Bright Background Research Articles

A Spatiotemporal Contextual Model for Forest Fire Detection Using Himawari-8 Satellite Data

Two of the main remote sensing data resources for forest fire detection have significant drawbacks: geostationary Earth Observation (EO) satellites have high temporal resolution but low spatial resolution, whereas Polar-orbiting systems have high spatial resolution but low temporal resolution. Therefore, the existing forest fire detection algorithms that are based on a single one of these two systems have only exploited temporal or spatial information independently. There are no approaches yet that have effectively merged spatial and temporal characteristics to detect forest fires. This paper fills this gap by presenting a spatiotemporal contextual model (STCM) that fully exploits geostationary data’s spatial and temporal dimensions based on the data from Himawari-8 Satellite. We used an improved robust fitting algorithm to model each pixel’s diurnal temperature cycles (DTC) in the middle and long infrared bands. For each pixel, a Kalman filter was used to blend the DTC to estimate the true background brightness temperature. Subsequently, we utilized the Otsu method to identify the fire after using an MVC (maximum value month composite of NDVI) threshold to test which areas have enough fuel to support such events. Finally, we used a continuous timeslot test to correct the fire detection results. The proposed algorithm was applied to four fire cases in East Asia and Australia in 2016. A comparison of detection results between MODIS Terra and Aqua active fire products (MOD14 and MYD14) demonstrated that the proposed algorithm from this paper effectively analyzed the spatiotemporal information contained in multi-temporal remotely sensed data. In addition, this new forest fire detection method can lead to higher detection accuracy than the traditional contextual and temporal algorithms. By developing algorithms that are based on AHI measurements to meet the requirement to detect forest fires promptly and accurately, this paper assists both emergency responders and the general public to mitigate the damage of forest fires.

Smart data driven traffic sign detection method based on adaptive color threshold and shape symmetry

Detection and recognition of road traffic signs constitute an important element in Advanced Driver Assistance Systems (ADAS), which can provide real-time road sign perception information to vehicles. In this paper, we proposed a new traffic sign detection method based on adaptive color threshold segmentation and the hypothesis testing of shape symmetry by leveraging traffic signs and image data. First, we calculated an adaptive segmentation threshold using the cumulative distribution function of the image histogram. Based on this, we designed an approximate maximum and minimum normalization method, which is used to suppress the interference of high brightness area and background in image thresholding processes. Secondly, we transformed the highlight shape feature of thresholding image into a connected domain feature vector. And we formulated a shape symmetry detection algorithm based on statistical hypothesis testing to efficiently extract the ROI of traffic signs based on traffic data analysis. We performed some comprehensive experiments on the GTSDB (German Traffic Sign Detection Benchmark) dataset. The accuracy of traffic sign detection exceeded 94%. This method has higher detection accuracy and time efficiency than other methods, and better robustness under complex traffic environment.

Galaxies Probing Galaxies in PRIMUS. II. The Coherence Scale of the Cool Circumgalactic Medium

Abstract The circumgalactic medium (CGM) close to ∼L* star-forming galaxies hosts strong Mg ii λ2796 absorption (with equivalent width W 2796 > 0.1 Å) with a near-unity covering fraction. To characterize the spatial coherence of this absorption, we analyze the W 2796 distribution in the CGM of 27 star-forming galaxies detected in deep spectroscopy of bright background (b/g) galaxies first presented in Rubin et al. The sample foreground (f/g) systems have redshifts and stellar masses 9.1 < log M */M ⊙ < 11.1, and the b/g galaxies provide spatially extended probes with half-light radii at projected distances < 50 kpc. Our analysis also draws on literature W 2796 values measured in b/g QSO spectroscopy probing the halos of f/g galaxies with a similar range in M * at z ∼ 0.25. By making the assumptions that (1) samples of like galaxies exhibit similar circumgalactic W 2796 distributions and, (2) within a given halo, the quantity log W 2796 has a Gaussian distribution with a dispersion that is constant with M * and , we use this QSO–galaxy pair sample to construct a model for the log W 2796 distribution in the CGM of low-redshift galaxies. Adopting this model, we then demonstrate the dependence of the observed log W 2796 distribution on the ratio of the surface area of the b/g probe to the projected absorber surface area (x A ≡ A G/A A), finding that distributions that assume x A ≥ 15 are statistically inconsistent with that observed toward our b/g galaxy sample at a 95% confidence level. This limit, in combination with the b/g galaxy sizes, requires that the length scale over which W 2796 does not vary (i.e., the “coherence scale” of Mg ii absorption) is ℓ A > kpc. This novel constraint on the morphology of cool, photoionized structures in the inner CGM suggests that either these structures each extend over kiloparsec scales or the number and velocity dispersion of these structures are spatially correlated over the same scales.

