Image Measurement Method Research Articles

A high-speed 3-D image measurement method

With the recent popularization of digital cameras and projectors, practical applications of three-dimensional (3-D) image measurements based on intensity-modulation pattern projection are eagerly anticipated. Such an approach would permit a projection pattern to contain more measurement data, allowing 3-D data to be calculated with greater accuracy. However, to achieve a high level of accuracy using this approach, it is essential that an ideal observation pattern image should be obtained with a certain minimum number of stripes and a certain intensity distribution. To satisfy these requirements, an intensity correction method with two observation pattern images has previously been used. It is difficult to measure a fast-moving object in such calculations because the correspondence relation of the measured object is not established between the two photographic images, and consequently the pattern intensity is not corrected accurately. This study proposes an image analysis method for correcting intensity using an image synthesis technique that extracts precise stripes from a single observation pattern image. This analysis method allows 3-D shape measurements to be performed from a single projection pattern and a single image capture.

G050076 旋回流方式マイクロバブル発生器における気泡微細化 : 渦流室径の影響

Swirl-type micro-bubble generator has an advantage over others in that it can generate micro-bubble easily under low supplied pressure. In order to make the device generating micro-bubbles under low supplied pressure, swirl-type micro-bubble generator was investigated by changing swirl chamber diameter. Therefore the performance of swirl-type micro-bubble generator was evaluated by measuring the diameter of generated bubbles by the image measurement method. Moreover the swirl velocity and radial velocity distribution around exit of swirl-type micro-bubble generator was measured. The area in which swirl-type micro-bubble generator generated bubbles was observed by high speed camera. It was clarified that the diameter of bubbles generated by swirl-type micro-bubble generator became small, the swirl and the radial velocity increased with swirl chamber diameter.

A REVIEW ON ARTERY WALL SEGMENTATION TECHNIQUES AND INTIMA-MEDIA THICKNESS MEASUREMENT FOR CAROTID ULTRASOUND IMAGES

Stroke and heart attack, which could be led by a kind of cerebrovascular and cardiovascular disease named as atherosclerosis, would seriously cause human morbidity and mortality. It is important for the early stage diagnosis and monitoring medical intervention of the atherosclerosis. Carotid stenosis is a classical atherosclerotic lesion with vessel wall narrowing down and accumulating plaques burden. The carotid artery of intima-media thickness (IMT) is a key indicator to the disease. With the development of computer assisted diagnosis technology, the imaging techniques, segmentation algorithms, measurement methods, and evaluation tools have made considerable progress. Ultrasound imaging, being real-time, economic, reliable, and safe, now seems to become a standard in vascular assessment methodology especially for the measurement of IMT. This review firstly attempts to discuss the clinical relevance of measurements in clinical practice at first, and then followed by the challenges that one has to face when approaching the segmentation of ultrasound images. Secondly, the commonly used methods for the IMT segmentation and measurement are presented. Thirdly, discussion and evaluation of different segmentation techniques are performed. An overview of summary and future perspectives is given finally.

OMERACT 10 Sharp Symposium: Important Findings in Examination of Imaging Methods for Measurement of Joint Damage in Rheumatoid Arthritis

The Sharp Symposium was held at the Outcome Measures in Rheumatology Clinical Trials 2010 meeting (OMERACT 10) in honor of the late John Sharp, consummate rheumatologist and researcher. The symposium focused on the status of current scoring methods in radiography, magnetic resonance imaging (MRI), and ultrasound (US) in rheumatoid arthritis (RA), as well as on the use of soluble and tissue biomarkers in RA, with the aim of updating recommendations regarding methods for enhanced detection, monitoring, and prediction of joint damage in clinical trials.

Associative Networks: A New Approach to Market Segmentation

This paper aims to expand the domain of brand image perception measurement by providing a method for eliciting brand associative networks and comparing it with traditional brand image measurement methods. This paper then argues that these networks may differ from one individual to another, depending on the cultural background and/or the experience with the brand. Accordingly, the authors introduce a methodology of clustering consumers with similar perceptions into distinct segments, which can be targeted differently. Using picture analysis and metaphor-based elicitation techniques, Lipton's Ice Tea brand associations are extracted and utilised as an input for the creation of 160 individual associative networks. These networks are first aggregated to measure the brand reputation and subsequently clustered into six segments. This paper provides clear arguments for using associative networks as the preferred method to capture the complete brand image. The paper discusses implications of perceptual segmentation for image management, brand positioning, perceptual competition analysis and brand communication.

