Camera Filters Research Articles

Performance evaluation of a portable 3D vision coordinate measuring system

ABSTRACTIn this work, we present a portable 3D vision coordinate measuring machine (PCMM) for short range-real time photogrammetry. The PCMM performs 3D measurements of points using a single camera in combination with a hand tool and a computer. The hand tool has infrared LEDs serving as photogrammetric targets. The positions of these targets were pre-calibrated with an optical coordinate-measuring machine defining a local coordinate system on the hand tool. The camera has an infrared filter to exclude all ambient light but infrared targets. Positions of the imaged infrared targets are converted to 3D coordinates using pixel positions and pre-calibrated positions of the targets. Also, we present a set of criteria for selecting the infrared LEDs and the camera filter, a camera calibration method, a tracking and POSE algorithms, and a 3D coordinate error correction for the PCMM. The correction is performed using the PCMM as a range meter, which implies comparing the 3D coordinate points of the PCMM with a coordinate measuring machine, and then generating a look up table (LUT) for correction. The global error of the PCMM was evaluated under ASME B89.4.22-2004. Sphere and single point errors were around 1 mm, volumetric error were under 3 mm.

Lunar mare TiO2 abundances estimated from UV/Vis reflectance

The visible (400–700 nm) and near-infrared (700–2800 nm) reflectance of the lunar regolith is dominantly controlled by variations in the abundance of plagioclase, iron-bearing silicate minerals, opaque minerals (e.g., ilmenite), and maturation products (e.g., agglutinate glass, radiation-produced rims on soil grains, and Fe-metal). The same materials control reflectance into the near-UV (250–400 nm) with varying degrees of importance. A key difference is that while ilmenite is spectrally neutral in the visible to near-infrared, it exhibits a diagnostic upturn in reflectance in the near-UV, at wavelengths shorter than about 450 nm. The Lunar Reconnaissance Orbiter Wide Angle Camera (WAC) filters were specifically designed to take advantage of this spectral feature to enable more accurate mapping of ilmenite within mare soils than previously possible. Using the reflectance measured at 321 and 415 nm during 62 months of repeated near-global WAC observations, first we found a linear correlation between the TiO2 contents of the lunar soil samples and the 321/415 nm ratio of each sample return site. We then used the coefficients from the linear regression and the near-global WAC multispectral mosaic to derive a new TiO2 map. The average TiO2 content is 3.9 wt% for the 17 major maria. The highest TiO2 values were found in Mare Tranquillitatis (∼12.6 wt%) and Oceanus Procellarum (∼11.6 wt%). Regions contaminated by highland ejecta, lunar swirls, and the low-TiO2 maria (e.g., Mare Frigoris, the northeastern units of Mare Imbrium) exhibit very low TiO2 values (<2 wt%). We find that the Clementine visible to near-infrared based TiO2 maps (Lucey et al., 2000) have systematically higher values relative to the WAC estimates. The Lunar Prospector Gamma-Ray Spectrometer (GRS) TiO2 map is consistent with the WAC TiO2 map, although there are local offsets possibly due to the different depth sensitivities and large pixel scale of the GRS relative to the WAC. We find a wide variation of TiO2 abundances (from 0 to 10 wt%) for early mare volcanism (>2.6 Ga), whereas only medium to high TiO2 values (average = 6.8 wt%, minimum = 4.5 wt%) are found for younger mare units (<2.6 Ga).

Techniques Used to Establish the First Person Narrator and Perspective in Double Indemnity and Murder, My Sweet

Directed by Billy Wilder and Edward Dmytryk respectively, the films noir Double Indemnity (1944) and Murder, My Sweet (1944) each have a storyline that unfolds from a first person perspective as told by a narrator. The techniques used in the films establish this first person perspective through which the films are understood. Both films include voice over as a technique, which determines who the narrator is and the amount of information withheld or disclosed to the audience. Establishing the visual perspective of the narrator is portrayed through differently for each film. While, Double Indemnity utilizes camera angle, Murder, My Sweet uses camera filters and special effects. Lastly, to achieve the first person narration, the character narrating in each film must be present in every scene or give explanation of events that occur in his absence. The various techniques used in each film function cohesively to establish the narrator and achieve his perspective through which the plot is understood by the audience.