Effect of Background Brightness on the Visibility of Foreground Colors under Artificial Weather Conditions - Focused on the fog and rain conditions

Effect of Background Brightness on the Visibility of Foreground Colors under Artificial Weather Conditions - Focused on the fog and rain conditions

Prominence activation, optical flare, and post-flare loops on the RS Canum Venaticorum star SZ Piscium

We present the results of time-resolved high-resolution spectroscopic observations of the very active RS Canum Venaticorum (RS CVn) star SZ Piscium (SZ Psc), obtained during two consecutive observing nights on 2011 October 24 and 25. Several optical chromospheric activity indicators are analysed using the spectral subtraction technique, which show the remarkably different behaviour between two nights. Gradually blue-shifted and strengthened excess absorption features presented in the series of the subtracted spectra (especially for the H alpha, He I D-3, and H beta lines), as a result of active stellar prominence that is rising its height along the line of our sight, was detected in the observations on October 24. This prominence activation event was probably associated with the subsequently occurred optical flare, and part of that flare decay phase was hunted in the observations on October 25. The flare was characterized by the prominent He I D-3 line emission, as well as stronger chromospheric emission in the H alpha, H beta, and other active lines. The gradual decay of flare was accompanied by an obviously developmental absorption feature in the blue wing of the H alpha and other active lines, which could be explained as cool post-flare loops which projected against the bright flare background. Therefore, a series of possibly associated magnetic activity phenomena, including flare-related prominence activation, optical flare, and post-flare loops, were detected during our observations.

Hyperspectral imaging: a novel approach for plant root phenotyping

BackgroundRoot phenotyping aims to characterize root system architecture because of its functional role in resource acquisition. RGB imaging and analysis procedures measure root system traits via colour contrasts between roots and growth media or artificial backgrounds. In the case of plants grown in soil-filled rhizoboxes, where the colour contrast can be poor, it is hypothesized that root imaging based on spectral signatures improves segmentation and provides additional knowledge on physico-chemical root properties.ResultsRoot systems of Triticum durum grown in soil-filled rhizoboxes were scanned in a spectral range of 1000–1700 nm with 222 narrow bands and a spatial resolution of 0.1 mm. A data processing pipeline was developed for automatic root segmentation and analysis of spectral root signatures. Spectral- and RGB-based root segmentation did not significantly differ in accuracy even for a bright soil background. Best spectral segmentation was obtained from log-linearized and asymptotic least squares corrected images via fuzzy clustering and multilevel thresholding. Root axes revealed major spectral distinction between center and border regions. Root decay was captured by an exponential function of the difference spectra between water and structural carbon absorption regions.ConclusionsFundamentals for root phenotyping using hyperspectral imaging have been established by means of an image processing pipeline for automated segmentation of soil-grown plant roots at a high spatial resolution and for the exploration of spectral signatures encoding physico-chemical root zone properties.

Nearly all the sky is covered by Lyman-α emission around high-redshift galaxies.

Galaxies are surrounded by large reservoirs of gas, mostly hydrogen, that are fed by inflows from the intergalactic medium and by outflows from galactic winds. Absorption-line measurements along the lines of sight to bright and rare background quasars indicate that this circumgalactic medium extends far beyond the starlight seen in galaxies, but very little is known about its spatial distribution. The Lyman-α transition of atomic hydrogen at a wavelength of 121.6 nanometres is an important tracer of warm (about 104 kelvin) gas in and around galaxies, especially at cosmological redshifts greater than about 1.6 at which the spectral line becomes observable from the ground. Tracing cosmic hydrogen through its Lyman-α emission has been a long-standing goal of observational astrophysics1-3, but the extremely low surface brightness of the spatially extended emission is a formidable obstacle. A new window into circumgalactic environments was recently opened by the discovery of ubiquitous extended Lyman-α emission from hydrogen around high-redshift galaxies4,5. Such measurements were previously limited to especially favourable systems6-8 or to the use of massive statistical averaging9,10 because of the faintness of this emission. Here we report observations of low-surface-brightness Lyman-α emission surrounding faint galaxies at redshifts between 3 and 6. We find that the projected sky coverage approaches 100 per cent. The corresponding rate of incidence (the mean number of Lyman-α emitters penetrated by any arbitrary line of sight) is well above unity and similar to the incidence rate of high-column-density absorbers frequently detected in the spectra of distant quasars11-14. This similarity suggests that most circumgalactic atomic hydrogen at these redshifts has now been detected in emission.

