Epson Expression 10000XL Scanner Research Articles

Test of the scanner for expression the astrometric and photometric parameters from the digitized plates

This paper performs to research in detail the Epson Expression 10000XL scanner for photographic astroplate archive of the Ulugh Beg Astronomical Institute (UBAI) of the Uzbekistan Academy of Sciences. For processing the astroplates, it is used special developed software in the LINUX/MIDAS/ROMAFOT. The test plate was digitized with grayscale 8 and 16 bits with various scanner resolutions. Astronomical and photometric parameters were carried out from the plate and an evaluation of the developed method accuracy for determining rectangular coordinates and photometry. The repeatability of astrometric and photometric errors of the scanner for the digitized resolutions, 6 successive scans of every plate with a spatial resolution 600, 900, 1200, 1500, 1800, 2100, 2400 and 2540 dpi were processed.

THE ASTROMETRIC AND PHOTOMETRIC RESULTS OF DIGITIZED PLATES ON EPSON EXPRESSION 10000XL SCANNER WITH DIFFERENT RESOLUTIONS

This work was done to assess the accuracy of the plate processing method and to study in detail the Epson Expression 10000XL scanner, which is used to digitize the FON-Kitab astronomical plates from the photographic archive collection of the Ulugh Beg Astronomical Institute (UBAI) of the Uzbekistan Academy of Sciences. The glass archive of the UBAI has about 15 thousand photographic plates with images of various space objects. To process the plates the specially developed software in the LINUX/MIDAS/ROMAFOT was used. From comparing the results of processing digitized files with grayscale 8 and 16 bits, an assessment of the accuracy of the developed method for determining rectangular coordinates and photometry was made. The Epson Expression 10000XL flatbed scanner together with developed software can be used to digitize and process the astronegatives and obtain characteristics of objects (high, medium and moderate brightness) with an internal accuracy better than 0.05ʺ and 0.015 m for equatorial coordinates and B-magnitudes, respectively. To assess the repeatability of astrometric and photometric errors of the scanner, six consecutive scans of one plate with 600, 900, 1200, 1500, 1800, 2100, 2400 and 2540 dpi spatial separations were processed. The average accuracies of measurements were σ αδ =0.07ʺ for the equatorial coordinates and σ m =0.13 m for B-magnitudes. The results of the xperiments showed that a scan mode with a spatial resolution of 1200 dpi is the best option for plate digitization. Higher resolution scanning modes require a significant increase of digitizing and processing times of a plate, but they do not affect on an accuracy of the obtained results.

Catalog of equatorial coordinates and B‐magnitudes of the Kitab's part of the FON project

AbstractWe present a catalog of stars with equatorial coordinates α and δ and B‐magnitudes of stars for the Kitab's section of the FON project (FON‐Kitab). The photographic plates of the FON project were exposed on the double telescope Double Zeiss Astrograph (DAZ, D/F = 40/300, 69″/mm) at the Kitab observatory of the Republic of Uzbekistan. A total of 1963 plates, with size of 5.5 × 5.5 degrees (30 × 30 cm or 13,000 × 13,000 pixels) were digitized by Epson Expression 10000XL scanner with 1,200 dpi resolution. The reduction of plates was processed in the four astronomical organizations: Ulugh Beg Astronomical Institute (UBAI) of the Uzbek Academy of Sciences; the Mykolaiv Astronomical Observatory of the Ministry of Education and Science of Ukraine; the Walter Hohmann Observatory of Essen, Germany; and the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. The catalogue contains nearly 13.4 million stars and galaxies from 0° to −20° according to declination down to B = 17. m5 in the middle epoch of observation 1985.0. The coordinates of the stars and galaxies were obtained from the Tycho‐2 catalogue, while B‐magnitudes were determined in the system of photoelectric standards. The mean internal errors of the new catalogue for all objects were σαδ = 0. ′′23 and σB = 0. m15 (for the stars in the range of B = 5m − 14m, the errors are σαδ = 0. ′′085 and σB = 0. m054 for the equatorial coordinates and the B‐magnitudes, respectively). The convergence between the calculated and reference positions was σαδ = 0. ′′042. The convergence with the photoelectric B‐magnitudes is σB = 0. m16. External comparison with UCAC‐4 based on 9,892,697 or 73.8% cross‐identified objects yield σαδ = 0. ′′26.

