Photographic Measurements Research Articles

Robust sub-micrometer displacement measurement using dual wavelength speckle correlation.

The unique characteristics of speckle correlation techniques including simple setup and fast, non-contact, high resolution measurement capability offer great potential for industrial applications. Robustness is an important requirement for industrial applications, which limits the application of many common techniques such as interferometric or photographic measurements, especially in mechanical workshops. This paper introduces an innovative technique for displacement measurement using speckle photography that is robust to disturbances, imaging errors, and does not require a large number of database patterns for calibration. It uses the relative correlation of the speckle patterns generated by two parallel, overlapping laser beams with an identical spot size and different wavelengths for relative displacement measurement in sub-micrometer order, and requires only one reference pattern that is updated frequently during the measurement process. The method is demonstrated over 200 µm range and is extendable to longer ranges.

STRENGTH AND FRACTURE CHARACTERISTIC OF ROCK MASS CONTAINING PARALLEL FISSURES

In order to investigate the strength characteristic and crack extension law of rock mass containing parallel fissures, uniaxial compression tests of rock-like samples with different fissure angles were conducted combined with the digital photography measurement system. The results show that the degradation of peak strength and elastic modulus of samples is about 10.84%~35.62% and 9.79%~54.17% respectively with the effect of preset fissures. With the increase of the fissure angle, the peak strength of samples decreases first and then increases, forming a typical characteristic of “U” type, and it reaches the minimum value as θ is 45°. The failure form is closely related to the fissure angle. The extending types of secondary cracks are mainly inclined cracks and central cracks when the joint angle is 15° or 30°, and the final instability fracture mode is due to the inclined cracks. However, when the joint angle is 45°, 60° or 75°, the extending types of secondary cracks are mainly wing cracks and coplanar cracks, and the final instability fracture mode mainly depends on the coplanar cracks.

3D RECONSTRUCTION OF CULTURAL TOURISM ATTRACTIONS FROM INDOOR TO OUTDOOR BASED ON PORTABLE FOUR-CAMERA STEREO VISION SYSTEM

Abstract. Building the fine 3D model from outdoor to indoor is becoming a necessity for protecting the cultural tourism resources. However, the existing 3D modelling technologies mainly focus on outdoor areas. Actually, a 3D model should contain detailed descriptions of both its appearance and its internal structure, including architectural components. In this paper, a portable four-camera stereo photographic measurement system is developed, which can provide a professional solution for fast 3D data acquisition, processing, integration, reconstruction and visualization. Given a specific scene or object, it can directly collect physical geometric information such as positions, sizes and shapes of an object or a scene, as well as physical property information such as the materials and textures. On the basis of the information, 3D model can be automatically constructed. The system has been applied to the indooroutdoor seamless modelling of distinctive architecture existing in two typical cultural tourism zones, that is, Tibetan and Qiang ethnic minority villages in Sichuan Jiuzhaigou Scenic Area and Tujia ethnic minority villages in Hubei Shennongjia Nature Reserve, providing a new method and platform for protection of minority cultural characteristics, 3D reconstruction and cultural tourism.

AN AUTOMATIC 3D RECONSTRUCTION METHOD BASED ON MULTI-VIEW STEREO VISION FOR THE MOGAO GROTTOES

Abstract. This paper presents an automatic three-dimensional reconstruction method based on multi-view stereo vision for the Mogao Grottoes. 3D digitization technique has been used in cultural heritage conservation and replication over the past decade, especially the methods based on binocular stereo vision. However, mismatched points are inevitable in traditional binocular stereo matching due to repeatable or similar features of binocular images. In order to reduce the probability of mismatching greatly and improve the measure precision, a portable four-camera photographic measurement system is used for 3D modelling of a scene. Four cameras of the measurement system form six binocular systems with baselines of different lengths to add extra matching constraints and offer multiple measurements. Matching error based on epipolar constraint is introduced to remove the mismatched points. Finally, an accurate point cloud can be generated by multi-images matching and sub-pixel interpolation. Delaunay triangulation and texture mapping are performed to obtain the 3D model of a scene. The method has been tested on 3D reconstruction several scenes of the Mogao Grottoes and good results verify the effectiveness of the method.