Stellar masses, metallicity gradients, and suppressed star formation revealed in a new sample of absorption selected galaxies

Context. Absorbing galaxies are selected via the detection of characteristic absorption lines which their gas-rich media imprint in the spectra of distant light-beacons. The proximity of the typically faint foreground absorbing galaxies to bright background sources makes it challenging to robustly identify these in emission, and hence to characterise their relation to the general galaxy population. Aims. We search for emission to confirm and characterise ten galaxies hosting damped, metal-rich quasar absorbers at redshift z < 1. Methods. We identified the absorbing galaxies by matching spectroscopic absorption -and emission redshifts and from projected separations. Combining emission-line diagnostics with existing absorption spectroscopy and photometry of quasar-fields hosting metal-rich, damped absorbers, we compare our new detections with reference samples and place them on scaling relations. Results. We spectroscopically confirm seven galaxies harbouring damped absorbers (a 70% success-rate). Our results conform to the emerging picture that neutral gas on scales of tens of kpc in galaxies is what causes the characteristic H I absorption. Our key results are: (I) Absorbing galaxies with log10[M⋆,(M⊙)] ≳ 10 have star formation rates that are lower than predicted for the main sequence of star formation. (II) The distribution of impact parameter with H I column density and with absorption-metallicity for absorbing galaxies at z ∼ 2–3 extends to z ∼ 0.7 and to lower H I column densities. (III) A robust mean metallicity gradient of ⟨Γ⟩ = −0.022 ± 0.001 dex kpc−1. (IV) By correcting absorption metallicities for ⟨Γ⟩ and imposing a truncation-radius at 12 kpc, absorbing galaxies fall on top of predicted mass-metallicity relations, with a statistically significant decrease in scatter.

Divided Visual Attention Performance of Ice Hockey Players with History of Concussion

Background: A significant part of successful athletic performance is the use of peripheral vision. A divide visual attention task with a central and peripheral target was used to assess athletes with and without a history of concussion. The research suggests that both groups had the same response accuracy in the task performance. The purpose of this research was to determine if peripheral visual attention is impacted in ice hockey players who have had a history of one or more self reported concussion. Methods: Orientation discrimination accuracy of a pair of Landolt type block “C” targets was measured using a divided covert attention task on 22 collegiate level men’s ice hockey players. Stimuli were presented simultaneously at central fixation and at one of 40 peripheral locations against a bright white background for two stimulus durations (150ms and 15ms). Block “C” targets were presented at one of 4 orientations (up, down, left and right) and randomized for central and peripheral locations. Results: Overall there was a statistically significant difference in the performance at 150ms and 15ms stimuli durations; athletes had a larger area of correct responses with the 150ms stimulus duration. Athletes performed better in the horizontal meridian compared to the vertical meridian for both stimulus durations. Conclusion: The divided visual attention test results for a cohort of university level men’s ice hockey players shows a decline in area of correct responses with shorter stimulus durations. There was no difference in response accuracy between those with a history of a concussion compared to those without a previous concussion.

Probing the dynamical state, baryon content, and multiphase nature of galaxy clusters with bright background QSOs

We have initiated a programme to study the physical/dynamical state of gas in galaxy clusters and the impact of the cluster environment on gaseous halos of individual galaxies using X-ray imaging and UV absorption line spectroscopy of background QSOs. Here we report results from the analysis Chandra and XMM-Newton archival data of five galaxy clusters with such QSOs, one of which has an archival UV spectrum. We characterize the gravitational masses and dynamical states, as well as the hot intracluster medium (ICM) properties of these clusters. Most clusters are dynamically disturbed clusters based on the X-ray morphology parameters, the X-ray temperature profiles, the large offset between X-ray peak and brightest cluster galaxy (BCG). The baryon contents in the hot ICM and stars of these clusters within $r_{500}$ are lower than the values expected from the gravitational masses, according to the standard cosmology. We also estimate column densities of the hot ICM along the sightlines toward the background QSOs as well as place upper limits on the warm-hot phase for the one sightline with existing UV observations. These column densities, compared with those of the warm and warm-hot ICM to be measured with UV absorption line spectroscopy, will enable us to probe the relationship among various gaseous phases and their connection to the heating/cooling and dynamical processes of the clusters. Furthermore, our analysis of the archival QSO spectrum probing one cluster underscores the need for high quality, targeted UV observations to robustly constrain the 10$^{5-6}$ K gas phase.