BALDONE 1.2M TELESCOPE PLATE ARCHIVE - HIDDEN RESERVES OF THE FON PROJECT

The plate archive of the 1.2 m Baldone telescope (Latvia) has approximately 780 and 4660 astronegatives exposed in 1967-1993 in the U (ZU21 + UG1 filter plates) and V (A600N + ZS17 filter films) closed to Johnson system U and V passbands. Digitization of astronegatives is carried out using the Epson Expression 10000XL scanner, the scanning mode is 1200 or 2400 dpi, each field covers 19 square degrees of sky. The plates and films are scanned at the Baldone Observatory, processing of digitized scans is carried out by the observers in Baldone, at the Research Institute Mykolaiv Astronomical and at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. The Epson Expression 10000XL Scanner, along with the software developed, allows us to digitize and process the plates and receive coordinates and magnitudes of registered objects (with high, moderate and low brightness) with an internal error of no worse than 0.05 seconds of arc and 0.03 magnitude. The astrometric and photometric reduction of digitized astronegatives is done in the Tycho-2 reference system and U, V photoelectric system. At this report, we present first results of reduction of more than 2000 astronegatives. Data of U and V magnitudes of stars and galaxies will be used as the photometric addition to the FON project, without, the long-term series of U, V observations have an independent value for studying the variability of stars. Also, many plates included open clusters and will be used for investigation of their population and photometric parallaxes.

CATALOGUE OF COORDINATES AND B-MAGNITUDES IN - 20є – +2є ZONE BASED ON THE ULUGH BEG ASTRONOMICAL INSTITUTE PART OF THE FON PROJECT

Catalogue of 13.4 million stars down to 17.5m was obtained in 2017 by using plates from the Kitab Observatory of Ulugh Beg Astronomical Institute (UBAI) of the Uzbek Academy of Sciences. Kitab's part of Photographic Sky Survey (Russian abbreviation is FON, in next contexts) project include more than 2600 photographic plates, exposed on the Double Astrograph of Zeiss (DAZ, D/F = 40/300, 69/mm) from 1981 to 1996. Digitizationof these plates was made by using Epson Expression 10000XL scanner with the 1200 dpi resolution. Catalogue includes objects from the 1963 plates in declination zone between -20° and +2° for middle epoch 1984.97. The equatorial coordinates of objects were determined in the Tycho-2 reference system and the B-magnitudes in the system of the photoelectric standards. Five participants from Uzbekistan, Germany and Ukraine have taken part in the processing of the digitized images. The average internal accuracy of the catalogue for one observation are 0.23 and 0.15m for the equatorial coordinates and B-magnitudes respectively. For the stars brighter than 14m the errors are 0.09 and 0.05m respectively. The analysis of the catalogue and its comparison with the several astrometric catalogues was done.

Catalog of equatorial coordinates and B-magnitudes of stars of the Kitab part of the FON project

The processing of the plates of the Kitab part of the FON project has been completed. In total, 1963 plates were processed. The catalog of equatorial coordinates α, δ, and B-magnitudes for 13 413268 stars and galaxies up to B ≤ 17.5 m for the epoch 1984.97 is compiled. The Epson Expression 10000XL scanner with a 1200 dpi scanning mode and a plate size of 30 × 30 cm or 13000 × 13000 pel was used to digitize astronegatives. Coordinates of stars and galaxies are obtained in the Tycho-2 catalog system and B-magnitudes are obtained in the photovoltaic system. The catalog internal accuracy for all objects is σα,δ = 0.23" and σ B = 0.15 m (for stars in the range B = 5 m …14 m , errors are σα,δ = 0.085" and σ B = 0.054 m ) for equatorial coordinates and stellar B-magnitudes, respectively. Convergence between the calculated and reference positions is σα,δ = 0.042", and convergence between photoelectric B-magnitudes is σ B = 0.16 m . Coordinate errors with respect to the UCAC-4 catalog are σα,δ = 0.26" (9892697 or 73.75% of stars and galaxies were identified).

Processing of Digital Plates1.2m of Baldone Observatory Schmidt Telescope

Abstract The aim of this research is to evaluate accuracy of Plate Processing Method and to perform a detailed study of the Epson Expression 10000XL scanner, which was used to digitize plates from the database collection of the 1.2 m Schmidt Telescope installed in the Baldone Observatory. Special software developed in LINUX/MIDAS/ROMAFOT environment was used for processing the scans. Results of the digitized files with grey gradations of 8- and 16-bits were compared; an estimation of the accuracy of the developed method for rectangular coordinates determination and photometry was made. Errors in the instrumental system are ±0.026 pixels and ±0.024m for coordinates and stellar magnitudes respectively. To evaluate the repeatability of the scanner’s astrometric and photometric errors, six consecutive scans of one plate were processed with a spatial separation of 1200 dpi. The following error estimations are obtained for stars brighter than U< 13.5m: σxy = ±0.021 to 0.027 pixels and σm = ±0.014m to 0.016m for rectangular coordinates and instrumental stellar magnitudes respectively.

