scholarly journals Hyperspectral characterisation of natural illumination in woodland and forest environments

2021 ◽  
Author(s):  
Li Shiwen ◽  
Laura Steel ◽  
Cecilia A. L. Dahlsjö ◽  
Stuart N. Peirson ◽  
Alexander Shenkin ◽  
...  
Keyword(s):  
Image Processing ◽  
Dynamic Range ◽  
Imaging System ◽  
High Dynamic Range ◽  
Light Environment ◽  
Imaging Method ◽  
Specular Reflectance ◽  
Processing Pipeline ◽  
Spatially Resolved ◽  
Spectrally Resolved

Light in nature is complex and dynamic, and varies along spectrum, space, direction, and time. While both spectrally resolved measurements and spatially resolved measurements are widely available, spectrally and spatially resolved measurements are technologically more challenging. Here, we present a portable imaging system using off-the-shelf components to capture the full spherical light environment in a spectrally and spatially resolved fashion. The method relies on imaging the 4π-steradian light field reflected from a mirrored chrome sphere using a commercial hyperspectral camera (400-1000 nm) from multiple directions and an image-processing pipeline for extraction of the mirror sphere, removal of saturated pixels, correction of specular reflectance of the sphere, promotion to a high dynamic range, correction of misalignment of images, correction of intensity compression, erasure of the imaging system, unwrapping of the spherical images, filling-in blank regions, and stitching images collected from different angles. We applied our method to Wytham Woods, an ancient semi-natural woodland near Oxford, UK. We acquired a total of 168 images in two sites with low and high abundance of ash, leading to differences in canopy, leading to a total 14 hyperspectral light probes. Our image-processing pipeline corrected small (<3 deg) field-based misalignment adequately. Our novel hyperspectral imaging method is adapted for field conditions and opens up novel opportunities for capturing the complex and dynamic nature of the light environment.

scholarly journals Image processing pipeline for segmentation and material classification based on multispectral high dynamic range polarimetric images

2017 ◽  
Vol 25 (24) ◽  
pp. 30073 ◽  
Author(s):  
Miguel Ángel Martínez-Domingo ◽  
Eva M. Valero ◽  
Javier Hernández-Andrés ◽  
Shoji Tominaga ◽  
Takahiko Horiuchi ◽  
...  
Keyword(s):  
Image Processing ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Processing Pipeline ◽  
Material Classification ◽  
High Dynamic

scholarly journals Performance assessment of imaging plates for the JHR transfer Neutron Imaging System

2018 ◽  
Vol 170 ◽  
pp. 04021
Author(s):  
E. Simon ◽  
P. Guimbal
Keyword(s):  
Performance Assessment ◽  
Dynamic Range ◽  
Imaging System ◽  
Computed Radiography ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Neutron Imaging ◽  
Imaging Plate ◽  
Intimate Contact ◽  
Imaging Plates

The underwater Neutron Imaging System to be installed in the Jules Horowitz Reactor (JHR-NIS) is based on a transfer method using a neutron activated beta-emitter like Dysprosium. The information stored in the converter is to be offline transferred on a specific imaging system, still to be defined. Solutions are currently under investigation for the JHR-NIS in order to anticipate the disappearance of radiographic films commonly used in these applications. We report here the performance assessment of Computed Radiography imagers (Imaging Plates) performed at LLB/Orphée (CEA Saclay). Several imaging plate types are studied, in one hand in the configuration involving an intimate contact with an activated dysprosium foil converter: Fuji BAS-TR, Fuji UR-1 and Carestream Flex XL Blue imaging plates, and in the other hand by using a prototypal imaging plate doped with dysprosium and thus not needing any contact with a separate converter foil. The results for these imaging plates are compared with those obtained with gadolinium doped imaging plate used in direct neutron imaging (Fuji BAS-ND). The detection performances of the different imagers are compared regarding resolution and noise. The many advantages of using imaging plates over radiographic films (high sensitivity, linear response, high dynamic range) could palliate its lower intrinsic resolution.

scholarly journals Anti-Shake HDR Imaging Using RAW Image Data

Information ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 213 ◽  
Author(s):  
Yan Liu ◽  
Bingxue Lv ◽  
Wei Huang ◽  
Baohua Jin ◽  
Canlin Li
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Image Sensor ◽  
Image Sequences ◽  
Reference Image ◽  
Imaging Method ◽  
Camera Motion ◽  
Range Image ◽  
Real Scene ◽  
High Dynamic

Camera shaking and object movement can cause the output images to suffer from blurring, noise, and other artifacts, leading to poor image quality and low dynamic range. Raw images contain minimally processed data from the image sensor compared with JPEG images. In this paper, an anti-shake high-dynamic-range imaging method is presented. This method is more robust to camera motion than previous techniques. An algorithm based on information entropy is employed to choose a reference image from the raw image sequence. To further improve the robustness of the proposed method, the Oriented FAST and Rotated BRIEF (ORB) algorithm is adopted to register the inputs, and a simple Laplacian pyramid fusion method is implanted to generate the high-dynamic-range image. Additionally, a large dataset with 435 various exposure image sequences is collected, which includes the corresponding JPEG image sequences to test the effectiveness of the proposed method. The experimental results illustrate that the proposed method achieves better performance in terms of anti-shake ability and preserves more details for real scene images than traditional algorithms. Furthermore, the proposed method is suitable for extreme-exposure image pairs, which can be applied to binocular vision systems to acquire high-quality real scene images, and has a lower algorithm complexity than deep learning-based fusion methods.