On the role of transient depolarization-activated K+ current in microvillar photoreceptors.

Photoreceptors in the compound eyes of most insect species express two functional types of depolarization-activated potassium currents: a transient A-type current (IA) and a sustained delayed rectifier current (IDR). The role of Shaker-dependent IA in Drosophila melanogaster photoreceptors was previously investigated by comparing intracellular recordings from Shaker and wild-type photoreceptors. Shaker channels were proposed to be involved in low-frequency signal amplification in dim light and reduction of the metabolic cost of information transfer. Here, I study the function of IA in photoreceptors of the cockroach Panchlora nivea using the patch-clamp method. Responses to Gaussian white-noise stimuli reveal that blockade of IA with 4-aminopyridine has no discernible effect on voltage responses or information processing. However, because open-channel blockers are often ineffective at low membrane potentials, no conclusion on the role of IA could be made on the basis of negative results of pharmacological tests. Using a relatively large set of control data, a physiological variability analysis was performed to discern the role of IA. Amplitudes of the IA window current and half-activation potentials correlate strongly with membrane corner frequencies, especially in dim light, indicating that IA facilitates transmission of higher frequencies. Consistent with voltage-dependent inactivation of IA, these correlations decrease with depolarization in brighter backgrounds. In contrast, correlations involving IDR are comparatively weak. Upon reexamining photoreceptor conductance in wild-type and Shaker strains of D. melanogaster, I find a biphasic voltage dependence near the resting potential in a minority of photoreceptors from both strains, indicating that Shaker channels are not crucial for early amplification of voltage signals in D. melanogaster photoreceptors. Leak current in Shaker photoreceptors at the level of the soma is not elevated. These results suggest a novel role for IA in facilitating transmission of high-frequency signals in microvillar photoreceptors.

The effect of magnetic field morphology on the structure of massive IRDC clumps

Infrared dark clouds (IRDCs) have dense elongated clumps and filaments with the favorable viewing condition of being on the near-side of a bright mid-infrared background. The clumps usually have multiple cores around the center. In this work, we study the effect of magnetic field morphology on the structure of massive IRDC clumps. To achieve this goal, we consider an axisymmetric isothermal oblate IRDC clump, embedded into a constant external magnetic field. We assume a polynomial function for the magnetic field morphology inside the clump. We use the numerical iterative methods to solve the equations: the successive over-relaxation method to find the magnetic and gravitational fluxes, and then the bicongugate gradient method to find the optimized values of mass and current densities. The results show that the IRDC clump will be very elongated along the perpendicular direction of the external magnetic field lines. Also, the assumption of choosing of a polynomial function for the magnetic field morphology leads to the formation of dense regions around the center. The greater the density of the central region, the larger the density of these dense regions and the closer to the center. The presence of these dense regions can lead to the formation of cores at these points.

DLA and sub-DLA metallicity evolution: A case study of absorbers towards Q0338-0005

The damped and sub-damped Lyα systems (DLAs and sub-DLAs) traced in absorption against bright background quasars represent the main reserve of neutral hydrogen at high redshifts. We used the archival Very Large Telescope (VLT) instrument Ultraviolet and Visual Echelle Spectrograph (UVES) high-resolution data of Q 0338-0005 (zem=3.049) to study the abundances of the DLA (zabs=2.2298) and sub-DLA (zabs=2.7457) along the line of sight. We estimated column densities of H i and various elements present in the DLA and sub-DLA through Voigt profile fitting. The DLA throgh shows the Lyα emission from its host galaxy. We derive the metallicities of the DLA and sub-DLA with [Zn/H] =−0.67±0.18 and [S/H] =−1.45±0.17, respectively. We compared our abundances of the DLA and sub-DLA with other high-resolution DLA and sub-DLA metallicities and find that both populations show an overall increase of metallicity with decreasing redshift. However, sub-DLAs have higher metallicities than the DLAs.