P1.08-049 CT Guided Labeling with Indocyanine Green of Small Lung Nodules for Sublobar Resection Utilizing Robotic Assisted Thorascopic Surgery (RATS)

Localization of deep and small pulmonary lung nodules undergoing a wedge or sublobar resection may be challenging during thoracoscopy, and may necessitate greater resection or conversion to thoracotomy. Particularly in robotic surgery, with the absence of tactile feedback. Percutaneous CT guided Indocyanine Green injection provides a means to pinpoint these nodules. A retrospective study of 40 consecutive patients who underwent preoperative CT-guided localization of solitary pulmonary nodules with ICG. Nodules ≤ 15mm were 21/40 (52.5%), ≤ 20mm 30/40 (75%), and ≤ 30mm 38/40 (95%). A 22-gauge spinal needle (BD, NJ) or Chiba needle (Cook, IA) was positioned into or adjacent to the nodule. 0.4cc Indocyanine Green was injected and the inner stylet withdrawn. The Xi daVinci robot (Intuitive Surgery, CA) was docked and the firefly filter of the 8mm camera was activated, and the nodule illuminates in a fluorescence green color. A wedge or sublobar resection was performed, with progression to lobectomy when indicated. CT guidance successfully localized the nodules in 100% of 40 patients employing this technique. Success was measured in nodule illumination as seen by the surgeon upon activation of the camera filter and confirmed on frozen and permanent section by pathology. Initial wedge resection for diagnosis prior to lobectomy and sublobar resection for decreased PFTs or decrease cardiac function were performed by Robotic Assisted Thoracoscopy (RATS). There were no conversions to thoracotomy. Diagnosis were adenocarcinoma in 18 patients (45%), squamous cell carcinoma in 7 patients (17.5%), carcinoid in 1 patient (2.5%), metastatic in 8 patients (20%), and benign in 6 patients (15%). There were no 30 or 90 day mortalities. A chest tube reinsertion in one patient for pneumothorax. Economically the cost for the vial of ICG is $79.56 compared to a fiducil marker at a cost of $128.00. Thoracic Surgery has access to CT scanners, without an extra cost, electromagnetic navigation systems come with significant added costs. Percutaneous CT guided labeling with ICG is quick and economical for the localization of small and deep nodules undergoing RATS wedge or sublobar resection. This technique may be supportive in preserving lung parenchyma and reduce the need for conversion to thoracotomy, maintaining minimal invasive thoracic surgery, especially where palpation or tactile feedback is absent.

Reflecting on a highly successful UEG Week 2016

With a comprehensive range of captivating new research and over 13,300 delegates in attendance, UEG Week 2016 in Vienna was a huge success in advancing the path of world-class digestive health research and is now recognised as one of Europe’s top five medical congresses. The Opening Plenary Session provided a superb overview of the most exciting developments in gastroenterology, endoscopy and hepatology in 2016, which included advancements in inflammatory bowel disease and coeliac disease, as well as highlights of the best scientific abstracts submitted to the congress. Among these abstracts included research outlining how gut microbial profiles could help to predict patient responsiveness to a low-FODMAP diet, offering new hope for irritable bowel syndrome sufferers. A new advancement in gastrointestinal cancer imaging was also presented during the Opening Plenary. The technique involves using a standard endoscopy system with a novel set of camera filters, increasing the number of colours that can be visualised during endoscopy from three to over 50. This approach, developing the capabilities of hyperspectral imaging, could help improve the ability to detect abnormal cells in the lining of the gut. One of the most popular topics during the week focused on non-coeliac gluten sensitivity. Here, amylase-trypsin inhibitors – a group of proteins found in wheat – were shown to activate an immune response in the gut that can then spread to other tissues in the body, such as the kidneys, spleen and brain, triggering the inflammation of chronic health conditions including multiple sclerosis, asthma and rheumatoid arthritis. Inflammatory bowel disease featured prominently at UEG Week 2016, including: a call for greater attention on, and funding for, paediatric IBD drug research and transition services; a one-day symposium on ‘Advances in Clinical Gastroenterology and Hepatology for Inflammatory Bowel Disease’ ; and the presentation of the eagerly-anticipated NOR-SWITCH study, demonstrating that a switch from INX to CT-P13 was not inferior to continued treatment with INX for patients with Crohn’s disease and ulcerative colitis. The NOR-SWITCH findings, presented during the most well-attended late-breaking abstract session at UEG Week, have the potential to significantly influence how medicines are used around the world. To read more highlights of UEG Week 2016 visit: https://www.ueg.eu/week/past-future/ueg-week-2016/

A robust butt welding seam finding technique for intelligent robotic welding system using active laser vision