A portable mirror stand for clinical facial photo documentation.

In plastic surgery, patient photography is a vital component of clinical, educational, legal, and research documentation. Optimal acquisition of photographic data requires a dedicated photography studio or a three-dimensional anatomic scanner, both of which are financially impractical for most clinicians. Simplified photo standardization is proposed for use in random clinical settings by using a portable device called the Mirror Stand (MirS). This model device aims to mimic a studio environment by incorporating the basic elements of producing consistent photographs. The pilot MirS is designed for facial photography. Images of 40 random subjects were obtained using the MirS with three different cameras. Real anthropometric measurements of each subject were collected, compared with the photographic measurements, and analyzed. In this study, all three cameras produced equally reliable measurements. Actual facial measurements were comparable to the photogrammetric measurements obtained from photographs taken using the MirS. A constant formula was derived; it allowed the conversion of photographic values into real anthropometric values. The MirS produced consistent photographs with respect to the measurements. The photographs obtained could be translated reliably into their real anthropometric measurements. Therefore, the MirS can be applied in daily practice, providing an efficient alternative for obtaining a standard justifiable photograph.

Repeatability and comparison of clinical tests in children with spastic diplegia and with typical development,

Objective The aims of this study were to evaluate the reliability of three range of motion tests (Straight Leg Raise, Modified Thomas, and Duncan-Ely) using photographic measurements in children with spastic diplegic cerebral palsy (SD) and with typical development (TD). Methods A cross-sectional test-retest design was applied to compare muscle-tendon unit shortening tests between groups. Results The tests showed reliability that ranged from good to excellent (ICC > 0.8), except for the Thomas Test for the bi-articular hip flexor muscle-tendon unit of the TD group (ICC = 0.7). Differences between groups were found in all tests (p < 0.05), except when the range of motion of the bi-articular hip flexor muscles was assessed using the Thomas test (p > 0.05). Conclusion Children with SD presents a smaller range of motion than the TD group. However, the Thomas Test for the bi-articular hip flexor muscles was unable to determine differences between children with spastic diplegic cerebral palsy from that with typical development.

Photographic Assessment of Upper Back Postures in Computer Users: A Validity Study

Computers are firmly established as a part of everyday life for both, adults and children, in many countries as a part of ergonomics. However, prolonged static sitting is accompanied by discomfort and musculoskeletal complications due to sustained immobility. Objective of study: To test the validity of sitting postures using photographs in upright, neutral and slumped posture in computer users and justify which posture should be adopted by computer users. Need of study: There are various ways to measure the postural alterations in upper back using various equipment's like goniometers, flexi ruler, inclinometer, radiographs. By this study we need to study the alterations in upper back posture using photographic measures and calculating the upper back angles using AutoCAD software. Inclusion criteria: Both gender between 18-35years with Right hand dominance and Undertaking computer or computype study for minimal 20hours/week were included. Exclusion criteria: subject with musculoskeletal disorders in neck or upper extremity, traumatic or post-traumatic conditions, who compromise their ability to assume normal, upright or slumped position on the day of data collection and with Left hand dominance were excluded. Materials used: markers, desktop computer unit with a mouse pad, desk, chair, stop watch, recording sheet, plinth/table with books, Sony Digital camera(14.1 megapixel), AutoCAD software 32bits Methodology: A cross sectional observational study was done on 60 computer users(20/group)and were asked to play game on the computer which was a 30 min task. The pre and post NDI was assessed and sagittal head angle, cervical angle, protraction/retraction angle, thoracic angle and arm angle were assessed using AutoCAD software. Results: on the basis of intergroup comparison it was found that slumped posture showed more changes as compared to upright and neutral; while the intragroup comparison data on two-tailed ANOVA scale stated that cervical angle had maximum and protraction/retraction angle showed minimal variability (7.07–54.16)

Automated 3D Scenes Reconstruction Using Multiple Stereo Pairs from Portable Four-Camera Photographic Measurement System