COMPARISON OF ZERO ZONE CATALOGUES OF THE FON PROGRAM BASED ON THE KYIV AND KITAB OBSERVATIONS

The two new catalogues for the zero zone of the FON project were created after the processing of two different collections of digitized photographic plates. The photographic plates were received at the DAZ and DWA telescopes of the Kitab observatory of the Republic of Uzbekistan (KO UAS) and of the Main astronomical observatory in Kyiv (MAO NASU) in the number of 90 and 120 plates, respectively. The digitization of these photographic plates in the frame of the Ukrainian Virtual Observatory project was performed by means of the Epson Expression 10000XL scanner with the scanning resolution of 1200 dpi. The coordinates of stars and galaxies for the both catalogues are determined in the system of the Tycho2 catalogue. The stellar magnitudes of all objects are done in B-magnitudes of the photoelectric standard system. The difference between the calculated and the reference positions is equal σαδ = ±0.06–0.07". The internal accuracy of the both catalogues for all objects is σ αδ = ±0.20", σB = ±0.18m and σ αδ = ±0.27", σ B = ±0.17m, respectively. We present the comparison of these both catalogues with each other and with the Tycho2, UCAC4 as well as PPMX catalogues and discuss the results.

Correlation analysis between the rate of respiration in the root and the active components in licorice (Glycyrrhiza uralensis)

The aim of this study was to investigate the correlation between root respiration and the percentage of active components in licorice (Glycyrrhiza uralensis Fisch.), in order to provide a foundation for the regulation and modulation of the quality of G. uralensis. Respiration efflux of annual and biennial G. uralensis was determined using a Li-7000 CO2/H2O analyzer. The root systems were scanned at a resolution of 3,000 dpi using an Epson Expression 10000XL scanner. Root growth was determined by analyzing the scanned images using WinRHIZO version Pro2007d software and the rate of respiration in the root was subsequently calculated. In addition, the percentages of the five major active components in licorice, glycyrrhizic acid, glycyrrhizin, isoliquiritin, liquiritigenin and isoliquiritigenin, were detected using high-performance liquid chromatography (HPLC). The correlation between the root respiration and the percentage of the active components was investigated. Significant seasonal changes were observed in the rates of respiration of first and zero-class roots. In annual and biennial G. uralensis, the maximum and minimum values for rate of respiration were present in July (P<0.05) and November (P<0.05), respectively. The correlation coefficients between the five major active components and the rate of respiration were −0.304 (glycyrrhizin), −0.129 (liquiritigenin), −0.441 (glycyrrhizic acid; P<0.05), −0.471 (isoliquiritin; P<0.05) and 0.148 (isoliquiritigenin). The percentages of glycyrrhizic acid and isoliquiritin were significantly negatively correlated with the rate of respiration in annual and biennial G. uralensis. Understanding the correlation between the root rate of respiration and the active components in G. uralensis may be beneficial to ensuring the quality of cultivated G. uralensis.

SU-E-T-79: Study On the Effective Depth of Measurement for Gafchromic EBT2 and EBT3 Films

Purpose: To determine the effective depth of measurement for Gafchromic EBT2 and EBT3 filmsMethods: Absolute dose point measurements were made with EBT2 and EBT3 film on the surface of flat phantom and at various depths. The films were cut to an approx. 1–2 mm square size and placed on the beam central axis. Measurements with an Exradin A1SL ion chamber were performed for each irradiation. A dose of 1 Gy was delivered to Dmax=1.5 cm. A previously validated Monte Carlo (MC) model was used for simulation and comparison to measurements. The MC simulation data was collected at 0.1 mm steps along the beam central axis. Film measurements were converted to dose using a post-irradiation signal consisting of the red and blue color channels from an Epson Expression 10000XL scanner. Film analysis was performed using ImageJ software and MATLAB. Measurements were converted to PDD and then compared to MC data to determine an effective depth of film measurement. Results: EBT2 measurements showed a systematic upstream shift of 0.10 mm with respect to the MC data while EBT3 showed the shift to be slightly less at 0.07 mm. The error in film measurement was estimated to be 0.04 mm (2σ). All measurements were within one STD of the MC error of 0.33 mm. Conclusion: The PDD measurements of EBT2 and EBT3 were consistent amongst themselves and agreement with MC was excellent. The observed shift in the results and the measurement error are smaller than the error in MC data, a possible indication that the nominal depth of measurement can be considered as the effective depth of measurement. A study with more accurate geometry for comparison is needed to determine a conclusive depth of measurement.