Intelligent robotic welding requires automatic finding of the seam geometrical features in order for an efficient intelligent control. Performance of the system, therefore, heavily depends on the success of the seam finding stage. Among various seam finding techniques, active laser vision is the most effective approach. It typically requires high-quality lasers, camera and optical filters. The success of the algorithm is highly sensitive to the image processing and feature extraction algorithms. In this work, sequential image processing and feature extraction algorithms are proposed to effectively extract the seam geometrical properties from a low-quality laser image captured without the conventional narrow band filter. A novel method of laser segmentation and detection is proposed. The segmentation method involves averaging, colour processing and blob analysis. The detection method is based on a novel median filtering technique that involves enhancing of the image object based on its underlying structure and orientation in the image. The method when applied enhances the vertically oriented laser stripe in the image which improves the laser peak detection. The image processing steps are performed to make sure that the laser profile is accurately extracted within the region of interest (ROI). Feature extraction algorithm based on pixels’ intensity distribution and neighbourhood search is also proposed that can effectively extract the seam feature points. The proposed algorithms have been implemented and evaluated on various background complexities, seam sizes, material type and laser types before and during the welding operation.

Desorption behavior of zinc atoms from zinc-sulfate solution irradiated with pulsed DC plasma

A DC pulsed plasma ignited between a metal needle and zinc sulfate (ZnSO4) solution electrode was used to investigate Zn metal desorption from an electrolyte solution. Using an ICCD camera and optical band-pass filter, 2D atomic absorption spectroscopy was carried out during irradiation of pulsed plasma to the surface of the solution. The time-resolved measurement of Zn atoms released to the gas phase revealed that the Zn desorption rate monotonically increased with increasing number of discharge repetitions. The surface temperature of the electrolyte solution was observed with a thermographic camera, and correlations between the H2O and Zn desorption rate were inspected. The correlation between the H2O and Zn desorption rate suggested that Zn desorption is assisted not only by the electric field of the discharge but also by H2O evaporating from the solution.

Fluorescence imaging for photodynamic therapy of non-melanoma skin malignancies – A retrospective clinical study

Abstract Background and objective: Photodynamic therapy (PDT) has been successfully used in clinical practice for decades; however, clinical outcome data are not always consistent resulting in a great necessity for real-time monitoring to predict the therapy outcome. Study design and methods: In a retrospective clinical study, 402 patients with non-melanoma skin malignancies were enrolled who underwent PDT treatment and fluorescence real-time imaging. The photosensitizer used was a chlorine e6 derivative (Fotoditazin®); the tumors were irradiated with a 662 nm continuous wave diode laser with fiber delivery system and total fluence of up to 300 J/cm2. The fluorescence imaging was performed using a commercially available system with a camera and bandpass filter in the range of 710–800 nm. Fluorescence contrast (FC) of the tumor (the ratio of the average fluorescence intensities in the tumor and the surrounding tissues) and its change during the PDT treatment (photobleaching, dFC) was measured. Then the correlation between the clinical outcome (tumor response and recurrence rate) and measured fluorescence parameters was evaluated. The follow-up period was 6–53 months (median, 28 months). Results: FC or dFC below their median values independently correspond to a significant increase in tumor recurrence rate (p&lt;0.05), and slight increase of partial or no tumor response cases. Tumor response is better correlated with the value of FC, and not correlated with the photobleaching. Conclusion: Baseline FC and its change after PDT treatment may serve as a predictor of recurrence. This finding is a step towards individualized PDT cancer treatment.

A STUDY OF NEAR-INFRARED (NIR) FILTER FOR SURVEILLANCE APPLICATION

Lately, most illegal activities occur in the dead of night when most of the surveillance cameras cannot capture movements clearly. Therefore, Near-Infrared (NIR) filter was used to increase the visualization of suspect identification when the image or footage is captured in a dark environment. The objective of this study was to determine the optimum NIR filters based on the stability of the camera calibration parameters and to evaluate the accuracy of mapping. In this study, four NIR filters with different wavelengths (715, 780, 830, and 850 nm) were tested. The investigation comprised: (1) the calibrations of the camera and NIR filters and (2) a case study involving a simulation test for surveillance application. The type of sensor used was a digital video camera (Sony HC5E HDV) and the camera was set up at multiple stations to form a single convergence configuration. The statistical Analysis of Variance (ANOVA) was used in this study to find (differences in) the significance of the NIR imaging in the calibration and three-dimensional (3D) measurement. The results showed that the camera parameters varied for every type of filter used and this influenced the 3D measurement of the object mapping. In summary, the 850 nm NIR filter was the most optimum for surveillance application based on the stability of the camera calibration and the standard deviation in the mapping accuracy.