An effective automatic 3D reconstruction method using a portable four-camera photographic measurement system (PFCPMS) is proposed. By taking advantage of the complementary stereo information from four cameras, a fast and highly accurate feature point matching algorithm is developed for 3D reconstruction. Specifically, we first utilize a projection method to obtain a large number of dense feature points. And then a reduction and clustering treatment is applied to simplify the Delaunay triangulation process and reconstruct a 3D model for each scene. In addition, a 3D model stitching approach is proposed to further improve the performance of the limited field-of-view for image-based method. The experimental results tested on the 172 cave in Mogao Grottoes indicate that the proposed method is effective to reconstruct a 3D scene with a low-cost four-camera photographic measurement system.

Reliability and validity study of measurements on digital photography to evaluate shoulder balance in idiopathic scoliosis.

ObjectiveTo determine the validity of digital photography as an evaluation method for shoulder balance (ShB) in patients with idiopathic scoliosis.Material and methodsA total of 80 patients were included (mean age 20.3 years; 85% women). We obtained a full x-ray of the vertebral column and front and back clinical photography for all patients. For antero-posterior x-rays we measured the proximal thoracic curve angles (CPT). To evaluate radiological shoulder balance we calculated the clavicle-rib intersection angle (CRIA) and T1-tilt. For clinical photography we measured shoulder height angle (SHA), axilla height angle (AHA) and the left right trapezium angle (LRTA). We analyzed the reliability of the different photographic measurements and the correlation between these and the radiological parameters.ResultsThe mean magnitude of PTC, CRIA and T1-tilt were 19°, −0.6° and 1.4° respectively. Mean SHA from the front was −1.7°. All photographic measurements revealed an excellent-near perfect intra and inter-observer reliability in both photographic projections. No correlation was found between the ShB and the magnitude of the PTC. A statistically significant correlation was found between clinical balance of the shoulders and radiological balance (r between 0.37 and 0.51).ConclusionsDigital clinical photography appears to be a reliable method for objective clinical measurement of ShB. The correlation between clinical and radiological balance is statistically significant although moderate/weak.Electronic supplementary materialThe online version of this article (doi:10.1186/s13013-014-0023-6) contains supplementary material, which is available to authorized users.

Radiographic, ultrasonographic, and anatomic assessment of femoral trochlea morphology in red foxes (Vulpes vulpes).

To compare repeatability and equivalency of measures of femoral trochlea depth and trochlear angle in red foxes (Vulpes vulpes) determined by use of radiography, ultrasonography, and digital photography of cadaver limbs. 24 pelvic limbs from 12 red fox cadavers. Cranioproximal-craniodistal oblique (skyline) and lateromedial radiographic views of the stifle joint and ultrasonographic images at 5 locations along the femoral trochlea were used in the study. Spacing of the 5 locations was determined on the basis of patellar position with the stifle joint at various caudal angles ranging from 96° to maximal extension (approx 170°). Ultrasonographic measurements were compared with those obtained at matched locations on photographs of anatomic preparations. Trochlear depth was assessed with all 3 image formats, and trochlear angle (measured between the trochlear ridges and sulcus) was assessed on radiographs and ultrasonographic images. Patellar thickness was measured on radiographs. Values obtained were compared by means of ANOVA, modified Bland-Altman plots, and repeatability testing. Depth measurement repeatability was considered good for all modalities. Small but significant differences between mean ultrasonographic trochlear depth and anatomic (photographic) measurements were found at 3 locations; 95% limits of agreement for paired anatomic and ultrasonographic measurements were wide. The ratio of trochlear depth to radiographic patellar thickness was approximately 30% for all modalities. Trochlear angle measurements were more variable than trochlear depth measurements, especially in the distal aspect of the trochlea. Paired anatomic and ultrasonographic measurements did not appear equivalent in this study, possibly attributable to imprecise probe location, which could limit quantitative use of ultrasonography in assessing proximal trochlear depth in a clinical setting.