Poster - Thur Eve - 18: Characterization of a camera and LED lightbox imaging system for radiochromic film dosimetry.

Radiation therapy treatment modalities continue to develop and have become increasingly complex. With this, dose verification and quality assurance (QA) is of great importance to ensure that a prescribed dose is accurately and precisely delivered to a patient. Radiochromic film dosimetry has been adopted as a convenient option for QA, because it is relatively energy independent, is near tissue equivalent, and has high spatial resolution. Unfortunately, it is not always easy to use. In this study, preliminary work towards developing a novel method of imaging radiochromic film is presented. The setup consists of a camera mounted vertically above a lightbox containing red LEDs, interfaced with computer image acquisition software. Imaging results from this system will be compared with imaging performed using an Epson Expression 10000XL scanner (a device in common clinical use). The lightbox imaging technique with camera readout is much faster relative to a flatbed scanner. The film measurements made using the camera are independent of film orientation, and show reduced artifacts, so that there are fewer corrections required compared to the use of flatbed scanners. Optical scatter also appears to be less of an issue with this design than with the flat bed scanner. While further work needs to be done to optimize the lightbox imaging system, the lightbox system shows great promise for a rapid, simple, and orientation independent setup, improving on existing film scanning systems.

A comparison between radiochromic EBT2 film model and its predecessor EBT film model

The manufacturer has introduced the new EBT2 film model so as to improve its predecessor, the EBT radiochromic film model. According to the manufacturer, some of its main advantages include a higher tolerance to light exposure and it can correct non-uniformity of the active layer thickness using a marker dye. However, the equivalence in uniformity between both models was questioned by some authors, and the asymmetrical configuration of layers of the EBT2 film model produces a new dependence on the film side being scanned (front and back orientation). In this study, the EBT2 radiochromic film model was compared with the EBT model and the new marker dye feature was assessed. We also compared this correction method with a pre-irradiated pixel value correction method. An Epson Expression 10000XL scanner in transmission mode was used to scan the films and the red channel response was analyzed. We confirmed the lower-measured signal dependence on the visible light exposure of the EBT2 film model. Differences in pixel values remained below 0.5% for a minimum of 15 days. In regard to the uniformity, similar results for EBT2 and EBT film models were obtained; in both cases inhomogeneity was found to be less than 1%, in relative pixel value from the mean. However, we found that the signal-to-noise ratio was reduced for low doses by 37% for old EBT2 batch and by 21% for new EBT2 batch compared to signal-to-noise ratio for EBT. The EBT2 film model's pixel value difference for the front and back orientation reached up to 1.0% in the red channel. Our results did not show a clear advantage between to use a pre-irradiated pixel value correction and to use the manufacturer's correction.

SU-D-BRCD-04: Validation of Film Dosimetry in the Dose Build-Up Region.

To establish a film dosimetric method for high-resolution measurement in the dose build-up region. Percent depth dose (PDD) curves were measured in water for TomoTherapy using Gafchromic EBT2 films. Depth dose measurements were also performed using Standard Imaging A1SL and PTW PinPoint ionization chambers, as well as a PTW DiodeE detector. The film and detector measurements were then compared to Monte Carlo (MC) simulation data computed using PENELOPE. An in- house support apparatus was constructed to hold the films parallel to the beam central axis while being suspended in the water, simultaneously demarcating the water surface on the film. The films were converted to dose using a corrected net optical density method involving the red and blue color channels of an Epson Expression 10000XL scanner. Film analysis was performed using ImageJ software and MATLAB code developed in clinic. In our film method, a systematic shift of 1.2mm downstream is seen for the sample of five films, with good reproducibility within the sample (s=0.3mm). The film measurements showed a mean PDD difference of 0.3% (s=0.4%) with a maximum of 1.3% from that of MC between depths of 0.5mm to 20mm. The average film dose measured at the water surface (d=0mm) was 13.1% greater than that calculated by MC. EBT2 film shows much better agreement with MC in the dose build-up region than the ionization chamber and detector measurements. This study demonstrates the capability of EBT2 films for simple and accurate superficial dose measurements. A suspected reason for the systematic shift in film alignment is attributed to difficulty in determining water surface due to the meniscus that forms at the film. Funded by SSRMP Research Grant 2011.