A Study on Design Preference for the Sales Spaces of Duty-Free Shops by the Examination of Image Evaluation - Cases of Duty-Free Shops in Jeju Special Self-governing Province -

The purpose of this study is to examine design preferences for the sales spaces of duty-free shops (DFSs) by conducting image evaluations. The results will help improve quality by influencing designs for the construction, extension or remodeling of these shops. An image measurement method, the semantic differential method, was used to measure cognitive structure using photos of shops. Photos were collected of the DFS at Jeju Island, as well as photos of brand stores designed by architects. Two sets of 16 photos (32 different photos in all) were selected according to photo classification standards and design concepts, both decided by reviewing previous studies and related materials. The evaluation and survey were done by two sets of subjects: sales employees, who have experience and special knowledge of the evaluation of sales space; and students majoring in architecture. To strengthen the evaluation results, I conducted a preliminary survey and a main survey, verifying and complementing findings. 116 surveys were conducted, of which 14 were of poor quality and rejected, leaving and 102 to be analyzed. The collected surveys were statistically analyzed, using SPSS 12.0 for Windows. Reliability, image profile, factor and multi-dimensional scaling analyses were conducted. As a result, image evaluation structure and characteristics were obtained for sales spaces of DFSs, confirming the difference between them and other spaces.

Studies on profile error and extruding aperture for the RP parts using the fused deposition modeling process

Fused deposition modeling (FDM) is one of the leading rapid prototyping processes for producing acrylonitrile butadiene styrene prototypes. However, the extruding accuracy in part fabrication is subject to transmission machinery and filament diameter. The parts cannot be filled up completely. Therefore, profile error and extruding apertures are two substantial quality characteristics to be considered. This study proposed an original image measurement method for examining profile error through a series of standard cylinders laid on the contour of the part. Also, images captured can be used to identify non-filled regions on part appearance to calculate aperture area on the surface layer. Besides, this study investigated the effects of extruding parameters, including contour width, contour depth, part raster width, and raster angle, on quality characteristics by Taguchi’s method. A thin solid model based on a 2-D spiral was designed to demonstrate the proposed approach. Results of ANOVA and confirmation experiments showed that the parametric criteria concluded in this study could obtain satisfactory performances on profile error and extruding apertures in the FDM process.

State of the art laryngeal imaging: research and clinical implications

This study provides a review of the latest advances in videostroboscopy, videokymography and high-speed videoendoscopy, and outlines the development of new laryngeal imaging modalities based on optical coherence tomography, laser-depth kymography, and magnetic resonance imaging (MRI), published in the past 2 years. Videostroboscopy and videokymography: Image quality has improved and several image processing and measurement techniques have been published. High-speed videoendoscopy: Significant progress has been made through increased sensitivity and frame rates of the cameras, and the development of facilitative playbacks, phonovibrography and several image segmentation and measurement methods. Clinical evidence was presented through applications in phonosurgery, comparisons with videostroboscopy, normative data, and better understanding of voice production. Optical coherence tomography: Latest developments allow the capture of dynamic high-resolution cross-sectional images of the vibrating vocal fold mucosa during phonation. Depth kymography: New laser technique allowing recording of the vertical movements of the vocal folds during phonation in calibrated spatial values. Laryngeal magnetic resonance: New methods allow high-resolution imaging of laryngeal tissue microstructure, or measuring of dynamic laryngeal structures during phonation. The endoscopic laryngeal imaging techniques have made significant advances increasing their clinical value, whereas techniques providing new types of potentially clinically relevant information have emerged.

Study on Application of Digital Image Measurement Method to Monitoring System for Tunnel Construction Management

This paper introduces a new measurement system using digital images for tunnel construction management. This measurement technique that utilizes digital images brings the following benefits compared with conventional techniques. The 3-dimensional deformations and the area-wide distributions of many measurement points can be obtained through simple measurement work. As the image data are all in digital format, real-time monitoring is possible. Measurement involves photographing from a distance only, eliminating the need for sophisticated techniques to improve accuracy as in conventional measurement. The necessary measurement hardware consists of a digital camera and a PC only, which brings down measurement cost. This study first attempts to establish the theoretical framework for using images photographed from any position with a digital camera for measuring any object for which is difficult to set fiducial points, such as a tunnel and reproduce the 3-dimensional displacement of a tunnel with considerable decision. It then goes on to clarify the relation between various measurement parameters and measurement decision and includes experiments to evaluate the performance of the technique that is applied to deformation measurement system of jointed rock masses. As a result, the establishment of a new measurement system featuring simple measurement work and a high degree of decision was found to be possible.