Correlation analysis between digital photography measurement of trunk deformity and self-image perception in patients with idiopathic scoliosis

Trunk deformity in idiopathic scoliosis has been fully analyzed using different surface metrics but all of them are expensive and cannot be widely used. Recently it has been suggested that some measures of trunk deformity obtained in digital photography can be useful in the assessment of trunk deformity. Some asymmetry measures have been proposed but the relationship between these measures and patients’ self-image perception has not been established.

Intrarater and Interrater Reliability of Photographic Measurement of Upper-Body Standing Posture of Adolescents

ObjectiveThe purposes of this study were to determine the intrarater and interrater reliability of a photographic measurement of the sagittal postures of the cervical spine and shoulder, quantitatively characterize the postural alignment of the head and shoulders in the sagittal plane of Portuguese adolescents 15 to 17 years old in natural erect standing, and analyze differences in postural angles between sexes. MethodsThis cross-sectional study was conducted in 2 secondary schools in Portugal where 275 adolescent students (146 females and 129 males) aged 15 to 17 years were evaluated. Sagittal head, cervical, and shoulder angles were measured with photogrammetry and the Postural Assessment Software. ResultsFor interrater reliability, all of the intraclass correlation coefficient (ICC) values for the 3 angles were higher than 0.85. For intrarater reliability, the ICC values for the sagittal head angle, shoulder angle, and cervical angle were 0.83, 0.78, and 0.66, respectively. Mean values of sagittal head, cervical, and shoulder angles were 17.2° ± 5.7°, 47.4° ± 5.2°, and 51.4° ± 8.5°, respectively. Anterior head carriage was demonstrated by 68% of the adolescents, whereas 58% had protraction of the shoulder(s). Males had significantly higher mean cervical and sagittal head angles. ConclusionsForward head posture and protracted shoulders were common postural disorders in adolescents 15 to 17 years old, with females revealing a lower mean cervical angle. The intrarater and interrater evaluation of standing sagittal posture of the cervical spine and shoulders by photogrammetry was reliable.

Objective breast volume, shape and surface area assessment: a systematic review of breast measurement methods.

There are many methods of measuring the breast and their clinical applications are well described in the literature. However, there has been no attempt to compare these various methods to allow the user to have a broad overview of the subject. The authors have attempted to summarise all the available methods to measure the breast in this article to provide a useful reference for all. A comprehensive literature search of PubMed was performed, and the resulting articles were screened and reviewed. The data regarding the methods' mechanism, reliability, time and cost were evaluated and compared. A total of 74 articles dating from 1970 to 2013 were included in this study. All of the methods can be classified into those that measure (1) volume, (2) shape and (3) surface area. Each category consists of several methods that work through different mechanisms and they vary in their reliability and feasibility. Based on their mechanism, the volume measurement methods were further grouped into the natural shape methods, the stereological method, the geometrical methods and the mathematical modelling method. More objective breast evaluation can be achieved if all three dimensions (volume, shape and surface area) are considered. In the volume measurements, 3D modelling and the MRI are the most reliable tools. Linear measurement (geometry) and mathematical modelling are less accurate but are more economical. In the shape measurements, besides the traditional linear measurement, 3D methods that can deliver colour-coded maps and Swanson's 2D photographic measurement system are capable of depicting and tracking breast shape changes after surgery. Although the surface area metric has not been used extensively, it has potential in clinical and research applications. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Botulinum toxin to improve results in cleft lip repair.

Upper lip wounds that lie perpendicular to the relaxed skin tension lines are subjected to repetitive dynamic tension caused by the orbicularis oris muscle and are susceptible to unsatisfactory scarring. In this double-blind, randomized, vehicle-controlled, prospective trial, 60 consecutive patients with unilateral cleft lip undergoing primary cheiloplasties between August of 2011 and June of 2012 were randomized to receive botulinum toxin type A or vehicle injections into the subjacent orbicularis oris muscle immediately after wound closure. Scars were assessed after 6 months using the Vancouver Scar Scale, photographic visual analogue scale, and photographic scar width measurements. Fifty-nine patients completed the trial. Measurements of scar widths at two defined points revealed significantly better visual analogue scale scores and narrower scars in the experimental group. However, Vancouver Scar Scale assessments were similar between groups. Botulinum toxin injections into the subjacent orbicularis oris muscle produced better appearing and narrower cheiloplasty scars, but provided no additional benefits in terms of scar pigmentation, vascularity, pliability, or height. Therapeutic, II.