High‐precision GAFCHROMIC EBT film‐based absolute clinical dosimetry using a standard flatbed scanner without the use of a scanner non‐uniformity correction

To report a study of the use of GAFCHROMIC EBT radiochromic film (RCF) digitized with a commercially available flatbed document scanner for accurate and reliable all‐purpose two‐dimensional (2D) absolute dosimetry within a clinical environment. We used a simplified methodology that yields high‐precision dosimetry measurements without significant postirradiation correction. The Epson Expression 1680 Professional scanner and the Epson Expression 10000XL scanner were used to digitize the films. Both scanners were retrofitted with light‐diffusing glass to minimize the effects of Newton rings. Known doses were delivered to calibration films. Flat and wedge fields were irradiated with variable depth of solid water and 5 cm back scatter solid water. No particular scanner nonuniformity effect corrections or significant post‐scan image processing were carried out. The profiles were compared with CC04 ionization chamber profiles. The depth dose distribution was measured at a source‐to‐surface distance (SSD) of 100 cm with a field size of 10×10 cm2. Additionally, 22 IMRT fields were measured and evaluated using gamma index analysis. The overall accuracy of RCF with respect to CC04 was found to be 2%–4%. The overall accuracy of RCF was determined using the absolute mean of difference for all flat and wedge field profiles. For clinical IMRT fields, both scanners showed an overall gamma index passing rate greater than 90%. This work demonstrated that EBT films, in conjunction with a commercially available flatbed scanner, can be used as an accurate and precise absolute dosimeter. Both scanners showed that no significant scanner nonuniformity correction is necessary for accurate absolute dosimetry using the EBT films for field sizes smaller than or equal to 15×15 cm2.PACS number: 87.53.Bn

Evaluation of an Epson flatbed scanner to read Gafchromic EBT films for radiation dosimetry

Gafchromic EBT (EBT) films are becoming increasingly popular due to their advantageous properties. When flatbed colour scanners are used for film dosimetry, a good quality control of the scanning device is a crucial step for accurate results. The proposal of this work was to fully assess the performance of the scanner Epson Expression 10000XL in order to quantify all parameters and needed corrections to minimize dose uncertainties. A standard step tablet, with 32 steps and optical densities from 0.06 to 3.8, was used to check the scanner linearity. The scanner warming-up effect and reproducibility were evaluated by performing 30 consecutive scans plus 20 scans in 15 min intervals. The scanning colour modes: 24 and 48 bits and scanning resolutions from 50 to 300 dpi were tested. A Wiener filter with different pixels regions was applied with the purpose of reducing the film noise. All scans were made in transmission mode with a constant film orientation. The red colour channel was posteriorly extracted from the images to maximize readout sensitivity. Two EBT films were irradiated, perpendicularly and parallel to beam incidence, with a 6 MV photon beam with doses that ranged from 0.2 to 3 Gy. A polynomial expression was used to convert optical density into dose. Dose uncertainty was quantified applying error propagation analysis. A correction for the non-uniform response of the scanner was determined using five films irradiated with a uniform dose. The scanner response was linear until an optical density of approximately 1 which corresponds to doses higher than those of clinical interest for EBT films. The scanner signal stabilized after seven readings. Scanner reproducibility around 0.2% was obtained either with the scanner warm or cold. However, reproducibility was significantly reduced when comparing images digitized with the scanner at different temperatures. Neither the colour depth mode, the scanning resolution, the multiscan option nor the Wiener filter had a significant effect on the shape of the calibration curve. However, a reduction in dose uncertainty was possible by selecting appropriate reading parameters. These are a 48 bit colour depth, a 75 dpi resolution and repeating the scan four times. Finally, the two dimensional Wiener filter applied to a 3 × 3 pixel region to the red component of the image reduced the experimental scan uncertainty to about 0.5% for doses higher than 0.5 Gy. Total scan uncertainty was less than 2% for a perpendicular calibration and reduced to less than 1% for a parallel calibration. A dose over-estimation of around 5% for clinical doses may be made if the image acquired is not corrected for the non-uniform response of the scanner. A protocol to read EBT films using the Epson Expression 10000XL scanner was established for IMRT verification. The contribution for the overall uncertainty in film dosimetry coming from the scanning process was estimated to be around 0.5% for doses higher than 0.5 Gy when reading parameters are optimized. Total scan uncertainty achieved is about 2% when using a perpendicular calibration. It can further be reduced if a parallel calibration is used.