Quasi multi‐baseline‐stereo method with single camera for reducing occlusion

AbstractA robust 3D image measurement method is proposed in order to suppress occlusion by a quasi multi‐baseline‐stereo method based on a single camera configuration. There is no way to suppress completely the “occlusion problem” in the field of stereo geometry. In order to deal with this problem, the multi‐baseline‐stereo configuration is often adopted and is basically effective. This paper proposes a new configuration for stereo measurement by means of a single camera, a mechanical feeder for the object, image processing for the baseline calibration, and in particular, diagonal feeding of the object in front of the camera. The concept of this method is to realize a pair of stereo geometries in the stereo configuration with a single camera and a mechanical feeder. It is technically noted that the baseline of this single camera stereo was precisely calibrated by an image processing procedure in both the horizontal and vertical directions. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 93(1): 41–49, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10156

A practical 3D measurement system based on projection pattern control techniques

AbstractMost of the recent 3D image measurement methods have employed certain pattern projection techniques because of their higher reliabilities. Especially, the intensity‐modulated technique can detect more stripe addresses by a single projection and therefore is very much expected for its practical use in the near future. The traditional techniques of this type, however, have encountered several serious problems where 3D measurements are difficult in sensitivity, speed and accuracy or fatally impossible for unknown objects. In order to solve these problems, we propose an automatic control technique of angle and space frequency of projection pattern. Furthermore, for security of measurement accuracy and measurement speed, projection pattern intensity control technique and optimal intensity‐modulation projection technique are adopted in the proposal measurement system. By using the proposed technique the automatic 3D measurement intended for the geostationary objects and the swaying objects were realized in experimental results. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(11): 34–41, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10147

Practical image measurement of crack width for real concrete structure

AbstractCrack width is an important data item in inspection and diagnosis for the safety management of concrete structures. Usually the crack width measurement is performed manually by specialists using a crack scale. However, it takes a long time and lacks the objectivity needed for quantitative analysis. Therefore, the importance of image processing for visual inspection has been increasing in civil and construction engineering. Recently, many methods for crack width measurement have been proposed. We have already tried to measure crack width utilizing image processing. However, these methods have concentrated only on the application to test specimens. In this paper, we propose an improved image measurement method for crack width determination, intended for application to real concrete structures. In our method, a crack scale is applied to the concrete surface for image acquisition. The crack width is measured by the brightness of the crack scale areas on the image with sub‐pixel order accuracy. In the real world, the lighting conditions differ in various environments. To deal with such differences, this paper clarifies the conditions of effectiveness of our method for practical use. The validity of the proposed technique is investigated by experiments with images of a real concrete surface. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(10): 1–12, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10151

Automatic Image Measurement Technology in Endoscopy NDT

Endoscopy is an important non-destructive testing (NDT) method. It plays an important role in damage assessment and fault detection for aeroengine and structure [1,3]. However, the endoscopy usually relies on the operator’s experience to measure the defects manually in the application. Therefore, the current endoscopy method has some shortcomings that the accuracy and the efficiency of its measurement are low. To solve these problems, an automatic image measurement method based on the cubic spline interpolation is proposed in this paper. Firstly, the endoscopy image pre-processing such as gray processing, filtering, sharpening, segmentation and edge extraction are presented. Then, the pixel points in the processed edge image are handled by cubic spline interpolation and the spline function is got. After the starting point, vertex and endpoint of the defect are determined automatically, the width, depth and distance of defects are worked out. Finally, the method is applied in the fault detection for aeroengine’s blade. The experimental results show that this method can detect the width, depth and distance of the aeroengine’s blade defects exactly and quickly.

Basic Image Measurement for Laser Welding Robot Motion Control

Laser welding, provides high-density energy, is easy to control, and is low in heat input but deep in depth, enabling it to be used for small-area precision welding. However, Automating welding using robots has been considered, but laser welding requires accurate alignment and direction of irradiation because of its capability of sensitive welding. In this paper, basic image measurement method is proposed for Hand-Eye Laser Welding System equipped with an optical microscope and a CMOS camera, as follows. 1) A core line detection method of a slit laser image that has robustness against variation of observation direction and speckle patterns is proposed. 2) The parameter identification method of laser planes utilizing the core line detection method is proposed for measurement. 3) It is derived measurement equations of the position and the posture of the metal plate from geometric consideration utilizing the identified parameters and the core line detection.

Edge detection of steel plates at high temperature using image measurement

An edge detection method for the measurement of steel plate’s thermal expansion is proposed in this paper, where the shrinkage of a steel plate is measured when temperature drops. First, images are picked up by an imaging system; a method of regional edge detection based on grayscales’ sudden change is then applied to detect the edges of the steel plate; finally, pixel coordinates of the edge position are transformed to physical coordinates through calibration parameters. The experiment shows that the real-time, high precision, and non-contact measurement of the steel plate’s edge position under high temperature can be realized using the imaging measurement method established in this paper.