No. 267 Correlation Analysis Between Digital Photography Measurement of Trunk Deformity and Self-Image Perception in Patients With Idiopathic Scoliosis

No. 267 Correlation Analysis Between Digital Photography Measurement of Trunk Deformity and Self-Image Perception in Patients With Idiopathic Scoliosis

Comparison of Drop Size and Velocity Measurements by a Laser PrecipitationMeter and Low-Speed Photographyor an Agriculture Sprinkler

<abstract> <bold><sc>Abstract. </sc></bold>Kinetic energy of water droplets has a substantial effect on development of a soil surface seal and infiltration rate of bare soil. Methods for measuring sprinkler droplet size and velocity needed to calculate droplet kinetic energy have been developed and tested over the past 50 years, each with advantages, disadvantages, and limitations. Drop size and velocity of an impact sprinkler at three operating pressures and one nozzle size were measured using a laser precipitation meter and compared with published values obtained using a photographic method. Significant differences in cumulative volume drop size distributions derived from the two measurement methods were found, especially at the highest operating pressure. Significant differences in droplet velocities were found between measurement methods as well. Significant differences were attributed to differences in minimum drop sizes measured; 0.5 mm for the photographic method versus 0.2 mm for the laser precipitation meter. The laser precipitation meter provided smaller cumulative volume drop size distributions compared to the photographic measurement method. The laser precipitation meter tended to provide greater drop velocities which were attributed to altitude differences at experimental sites. The difference in calculated droplet kinetic energy per unit drop volume based on drop and size velocity data from the laser precipitation meter and the photographic method ranged from +12.5 to -28%. The laser precipitation meter generally provided a lower estimate of sprinkler kinetic energy due to the measurement of a greater proportion of smaller drop sizes. Either method can be used to obtain drop size and velocity sprinkler drops needed to calculate sprinkler kinetic energy. The laser precipitation meter requires less skill and labor to measure drop size and velocity.

Steady-state total diffuse reflectance with an exponential decaying source.

The increasing preclinical and clinical utilization of digital cameras for photographic measurements of tissue conditions motivates the study of reflectance measurements obtained with planar illumination. We examine herein a formula that models the total diffuse reflectance measured from a semi-infinite medium using an exponentially decaying source, assuming continuous plane wave epi-illumination. The model is validated with experimental reflectance measurements from tissue mimicking phantoms. The need for adjusting the blood absorption spectrum due to pigment packaging is discussed along with the potential applications of the proposed formulation.

New surgical technique for ventral penile curvature without circumcision.

To describe and report on our variant of penile corporoplasty, the ‘double-breasted’ corporoplasty, with penoscrotal and infrapubic access not requiring circumcision. The medicolegal aspects of treatment are also discussed. Between February 1995 and October 2012, double-breasted corporoplasty was performed in 93 patients with congenital ventral penile curvature. Preoperative assessment comprised RigiScan monitoring, prostaglandin E1 injection with photographic documentation and measurement of penile angulation, administration of the International Index of Erectile Function-5 (IIEF-5) questionnaire, and biothesiometry up until 5 years ago when it was substituted with the Genito Sensory Analyser for testing sensitivity. Dorsal infrapubic access was used in the patients with ventral curvature. After preparation and incision of Colles' fascia, the penis is degloved and double-breasted corporoplasty is performed at the site established at preoperative assessment. The tunica albuginea is prepared, an incision is made, and the cavernous tissue is isolated from the albuginea to obtain two flaps that are then overlaid and sutured asymmetrically with interrupted 2-0 polyglactin 910 (Vicryl®) sutures. After the free edge of the albuginea is sutured with a running polyglactin 910 suture, a non-absorbable monofilament and uncoated suture made of polypropylene (Premicron®) suture is placed at the point of maximum traction. Complete correction of penile curvature was achieved in 96% of patients; recurrence occurred in 4%. No major complications were reported, nor were there neurovascular lesions or change in erectile function. Palpable subcutaneous irregularities at the site of the corporoplasty, without functional or aesthetic impairment, were reported by 35% of patients. There was no change in the appearance of the penis as circumcision was not performed and the residual scar was barely noticeable as it was hidden in the infrapubic fold. The corporoplasty technique can adequately restore the patient's psychophysical integrity, making it, from a medicolegal perspective, one of the most reliable procedures in the surgical repair of penile curvature. This original technique is associated with low morbidity, a low recurrence rate and excellent aesthetic results. The results show that it is safe and effective. When indicated for the surgical treatment of penile curvature, the choice of the technique satisfies the criteria of diligence and prudence for the surgeon's conduct.

