Information Systems, 2010Co-Authors: Joyce E. Farrell, Peter B Catrysse, Brian A WandellAbstract:We describe methods for simulating the complete image processing pipeline of a Digital Camera, including the scene, optics, sensor, processing and display output.
Joyce E. Farrell - One of the best experts on this subject based on the ideXlab platform.
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Digital Camera simulation
Applied Optics, 2012Co-Authors: Joyce E. Farrell, Peter B Catrysse, Brian A WandellAbstract:We describe a simulation of the complete image processing pipeline of a Digital Camera, beginning with a radiometric description of the scene captured by the Camera and ending with a radiometric description of the image rendered on a display. We show that there is a good correspondence between measured and simulated sensor performance. Through the use of simulation, we can quantify the effects of individual Digital Camera components on system performance and image quality. This computational approach can be helpful for both Camera design and image quality assessment.
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Digital Camera simulation
Applied Optics, 2012Co-Authors: Joyce E. Farrell, Peter B Catrysse, Brian A WandellAbstract:We describe a simulation of the complete image processing pipeline of a Digital Camera, beginning with a radiometric description of the scene captured by the Camera and ending with a radiometric description of the image rendered on a display. We show that there is a good correspondence between measured and simulated sensor performance. Through the use of simulation, we can quantify the effects of individual Digital Camera components on system performance and image quality. This computational approach can be helpful for both Camera design and image quality assessment. © 2012 Optical Society of America.
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The Digital Camera is an Imaging System
Information Systems, 2010Co-Authors: Joyce E. Farrell, Peter B Catrysse, Brian A WandellAbstract:We describe methods for simulating the complete image processing pipeline of a Digital Camera, including the scene, optics, sensor, processing and display output.
Samo Simončič - One of the best experts on this subject based on the ideXlab platform.
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Temperature measurement during resistance spot welding using a Digital Camera
2013 IEEE International Conference on Mechatronics and Automation, 2013Co-Authors: Primož Podržaj, Samo SimončičAbstract:In this paper a novel approach for temperature measurement during resistance spot welding is presented. The temperature is calculated using the deformation of the electrode tip. The deformation is measured using a Digital Camera which acquires a sequence of images. These images are then compared and analyzed using a Digital correlation algorithm. The result is the deformation variation over time, which is then converted to temperature versus time. For a comparison a thermocouple was mounted on the same spot of the electrode tip. The comparison of both methods has confirmed the applicability of Digital Camera for temperature measurement.
Toadere Florin - One of the best experts on this subject based on the ideXlab platform.
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Color processing in a Digital Camera pipeline
Advanced Topics in Optoelectronics Microelectronics and Nanotechnologies IV, 2009Co-Authors: Toadere FlorinAbstract:The goal of this paper is to analyses the numerical color processing aspects, present in a Digital Camera pipeline. We simulate the colors transformation of an image that passes from the Bayer CFA (color filter array) to the XYZ color processing blocks; this part is know as numerical color processing pipeline. The analysis covers the part related to next color processing blocks: Bayer CFA, interpolation, color balancing, color correction, gamma correction and conversion from RGB to XYZ. The simulation results address the image quality and color processing part of a Digital Camera pipeline.
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Simulation of a Digital Camera Pipeline
2007 International Symposium on Signals Circuits and Systems, 2007Co-Authors: Toadere FlorinAbstract:The goal of this paper is to present an analysis of an image capture system and of the color process of an input image as it passes through the Digital Camera pipeline. The analysis covers only the part related to the optical sensor a Cook Tyler triplet, the optical part of the CCD (charge coupled devices) image sensor and color processing. We consider the image acquisition to be a LSI (linear shift invariant system) and axial, and the light propagation is orthogonal to system. The simulation results address the image acquisition and the processing part of a Digital Camera pipeline. The analysis can be useful to assist engineers in image quality evaluation and imaging system design.