scholarly journals Performance Evaluation of Dorsal Vein Network of Hand Imaging Using Relative Total Variation-Based Regularization for Smoothing Technique in a Miniaturized Vein Imaging System: A Pilot Study

2021 ◽  
Vol 18 (4) ◽  
pp. 1548 ◽  
Author(s):  
Kyuseok Kim ◽  
Hyun-Woo Jeong ◽  
Youngjin Lee
Keyword(s):  
Image Quality ◽  
Total Variation ◽  
Near Infrared ◽  
Imaging System ◽  
Histogram Equalization ◽  
Evaluation Performance ◽  
Visual Evaluation ◽  
Évaluation Performance ◽  
Nir Imaging ◽  
Relative Total Variation

Vein puncture is commonly used for blood sampling, and accurately locating the blood vessel is an important challenge in the field of diagnostic tests. Imaging systems based on near-infrared (NIR) light are widely used for accurate human vein puncture. In particular, segmentation of a region of interest using the obtained NIR image is an important field, and research for improving the image quality by removing noise and enhancing the image contrast is being widely conducted. In this paper, we propose an effective model in which the relative total variation (RTV) regularization algorithm and contrast-limited adaptive histogram equalization (CLAHE) are combined, whereby some major edge information can be better preserved. In our previous study, we developed a miniaturized NIR imaging system using light with a wavelength of 720–1100 nm. We evaluated the usefulness of the proposed algorithm by applying it to images acquired by the developed NIR imaging system. Compared with the conventional algorithm, when the proposed method was applied to the NIR image, the visual evaluation performance and quantitative evaluation performance were enhanced. In particular, when the proposed algorithm was applied, the coefficient of variation was improved by a factor of 15.77 compared with the basic image. The main advantages of our algorithm are the high noise reduction efficiency, which is beneficial for reducing the amount of undesirable information, and better contrast. In conclusion, the applicability and usefulness of the algorithm combining the RTV approach and CLAHE for NIR images were demonstrated, and the proposed model can achieve a high image quality.

scholarly journals Near-infrared imaging of brain tumors using the Tumor Paint BLZ-100 to achieve near-complete resection of brain tumors

2014 ◽  
Vol 36 (2) ◽  
pp. E1 ◽  
Author(s):  
Pramod V. Butte ◽  
Adam Mamelak ◽  
Julia Parrish-Novak ◽  
Doniel Drazin ◽  
Faris Shweikeh ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Imaging System ◽  
Signal To Noise Ratio ◽  
Ccd Camera ◽  
Complete Resection ◽  
Human Glioma ◽  
Nir Imaging ◽  
The Brain

Object The intraoperative clear delineation between brain tumor and normal tissue in real time is required to ensure near-complete resection without damaging the nearby eloquent brain. Tumor Paint BLZ-100, a tumor ligand chlorotoxin (CTX) conjugated to indocyanine green (ICG), has shown potential to be a targeted contrast agent. There are many infrared imaging systems in use, but they are not optimized to the low concentration and amount of ICG. The authors present a novel proof-of-concept near-infrared (NIR) imaging system using a standard charge-coupled device (CCD) camera for visualizing low levels of ICG attached to the tumors. This system is small, inexpensive, and sensitive. The imaging system uses a narrow-band laser at 785 nm and a notch filter in front of the sensor at the band. The camera is a 2-CCD camera, which uses identical CCDs for both visible and NIR light. Methods The NIR system is tested with serial dilution of BLZ-100 from 1 μM to 50 pM in 5% Intralipid solution while the excitation energy is varied from 5 to 40 mW/cm2. The analog gain of the CCD was changed from 0, 6, and 12 dB to determine the signal-to-noise ratio. In addition to the Intralipid solution, BLZ-100 was injected 48 hours before euthanizing the mice that were implanted with the human glioma cell line. The brain was removed and imaged using the NIR imaging system. Results The authors' results show that the NIR imaging system using a standard CCD is able to visualize the ICG down to 50 nM of concentration with a high signal-to-noise ratio. The preliminary experiment on human glioma implanted in mouse brains demonstrated that BLZ-100 has a high affinity for glioma compared with normal brain tissue. Additionally, the results show that NIR excitation is able to penetrate deeply and has a potential to visualize metastatic lesions that are separate from the main tumor. Conclusions The authors have seen that BLZ-100 has a very high affinity toward human gliomas. They also describe a small, cost-effective, and sensitive NIR system for visualizing brain tumors tagged using BLZ-100. The authors hope that the use of BLZ-100 along with NIR imaging will be useful to delineate the brain tumors in real time and assist surgeons in near-complete tumor removal to increase survival and reduce neurological deficits.