Calibrating the HISA temperature: Measuring the temperature of the Riegel–Crutcher cloud

HI self absorption (HISA) clouds are clumps of cold neutral hydrogen (HI) visible in front of warm background gas, which makes them ideal places to study the properties of the cold atomic component of the interstellar medium (ISM). The Riegel-Crutcher (R-C) cloud is the most striking HISA feature in the Galaxy. It is one of the closest HISA clouds to us and is located in the direction of the Galactic Centre, which provides a bright background. High-resolution interferometric measurements have revealed the filamentary structure of this cloud, however it is difficult to accurately determine the temperature and the density of the gas without optical depth measurements. In this paper we present new HI absorption observations with the Australia Telescope Compact Array (ATCA) against 46 continuum sources behind the Riegel-Crutcher cloud to directly measure the optical depth of the cloud. We decompose the complex HI absorption spectra into Gaussian components using an automated machine learning algorithm. We find 300 Gaussian components, from which 67 are associated with the R-C cloud (0 < v_{LSR} < 10 kms, FWHM < 10 kms). Combining the new HI absorption data with HI emission data from previous surveys we calculate the spin temperature and find it to be between 20 and 80 K. Our measurements uncover a temperature gradient across the cloud with spin temperatures decreasing towards positive Galactic latitudes. We also find three new OH absorption lines associated with the cloud, which support the presence of molecular gas.

Jonathan Murray, The New Scottish Cinema

The cover of Jonathan Murray’s most recent book, examining the development of Scottish cinema from the 1990s to the 2000s, features a striking image from Red Road (Andrea Arnold, 2006). The actor Kate Dickie, who plays the lead character of Jackie, is rendered in dark profile against a bright yellow background, her identity obscured by the high-contrast lighting. The film, an apt choice for the book’s cover, was produced as part of the Advance Party initiative, led by Glasgow-based Sigma Films, and the Danish production company Zentropa, and is one of a number of films produced in Scotland in the 2000s that Murray describes as having demonstrated ‘the extent to which traditional ideas of a deliberate, dominant and didactic focus on the question of nation are not straightforwardly applicable to a significant proportion of contemporary Scottish filmmaking’ (p. 175). The image from Red Road was the key image used for the worldwide promotion of the film, serving to give a sense of the film’s narrative focus and Jackie’s literal position in the dark in her daily work as a CCTV operator, but also acting as an indicator of the film’s deliberate positioning as a transnational film. The image is notable for its lack of obvious identifiers with its Scottish context. The identity obscured is not only Jackie’s but Scotland’s; the film’s location, as its narrative image suggests, could be anywhere.1

Improved space object detection using short-exposure image data with daylight background.

Space object detection is of great importance in the highly dependent yet competitive and congested space domain. The detection algorithms employed play a crucial role in fulfilling the detection component in the space situational awareness mission to detect, track, characterize, and catalog unknown space objects. Many current space detection algorithms use a matched filter or a spatial correlator on long-exposure data to make a detection decision at a single pixel point of a spatial image based on the assumption that the data follow a Gaussian distribution. Long-exposure imaging is critical to detection performance in these algorithms; however, for imaging under daylight conditions, it becomes necessary to create a long-exposure image as the sum of many short-exposure images. This paper explores the potential for increasing detection capabilities for small and dim space objects in a stack of short-exposure images dominated by a bright background. The algorithm proposed in this paper improves the traditional stack and average method of forming a long-exposure image by selectively removing short-exposure frames of data that do not positively contribute to the overall signal-to-noise ratio of the averaged image. The performance of the algorithm is compared to a traditional matched filter detector using data generated in MATLAB as well as laboratory-collected data. The results are illustrated on a receiver operating characteristic curve to highlight the increased probability of detection associated with the proposed algorithm.

Visual crypsis as a possible function of polymorphic shell coloration in the infaunal clam Ruditapes philippinarum

The infaunal clam Ruditapes philippinarum exhibits highly polymorphic shell coloration, but the function of the coloration remains uncertain. Here, a hypothesis that such shell coloration functions to enhance visual crypsis (i.e., background color matching) in juveniles (<15 mm in shell length) was tested with a combination of a field survey and laboratory experiments. Shell and background colorations were expressed as mean brightness values. Firstly, the association between shell and background brightness was investigated. For this, a field survey for two sympatric subpopulations with distinct substrates was conducted on an intertidal sandflat in western Kyushu, Japan. Secondly, the visual-crypsis hypothesis was tested experimentally using half-valve clam shells filled with paste of raw clam meat as prey and the pufferfish Takifugu niphobles as a visually hunting predator, in a tank with one to two dark-colored substrates and one light-colored substrate. The field survey showed that shell brightness significantly differed between the two sympatric subpopulations of juvenile clams and was positively associated with background brightness. The laboratory experiments indicated that prey items with comparatively light (dark) coloration on dark- (light-) colored substrate were consumed by predators more immediately and at a higher rate than in the color-matched combinations. Consequently, shell–background color matching could help juvenile clams avoid attack from visually hunting predators. The results provide a new insight into effective management planning for this clam species, creating sand habitats with a more matched coloration.