G202 旋回流式マイクロバブル発生器における流出口形状が気泡径に及ぼす影響(GS-2 キャビテーション・マイクロバブル・数値計算1,一般セッション)

The characteristics of the swirl-type micro bubble generation device were investigated by changing the inflow diameter, the exit angle, and inner pressure. The performance of the micro bubble generation device was evaluated by the bubble diameter which was measured by the image measurement method. When the micro bubbles were generated, it was confirmed that there were two kinds of generation forms. In one form, the nozzle exit flow discharges in radial direction, and the other form, the flow discharges in axial direction. In radial flow out type, the axial flow velocity was widely distributed at the exit of nozzle, and causing strong recirculation zone in the central portion. And it was proved that the micro bubble became minuter in this discharge form, and the relation between the bubble diameter and pressure changed irregularly.

Application of image processing to measure road distresses

Pavements usually experience different types of distresses due to repeated traffic loads, aggressive environmental conditions, construction materials, soil condition of the underline subgrade, and the method of construction. Longitudinal and transverse cracking, potholes, rutting, and bleeding are common examples of such distresses associated with flexible pavements. As time progresses, the severity of these distresses increases and consequently, ride quality is adversely affected. Early detection and measurement of the extent of distresses coupled with prompt reactive measures are necessary to keep the pavement function at an acceptable level. Traditional methods for distress detection and measurement are laborious, time consuming, and subject the involved personnel to accidents. In contrast, image measurement methods are effortless, safe, and can be performed in a short time. This research paper performs image processing measurements to estimate areas of a pothole and alligator cracking, and sets a program for plane measurements of an area that experience rutting. The image measurements are compared with the traditional measurements. The results show that image measurements are close to those obtained by using the traditional methods.

Correlated biofilm imaging, transport and metabolism measurements via combined nuclear magnetic resonance and confocal microscopy

Bacterial biofilms are complex, three-dimensional communities found nearly everywhere in nature and are also associated with many human diseases. Detailed metabolic information is critical to understand and exploit beneficial biofilms as well as combat antibiotic-resistant, disease-associated forms. However, most current techniques used to measure temporal and spatial metabolite profiles in these delicate structures are invasive or destructive. Here, we describe imaging, transport and metabolite measurement methods and their correlation for live, non-invasive monitoring of biofilm processes. This novel combination of measurements is enabled by the use of an integrated nuclear magnetic resonance (NMR) and confocal laser scanning microscope (CLSM). NMR methods provide macroscopic structure, metabolic pathway and rate data, spatially resolved metabolite concentrations and water diffusion profiles within the biofilm. In particular, current depth-resolved spectroscopy methods are applied to detect metabolites in 140-190 nl volumes within biofilms of the dissimilatory metal-reducing bacterium Shewanella oneidensis strain MR-1 and the oral bacterium implicated in caries disease, Streptococcus mutans strain UA159. The perfused sample chamber also contains a transparent optical window allowing for the collection of complementary fluorescence information using a unique, in-magnet CLSM. In this example, the entire three-dimensional biofilm structure was imaged using magnetic resonance imaging. This was then correlated to a fluorescent CLSM image by employing a green fluorescent protein reporter construct of S. oneidensis. Non-invasive techniques such as described here, which enable measurements of dynamic metabolic processes, especially in a depth-resolved fashion, are expected to advance our understanding of processes occurring within biofilm communities.

Practical 3-D Measurement System based on Projection Pattern Control Techniques

Most of the recent 3-D image measurement methods have employed certain pattern projection techniques because of their higher reliabilities. Especially, the intensity-modulated technique can detect more stripe addresses by a single projection and therefore is very much expected for its practical use in near future. The traditional techniques of this type, however, have encountered several serious problems where 3-D measurements are difficult in sensitivity, speed and accuracy or fatally impossible for unknown objects. In order to solve the this problems, we propose an automatic control technique of angle and space frequency of projection pattern. Furthermore, for secure of measurement accuracy and measurement speed, projection pattern intensity control technique and optimal intensity-modulation projection technique are adopted in the proposal measurement system. By using proposed technique the automatic 3-D measurement intended for the geostationary objects and the swaying objects were realized in experimental results.

Practical Image Measurement of Crack Width for Real Concrete Structure

Crack width is an important data in the inspection and diagnosis for the safety management of concrete structures. Usually the crack width measurement is done manually by specialists using crack scale. However, it takes a long time and lacks the objectivity for quantitative analysis. Therefore, the importance of image processing for visual inspection has been increasing in civil and construction engineering. Recently, many methods for the crack width measurement have been proposed. We have already tried to measure crack width utilizing image processing. However, these methods concentrated only on the application to test specimens. In this paper, we proposes an improved image measurement method of crack width for the application to real concrete structures. Our method attached crack scale on the concrete surface in the image acquisition. Crack width is measured by the brightness of crack scale areas on the image with sub-pixel order accuracy. In the real world, the lighting condition is different in various environments. For its difference, this paper clarifies the efficient condition of our method for the practical use. The validity of the proposed technique is investigated through experiments with images of a real concrete surface.