scholarly journals Compressed Sensing Inspired Image Reconstruction from Overlapped Projections

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Lin Yang ◽  
Yang Lu ◽  
Ge Wang
Keyword(s):  
Image Reconstruction ◽  
Image Quality ◽  
Compressed Sensing ◽  
Total Variation ◽  
Linear Form ◽  
Imaging System ◽  
Initial Guess ◽  
Filtered Backprojection ◽  
Numerical Tests ◽  
Data Acquisition Process

The key idea discussed in this paper is to reconstruct an image from overlapped projections so that the data acquisition process can be shortened while the image quality remains essentially uncompromised. To perform image reconstruction from overlapped projections, the conventional reconstruction approach (e.g., filtered backprojection (FBP) algorithms) cannot be directly used because of two problems. First, overlapped projections represent an imaging system in terms of summed exponentials, which cannot be transformed into a linear form. Second, the overlapped measurement carries less information than the traditional line integrals. To meet these challenges, we propose a compressive sensing-(CS-) based iterative algorithm for reconstruction from overlapped data. This algorithm starts with a good initial guess, relies on adaptive linearization, and minimizes the total variation (TV). Then, we demonstrated the feasibility of this algorithm in numerical tests.

An Application for the Quantitative Analysis of Pharmaceutical Tablets Using a Rapid Switching System Between a Near-Infrared Spectrometer and a Portable Near-Infrared Imaging System Equipped with Fiber Optics

2018 ◽  
Vol 72 (4) ◽  
pp. 551-561 ◽  
Author(s):  
Kodai Murayama ◽  
Daitaro Ishikawa ◽  
Takuma Genkawa ◽  
Yukihiro Ozaki
Keyword(s):  
Ascorbic Acid ◽  
Near Infrared ◽  
Imaging System ◽  
Spot Size ◽  
Switching System ◽  
Pharmaceutical Tablets ◽  
Nir Imaging ◽  
Imaging Results ◽  
Rapid Switching ◽  
Mean Square Errors

We present a rapid switching system between a newly developed near-infrared (NIR) spectrometer and its imaging system to select the spot size of a diffuse reflectance (DR) probe. In a previous study, we developed a portable NIR imaging system, known as D-NIRs, which has significant advantages over other systems. Its high speed, high spectral resolution, and portability are particularly useful in the process of monitoring pharmaceutical tablets. However, the spectral accuracies relating to the changes in the formulation of the pharmaceutical tablets have not been fully discussed. Therefore, we improved the rapid optical switching system and present a new model of D-NIRs (ND-NIRs) here. This system can automatically switch the optical paths of the DR and NIR imaging probes, greatly contributing to the simultaneous measurement of both the imaging and spot. The NIR spectra of the model tablets, including 0–10% ascorbic acid, were measured and simultaneous NIR images of the tablets were obtained. The predicted results using spot sizes for the DR probe of 1 and 5 mm diameter, resulted in concentrations of R2 = 0.79 and 0.94, with root mean square errors (RMSE) of 1.78 and 0.89, respectively. For tablets with a high concentration of ascorbic acid, the NIR imaging results showed inhomogeneity in concentration. However, the predicted values for the low concentration samples appeared higher than the known concentration of the tablets, although the homogeneity of the concentration was confirmed. In addition, the optimal spot size using NIR imaging data was estimated to be 5–7 mm. The results obtained in this study show that the spot size of the fiber probe, attached to a spectrometer, is important in developing a highly reliable model to determine the component concentration of a tablet.

scholarly journals Learning to Measure Stereoscopic S3D Image Perceptual Quality on the Basis of Binocular Rivalry Response