SPOT-VEGETATION GEOV1 biophysical parameters in semi-arid agro-ecosystems

The VEGETATION system, which has been delivering global observations of the surface on a daily basis since 1998, provides key information for regional to global climate, environmental and natural resource management applications. Just recently, VEGETATION-derived GEOV1 biophysical products (LAI, FAPAR, and FCOVER) became available for the scientific community and were evaluated in this study for semi-arid forests in the Dry Chaco ecoregion, Argentina. Indirect validation with the MODIS-derived biophysical products (MOD15A2) shows a very good temporal consistency between both products for the period 2000–2011, with a remarkably smooth behaviour of the GEOV1 products. A good relationship between both products was found in the regression analysis with an R2 of 0.826 and 0.724 for LAI and FAPAR, respectively. Using direct validation with digital hemispherical photography (DHP) and ceptometer ground measurements, a relatively small RMSE (RMSELAI ≈ 0.31 and RMSEFAPAR ≈ 0.11) was found. The novel PASTIS-57 technique, which can derive continuous plant area index (PAI) estimates from light transmittance measurements, shows a similar temporal profile to the GEOV1 LAI product with a relatively high but constant offset for the dry forest study sites and a nearly identical profile for the deforested site (R2 = 0.86). Overall, PASTIS-57, in combination with satellite-based observations, shows potentials in LAI/PAI research and ecosystem carbon studies in general, but more ground measurements taken over multiple growing seasons and vegetation types are required to confirm these findings.

The Relationship Among Foot Posture, Core and Lower Extremity Muscle Function, and Postural Stability

Identification of impaired balance as a risk factor for lower extremity injury regardless of injury history has led to subsequent investigation of variables that may adversely affect balance in healthy individuals. To investigate the relationship among core and lower extremity muscle function, foot posture, and balance. Descriptive laboratory study. Musculoskeletal injury biomechanics laboratory. A total of 108 individuals (40 men, 68 women; age = 22.8 ± 4.7 years, height = 168.5 ± 10.4 cm, mass = 69.9 ± 13.3 kg) participated in the study. Core endurance was assessed during 1 time-to-failure trial, and isometric hip and ankle strength were assessed using a handheld dynamometer and isokinetic dynamometer, respectively. Foot structure was quantified using the digital photographic measurement method. Single-limb-stance time to boundary was assessed using a force plate during an eyes-closed condition. Hierarchical multiple regression analyses were performed to predict balance using lower extremity strength, foot posture, and core endurance. Foot posture (β = -0.22, P = .03) and ankle-inversion strength (β = -0.29, P = .006) predicted mediolateral balance. Increasing arch posture and ankle-inversion strength were associated with decreased mediolateral single-limb-stance balance. Increasing arch height was associated with decreased mediolateral control of single-limb stance. The relationship between time to boundary and injury risk, however, has not been explored. Therefore, the relationship between increasing arch height and injury due to postural instability cannot be determined from this study. If authors of future prospective studies identify a relationship between decreased time to boundary and increased injury risk, foot structure may be an important variable to assess during preparticipation physical examinations. The relationship between increasing ankle-inversion strength and decreased balance may require additional study to further elucidate the relationship between ankle strength and balance.