Sugar beet (Beta vulgaris L.) and thistle (Cirsium arvensis L.) discrimination based on field spectral data

Creeping thistle (Cirsium arvensis (L.) Scop.) is a perennial weed that causes yield loss in sugar beet (Beta vulgaris L.) crops. The weeds are usually mapped for site specific weed management because they tend to grow in patches. Remote sensing techniques have shown promising results in species discrimination and therefore provide potential for weed mapping. In this study we examined the feasibility of high-resolution imaging for sugar beet and thistle discrimination and proposed a protocol to select multispectral camera filters. Spectral samples from sugar beet and thistle were acquired with a field portable spectroradiometer under field conditions and Partial Least Squares Discriminant Analysis (PLS-DA) classification models were developed with 211 and 36 spectral features of 1.56 and 10 nm bandwidths, respectively. The classification rates obtained using these models were regarded as the maximum obtainable. Then, spectral responses of a multi-band camera equipped with the filter configuration proposed by the PLS-DA models were simulated. Finally, a simulation of crop-weed discrimination was made using small unmanned aerial vehicles (UAV)-based multispectral images. More than 95% of the thistles and 89% of the sugar beets were correctly classified when continuous spectral data were used with 1.56 and 10 nm bandwidths. Accuracy dropped to 93% of thistles identified and 84% of sugar beets correctly classified when only the four best bands were used. The validation based on aerial images showed that sugar beets and thistle plants could be discriminated in images if sufficient pure pixels containing leaf spectra were available, that is with spatial resolutions of 6 mm pixel−1 or finer.

Spatio-temporally resolved electron temperature in argon radio-frequency capacitive discharge at atmospheric pressure

Due to the lack of convincing experimental evidence for electron information, there are still unclearly understood discharge phenomena in atmospheric pressure radio-frequency (rf) capacitive discharge, e.g. the electron heating, discharge structures, and the alpha–gamma mode transition. Thus, to perceive basic and meaningful principles with an unambiguous interpretation, simple and reliable electron diagnostics are required. Since bremsstrahlung emitted through electron-neutral atom interaction depends on electron density (ne) and temperature (Te), their diagnostic is possible. In particular, Te is easily estimated from the ratio of bremsstrahlung emissivities at two different wavelengths or more. In this paper, 2D Te distribution in an argon atmospheric pressure capacitive discharge measured by using a digital camera and optical band pass filters is described. Time-averaged Te in the bulk region obtained by a digital camera is consistent with that measured by an absolutely calibrated spectrometer. In addition, time-resolved emission spectra and the corresponding ne and Te during one rf cycle of the argon capacitive discharge are discussed. The result shows that Te varied from 2.3 to 3.0 eV, while ne did not change significantly.

Continuum emission-based electron diagnostics for atmospheric pressure plasmas and characteristics of nanosecond-pulsed argon plasma jets

Electron diagnostics based on electron–neutral atom (e–a) bremsstrahlung in the UV and visible range emitted from atmospheric pressure plasmas is presented. Since the spectral emissivity of the e–a bremsstrahlung is determined by electron density (ne) and mean electron temperature (Te) representing the Maxwellian electron energy distribution, their diagnostics is possible. As an example, emission spectra measured from capacitive discharges are presented, which show good agreement with the theoretically calculated emissivity of the e–a bremsstrahlung. For a single pin electrode nanosecond-pulsed plasma jet (n-PPJ) in argon, we investigate the electron properties and the temporal behavior of the positive streamers. Streamers with many branches are clearly observed inside the dielectric tube, while a few main streamers propagate outside the tube along the jet axis. A two-dimensional (2D) measurement of the time-averaged Te distribution was developed using a commercial digital camera and optical band pass filters based on the emissivity ratio of two wavelengths of the e–a bremsstrahlung. The viable measurement range of Te is 0.5–7 eV for the choice of two wavelengths of 300s and 900s nm and 0.5–4 eV for two wavelengths of 400s and 900s nm, which are uncontaminated by the atomic and/or molecular spectra. The 2D Te distribution obtained using 514.5 and 632.8 nm emissions helps to reveal the role of electrons in streamer characteristics in the argon n-PPJ. Time-averaged Te of 2.0 eV and 1.0 eV inside and outside the tube, respectively, were measured. The streamer dynamics of the n-PPJ is shown to be dependent on Te.