2019 ◽  
Vol 9 (18) ◽  
pp. 3906
Author(s):  
Siyuan Huang ◽  
Wujie Zhou
Keyword(s):  
Image Quality ◽  
Binocular Rivalry ◽  
Quality Measurement ◽  
Research Field ◽  
Perceptual Quality ◽  
Evaluation Performance ◽  
Stereoscopic 3D ◽  
Performance Loss ◽  
Challenging Issue ◽  
Évaluation Performance

Blind perceptual quality measurement of stereoscopic 3D (S3D) images has become an important and challenging issue in the research field of S3D imaging. In this paper, a blind S3D image quality measurement (IQM) method that does not depend on examples of distorted S3D images and corresponding subjective scores is proposed. As the main contribution of this work, we replace human subjective scores with a quality codebook of binocular rivalry responses (BRRs); this allows blind S3D-IQM methods to be learned without evaluation performance loss. Our results, using the publicly accessible LIVE S3D dataset, confirm that our method is highly robust and efficient.

High-Speed Scanning for the Quantitative Evaluation of Glycogen Concentration in Bioethanol Feedstock Synechocystis sp. PCC6803 Using a Near-Infrared Hyperspectral Imaging System with a New Near-Infrared Spectral Camera

2016 ◽  
Vol 71 (3) ◽  
pp. 463-471 ◽  
Author(s):  
Mika Ishigaki ◽  
Akihito Nakanishi ◽  
Tomohisa Hasunuma ◽  
Akihiko Kondo ◽  
Tetsu Morishima ◽  
...  
Keyword(s):  
Quantitative Evaluation ◽  
High Speed ◽  
Near Infrared ◽  
Imaging System ◽  
Quantitative Estimation ◽  
Product Evaluation ◽  
Least Squares Regression ◽  
Glycogen Concentration ◽  
Nir Imaging ◽  
Synechocystis Sp

In the present study, the high-speed quantitative evaluation of glycogen concentration accumulated in bioethanol feedstock Synechocystis sp. PCC6803 was performed using a near-infrared (NIR) imaging system with a hyperspectral NIR spectral camera named Compovision. The NIR imaging system has a feature for high-speed and wide area monitoring and the two-dimensional scanning speed is almost 100 times faster than the general NIR imaging systems for the same pixel size. For the quantitative analysis of glycogen concentration, partial least squares regression (PLSR) and moving window PLSR (MWPLSR) were performed with the information of glycogen concentration measured by high performance liquid chromatography (HPLC) and the calibration curves for the concentration within the Synechocystis sp. PCC6803 cell were constructed. The results had high accuracy for the quantitative estimation of glycogen concentration as the best squared correlation coefficient R2 was bigger than 0.99 and a root mean square error (RMSE) was less than 2.9%. The present results proved not only the potential for the applicability of NIR spectroscopy to the high-speed quantitative evaluation of glycogen concentration in the bioethanol feedstock but also the expansivity of the NIR imaging instrument to in-line or on-line product evaluation on a factory production line of bioethanol in the future.

scholarly journals Revealing Hidden Features in Multilayered Artworks by Means of an Epi-Illumination Photoacoustic Imaging System

2021 ◽  
Vol 7 (9) ◽  
pp. 183
Author(s):  
George J. Tserevelakis ◽  
Antonina Chaban ◽  
Evgenia Klironomou ◽  
Kristalia Melessanaki ◽  
Jana Striova ◽  
...  
Keyword(s):  
Near Infrared ◽  
Imaging System ◽  
Photoacoustic Imaging ◽  
Structural Features ◽  
Thickness Measurement ◽  
Imaging Method ◽  
Nir Imaging ◽  
Wide Range ◽  
Detection Of Signals ◽  
Cultural Heritage Objects

Photoacoustic imaging is a novel, rapidly expanding technique, which has recently found several applications in artwork diagnostics, including the uncovering of hidden layers in paintings and multilayered documents, as well as the thickness measurement of optically turbid paint layers with high accuracy. However, thus far, all the presented photoacoustic-based imaging technologies dedicated to such measurements have been strictly limited to thin objects due to the detection of signals in transmission geometry. Unavoidably, this issue restricts seriously the applicability of the imaging method, hindering investigations over a wide range of cultural heritage objects with diverse geometrical and structural features. Here, we present an epi-illumination photoacoustic apparatus for diagnosis in heritage science, which integrates laser excitation and respective signal detection on one side, aiming to provide universal information in objects of arbitrary thickness and shape. To evaluate the capabilities of the developed system, we imaged thickly painted mock-ups, in an attempt to reveal hidden graphite layers covered by various optically turbid paints, and compared the measurements with standard near-infrared (NIR) imaging. The obtained results prove that photoacoustic signals reveal underlying sketches with up to 8 times improved contrast, thus paving the way for more relevant applications in the field.