Absorption by Spinning Dust: A Contaminant for High-redshift 21 cm Observations

Abstract Spinning dust grains in front of the bright Galactic synchrotron background can produce a weak absorption signal that could affect measurements of high-redshift 21 cm absorption. At frequencies near 80 MHz where the Experiment to Detect the Global EoR Signature (EDGES) has reported 21 cm absorption at z ≈ 17 , absorption could be produced by interstellar nanoparticles with radii a ≈ 50 Å in the cold interstellar medium (ISM), with rotational temperature T ≈ 50 K. Atmospheric aerosols could contribute additional absorption. The strength of the absorption depends on the abundance of such grains and on their dipole moments, which are uncertain. The breadth of the absorption spectrum of spinning dust limits its possible impact on measurement of a relatively narrow 21 cm absorption feature.

MULTIMODAL IMAGING OF MOSAIC RETINOPATHY IN CARRIERS OF HEREDITARY X-LINKED RECESSIVE DISEASES.

To investigate the clinical features in carriers of X-linked retinitis pigmentosa, X-linked ocular albinism, and choroideremia (CHM) using multimodal imaging and to assess their diagnostic value in these three mosaic retinopathies. We prospectively examined 14 carriers of 3 X-linked recessive disorders (X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM). Details of abnormalities of retinal morphology were evaluated using fundus photography, fundus autofluorescence (FAF) imaging, and spectral domain optical coherence tomography. In six X-linked retinitis pigmentosa carriers, fundus appearance varied from unremarkable to the presence of tapetal-like reflex and pigmentary changes. On FAF imaging, all carriers exhibited a bright radial reflex against a dark background. By spectral domain optical coherence tomography, loss of the ellipsoid zone in the macula was observed in 3 carriers (50%). Regarding the retinal laminar architecture, 4 carriers (66.7%) showed thinning of the outer nuclear layer and a dentate appearance of the outer plexiform layer. All five X-linked ocular albinism carriers showed a characteristic mud-splatter patterned fundus, dark radial streaks against a bright background on FAF imaging, and a normal-appearing retinal structure by spectral domain optical coherence tomography imaging. Two of the 3 CHM carriers (66.7%) showed a diffuse moth-eaten appearance of the fundus, and all 3 showed irregular hyper-FAF and hypo-FAF spots throughout the affected area. In the CHM carriers, the structural changes observed by spectral domain optical coherence tomography imaging were variable. Our findings in an Asian cohort suggest that FAF imaging is a practical diagnostic test for differentiating X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM carriers. Wide-field FAF is an easy and helpful adjunct to testing for the correct diagnosis and identification of lyonization in carriers of these three mosaic retinopathies.

Additive colours approach for dental ceramics translucency characteristics made from Sumatra and Java natural sands

Translucency is one of dental ceramics desirable aesthetic characteristics, which can be used as an indirect restoration. Dental ceramics can also be made using Computed Aided Design/Computer Aided Manufacturing (CAD/CAM) unit that can create variety blocks as an ingot into a customized restoration. This paper presents the results of self-synthesized porcelain blocks generated from natural sand of Sumatera and Java Islands to promote national independency. This research aims to determine the translucency of dental ceramics made from Indonesia’s natural sand. Six samples each of two different synthesized temperatures, 1150 °C and 1200 °C, were made. To analyse translucency of the sample, their image was taken in bright light background in a black box, then additive green and blue colours histogram channel with range 0 (opaque) to 255 (transparent) were evaluated using Matlab R2015B. The result revealed that mean of green peaks on 1150 °C has an average translucency value of 41%, compared to 34% of blue peaks. Lower percentage of translucency, 31% and 25% on the green and blue channel respectively were attained in samples synthesized in 1200 °C. These suggest that 1150 °C is the optimum temperature for translucency for these ceramic samples from natural sands as they contain leucite crystals shown by the XRD analyses as a result of silica-undersaturated mixture indicated by the Electron Dispersive Spectroscopy. SEM (Scanning Electron Microscope) results show remnant of air pocket in the samples sintered at higher temperature.In conclusion, natural sand from Sumatera and Java can be considered as reliable, cheap basic material options in developing self-synthesized dental ceramics with a desirable translucency. These preliminary results indicate that better balance between strength and translucency could potentially be achieved by making nano-sized dental ceramics.