Investigation of Droplet Ejection Mechanism from Electrode in Multi-Phase AC Arc

A multi-phase AC arc has various advantages such as high energy efficiency, large plasma volume and low gas velocity. Therefore, the multi-phase AC arc is suitable to massive powder processing like nanomaterial fabrication processes and innovative in-flight glass melting technology. However, the understanding of discharge behavior of multi-phase AC arc still remains to be improved for the practical use. In particular, electrode erosion is one of the most important issues to be solved. The purpose of this study is to investigate the droplet ejection mechanism of the multi-phase AC arc based on high-speed visualization by the high-speed camera and appropriate band-pass filters system. Obtained results indicated that droplet ejection was involved by variation in current and voltage during an AC cycle. The larger droplets were ejected at only cathodic period and the transition time from the cathodic to anodic AC period. Estimation of forces acting on the molten droplet revealed the electromagnetic force was most important force which leads to the detachment of the droplet from the electrode surface. Smaller droplet on the electrode tip leads to the droplet ejection due to the relatively stronger electromagnetic force than surface tension.

Temperature measurement of asymmetrical pulsed TIG arc plasma by multidirectional monochromatic imaging method

Arc plasma diagnostics by spectroscopy have been often used to measure the arc properties, such as the temperature. Measurements of an axially asymmetrical arc plasma require the optical computed tomography technique. This study constructed the simultaneous and multidirectional measurement system by six sets of CCD camera and interference filter with monochromatic imaging method. The deviation of the central wavelength of the filters was calibrated by tilting operation, and the sensitivity of detectors was calibrated by referencing the stationary and axially symmetric tungsten inert gas (TIG) arc plasma. We could perform the temperature measurement of the transient and asymmetrical TIG arc plasma such as in the transition period between the peak 150 A and base 10 A current of a 50 Hz pulsed TIG arc with 30° tilted torch. It was revealed that the high-temperature area of 30° tilted arc is larger than that of perpendicular arc. The comparison of pulsed and continuous arcs shows that the arc shape and the temperature variation reasonably followed the current change as long as the changing rate was about −113 A/ms.

Quantitative model-based imaging of mid-infrared radiation from a turbulent nonpremixed jet flame and plume

Current understanding of turbulent reacting flows can be improved by novel quantitative comparisons using highly scalable visualization methods based on volume rendering of time-dependent mid-infrared intensities in the form of images with multiple view angles. In this work, the effects of radiation and buoyancy in a turbulent nonpremixed flame and plume are studied by quantitatively comparing measured and computed images of the mid-infrared radiation intensity. To this end, a turbulent nonpremixed jet flame (Reynolds number 15,200 and CH4/H2/N2 fuel composition) is considered, representing a benchmark flame configuration of the International Workshop on Measurement and Computation of Turbulent Nonpremixed Flames (TNF Workshop). Quantitative images of the radiation intensity from the flame are acquired using a calibrated high-speed mid-infrared camera and band-pass filters. The camera and filters enable time-dependent measurements of radiation from water vapor and carbon dioxide over the entire flame length and beyond. Results of the solution to the radiative transfer equation are rendered in the form of images using scalar values from large eddy simulations (LES) and a narrowband radiation model. Planar images obtained from experiments and simulations for the radiation intensity display qualitatively comparable features, including localized regions of high and low intensity that are characteristic of turbulent flames. The quantitative comparison of the measured and computed temperature profiles and radiation intensities, particularly in the plume region downstream of the stoichiometric flame length, indicate that including radiation heat loss is important even for weakly radiating flames. The results demonstrate that quantitative experimental and model-based imaging of mid-infrared radiation intensity is useful for assessing the results of narrowband radiation and combustion models.

Vision-based weld pool boundary extraction and width measurement during keyhole fiber laser welding

In keyhole fiber laser welding processes, the weld pool behavior is essential to determining welding quality. To better observe and control the welding process, the accurate extraction of the weld pool boundary as well as the width is required. This work presents a weld pool edge detection technique based on an off axial green illumination laser and a coaxial image capturing system that consists of a CMOS camera and optic filters. According to the difference of image quality, a complete developed edge detection algorithm is proposed based on the local maximum gradient of greyness searching approach and linear interpolation. The extracted weld pool geometry and the width are validated by the actual welding width measurement and predictions by a numerical multi-phase model.