scholarly journals A High-Dynamic-Range Optical Remote Sensing Imaging Method for Digital TDI CMOS

2017 ◽  
Vol 7 (10) ◽  
pp. 1089 ◽  
Author(s):  
Taiji Lan ◽  
Xucheng Xue ◽  
Junlin Li ◽  
Chengshan Han ◽  
Kehui Long
Keyword(s):  
Remote Sensing ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Imaging Method ◽  
Optical Remote Sensing ◽  
High Dynamic

scholarly journals Photometric image processing for high dynamic range displays

2007 ◽  
Vol 18 (5) ◽  
pp. 439-451 ◽  
Author(s):  
Matthew Trentacoste ◽  
Wolfgang Heidrich ◽  
Lorne Whitehead ◽  
Helge Seetzen ◽  
Greg Ward
Keyword(s):  
Image Processing ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
High Dynamic

scholarly journals ANALISA CITRA HIPERSPEKTRAL DAUN DARI TANAMAN KELAPA SAWIT YANG MENGALAMI KEKURANGAN AIR MENGGUNAKAN PROGRAM MATLAB

2019 ◽  
Vol 16 (2) ◽  
pp. 143
Author(s):  
JR Lessy Eka Putri ◽  
Minarni Minarni ◽  
Feri Candra ◽  
Herman Herman
Keyword(s):  
Image Processing ◽  
Hyperspectral Imaging ◽  
Oil Palm ◽  
Imaging System ◽  
Water Volume ◽  
Imaging Method ◽  
Pixel Size ◽  
Water Deficiency ◽  
Image Recording ◽  
Detached Leaves

The hyperspectral imaging method has been widely and intensively used in agriculture to find out various problems that occur in plants. Image processing is very important step in an imaging method. This research aims to create Matlab based program to be used to analyze the leaf image of oil palm plants that has experienced water deficiency. Reflectance intensity values were extracted from the process. The hyperspectral imaging system consisted of a 650 nm diode laser, a spectrograph, monochrome CMOS camera, and Matlab image processing program. The samplesused were 8 month old Tenera variety of oil palm seedlings which were treated to simulate water deficiency in the form of variations in the volume of water, namely 0 mL (without watering), 1000 mL, 2000 mL, and 3000 mL (normal), 3 duplicates for each volume. The samples were given water volume of 1000 mL and 2000 mL for every 7 days in 21 days, while the sampleswith 3000 mL of water were watered every day. Image recording was done on the 21st day for detached leaves at the the bottom part.The results showed that the Matlab program was able to separate each row from 15 images, each of which had a pixel size of 1280 × 1024 and merge each of the same lines into 1024 images with a pixel size of 1280 × 15. The reflectance intensity values were then obtained. The results showed that higher levels of water deficiency in plants produce increasing reflectance intensity values.

scholarly journals Characterization of online high dynamic range imaging for laser-driven ion beam diagnostics using visible light

2017 ◽  
Vol 3 (2) ◽  
pp. 343-346
Author(s):  
Franz Englbrecht ◽  
Felix Balling ◽  
Thomas Federico Rösch ◽  
Matthias Würl ◽  
Florian Hans Lindner ◽  
...  
Keyword(s):  
Spatial Information ◽  
Dynamic Range ◽  
Ion Beam ◽  
Complementary Metal Oxide Semiconductor ◽  
Laser Pulses ◽  
High Dynamic Range ◽  
Oxide Semiconductor ◽  
Beam Diagnostics ◽  
Spatially Resolved ◽  
Single Frame

AbstractLaser-driven acceleration of particle beams is an emerging modality under research for biomedical applications. The spatially resolved diagnostics of laser-accelerated proton bunches is crucial for their application. The RadEye detector, featuring up to 10 cm x 5 cm area of online complementary metal-oxide-semiconductor (CMOS) detector made of 48 μm pixels, is established for x-ray, proton and ion beam diagnostics. We exploit the usually undesired ‘Image lag’ phenomenon of incomplete pixel reset to generate 2D-images with a larger dynamic range than the single frame range of 12-bit. Using 532 nm laser pulses and computer simulations for single-slit diffraction, calibration factors to stack multiple readouts were successfully derived to quantitatively reconstruct spatial information about an optical beam and hence extend the dynamic range of the detector compared to a single frame. The final goal is focus quantification for a permanent magnet quadrupole system for protons and terawatt (TW-class) laser focus diagnostics.

Sign in / Sign up

Export Citation Format

Share Document