IPAC Image Processing and Data Archiving for the Palomar Transient Factory

The Palomar Transient Factory (PTF) is a multiepochal robotic survey of the northern sky that acquires data for the scientific study of transient and variable astrophysical phenomena. The camera and telescope provide for wide-field imaging in optical bands. In the five years of operation since first light on 2008 December 13, images taken with Mould-R and SDSS-g′ camera filters have been routinely acquired on a nightly basis (weather permitting), and two different Hα filters were installed in 2011 May (656 and 663 nm). The PTF image-processing and data-archival program at the Infrared Processing and Analysis Center (IPAC) is tailored to receive and reduce the data, and, from it, generate and preserve astrometrically and photometrically calibrated images, extracted source catalogs, and co-added reference images. Relational databases have been deployed to track these products in operations and the data archive. The fully automated system has benefited by lessons learned from past IPAC projects and comprises advantageous features that are potentially incorporable into other ground-based observatories. Both off-the-shelf and in-house software have been utilized for economy and rapid development. The PTF data archive is curated by the NASA/IPAC Infrared Science Archive (IRSA). A state-of-the-art custom Web interface has been deployed for downloading the raw images, processed images, and source catalogs from IRSA. Access to PTF data products is currently limited to an initial public data release (M81, M44, M42, SDSS Stripe 82, and the Kepler Survey Field). It is the intent of the PTF collaboration to release the full PTF data archive when sufficient funding becomes available.

Investigation of Electrode Phenomena in an Innovative Thermal Plasma Process for Glass Melting

A multi-phase alternating current (AC) arc has been applied to glass melting technology. The large volume discharge produced by a stable multi-phase AC arc is preferable to melt the granulated glass materials. The discharge behavior and the high-temperature region of the plasma can be controlled by the electrode configurations. In this study, the spatial characteristics of the arc discharge were examined by image analysis of high-speed camera. Results show arc existence area is related with electrode configuration. This study provides the useful information of efficient particle treatment in the preferred electrode configuration. However, the electrode erosion is one of the most considerable issues to be solved. The combination of high-speed video camera and band-pass filters was introduced to measure the electrode temperature to investigate the erosion mechanism of the multi-phase AC arc. The dynamic behavior of the electrode vapors in the arc was investigated by using the same high-speed camera system. Results show the tungsten electrode mainly evaporates at the anodic period during AC cycle.

Automated Analysis of Binocular Alignment Using an Infrared Camera and Selective Wavelength Filter

We present a computerized method of measuring binocular alignment using a selective wavelength filter and an infrared camera, and validate the efficacy of automated image analysis compared to the gold standard prism and alternate cover test (PCT). A prospective observational pilot study was performed on 30 subjects with intermittent exotropia, 30 subjects with esotropia, and 30 orthotropic subjects who were able to cooperate with the PCT. Two independent ophthalmologists examined the angle of deviation using the PCT. Full-face images were obtained with an infrared camera while a selective wavelength filter was placed in front of either eye. Images were analyzed using the 3D Strabismus Photo Analyzer. Interobserver variability, test-retest reliability and correlation between the angles of deviation were determined for both methods. The 95% limit of agreement of interobserver variability was ± 4.8 prism diopters (PD) for the PCT and ± 4.3 PD for the selective wavelength filter analysis. The 95% limit of agreement of test-retest reliability between the PCT and selective wavelength filter analysis was ± 8.5 PD. Results of the PCT and selective wavelength filter analysis showed a strong positive correlation (R = 0.900, P < 0.001). Infrared images acquired with a selective wavelength filter can detect the latent components of strabismus, and automated image analysis showed excellent agreement with the standard PCT. This automated method is an accurate and reliable tool for measuring ocular deviation with minimal observer dependency.

Development of new two-component temperature-sensitive paint (TSP) for cryogenic testing

Two-component temperature-sensitive paint (TSP) for cryogenic wind tunnels has been newly developed to extend the highest working temperature up to 320 K, whereas a conventional single-component cryoTSP operates in the temperature range from 100 to 240 K. The two-component cryoTSP includes two luminophores: a ruthenium complex (Ru(trpy)2) and a europium complex, which are very temperature sensitive in the range of 100–240 K and 220–320 K, respectively. The ruthenium complex is excited by blue light while the europium complex requires UV light. One can thence operate the two luminophores independently by illuminating the paint at different wavelengths. Both luminophores emit red light, so that it is possible to use a single camera filter to observe both luminophores. Verification tests at different cryogenic wind tunnels proved that the two-component cryoTSP could detect a boundary layer transition line even up to room temperatures with only a single coating. This means that it is neither necessary to apply a different TSP coating to a model nor use an infrared camera when the wind tunnel is operated at room temperatures. As a result, the two-component cryoTSP enables one to save time and money in cryogenic testing.