scholarly journals Identification of Abnormal Biliary Anatomy Utilizing Real-Time Near-Infrared Cholangiography: A Report of Two Cases

2017 ◽  
Vol 2017 ◽  
pp. 1-4
Author(s):  
Joseph Bozzay ◽  
Diego Vicente ◽  
Elliot M. Jessie ◽  
Carlos J. Rodriguez
Keyword(s):  
Decision Making ◽  
Real Time ◽  
Near Infrared ◽  
Imaging System ◽  
Biliary Tree ◽  
Biliary Duct ◽  
Biliary Anatomy ◽  
Nir Imaging ◽  
Intraoperative Detection ◽  
Fluorescence Imaging System

Biliary duct anomalies are commonly encountered during laparoscopic cholecystectomy. Advancements in the field of surgery allow for enhanced intraoperative detection of these abnormalities. Fluorophore injection and near-infrared (NIR) imaging can provide real-time intraoperative anatomic feedback without intraoperative delays and ionizing radiation. This report details two cases where the PINPOINT Endoscopic Fluorescence Imaging System (NOVADAQ, Ontario, Canada) was used to identify anomalies of the biliary tree and guide operative decision-making.

Two-Dimensional Imaging of Water Vapor by Near-Infrared Laser Absorption Spectroscopy

2008 ◽  
Vol 62 (11) ◽  
pp. 1216-1220
Author(s):  
Shigeaki Morita ◽  
Eiji Hattori ◽  
Kuniyuki Kitagawa
Keyword(s):  
Water Vapor ◽  
Absorption Spectroscopy ◽  
Near Infrared ◽  
Imaging System ◽  
Wave Length ◽  
Two Dimensional ◽  
Laser Absorption Spectroscopy ◽  
Laser Absorption ◽  
Nir Imaging ◽  
2D Imaging

Both a flow of water vapor generated from a humidification device and stable water vapor at constant moisture were successfully visualized by near-infrared (NIR) laser absorption spectroscopy. Two different types of optical arrangement for two-dimensional (2D) imaging, i.e., one-wave-length reflection and two-wavelength transmission, were tested. A flow of water vapor within a wide view range was clearly visualized by the former, while low content of stable water vapor was quantitatively detected by the latter. It was demonstrated that a detection limit of 0.8 g·m−3 was achieved by means of the 2D-NIR imaging system developed in the present study.

Image Quality Enhancing by Efficient Histogram Equalization

2014 ◽  
Vol 2 (2) ◽  
pp. 47-58
Author(s):  
Ismail Sh. Baqer
Keyword(s):  
Image Quality ◽  
Contrast Enhancement ◽  
Mean Squared Error ◽  
Signal To Noise Ratio ◽  
Histogram Equalization ◽  
Gray Level ◽  
Signal To Noise ◽  
Squared Error ◽  
Noise Ratio

A two Level Image Quality enhancement is proposed in this paper. In the first level, Dualistic Sub-Image Histogram Equalization DSIHE method decomposes the original image into two sub-images based on median of original images. The second level deals with spikes shaped noise that may appear in the image after processing. We presents three methods of image enhancement GHE, LHE and proposed DSIHE that improve the visual quality of images. A comparative calculations is being carried out on above mentioned techniques to examine objective and subjective image quality parameters e.g. Peak Signal-to-Noise Ratio PSNR values, entropy H and mean squared error MSE to measure the quality of gray scale enhanced images. For handling gray-level images, convenient Histogram Equalization methods e.g. GHE and LHE tend to change the mean brightness of an image to middle level of the gray-level range limiting their appropriateness for contrast enhancement in consumer electronics such as TV monitors. The DSIHE methods seem to overcome this disadvantage as they tend to preserve both, the brightness and contrast enhancement. Experimental results show that the proposed technique gives better results in terms of Discrete Entropy, Signal to Noise ratio and Mean Squared Error values than the Global and Local histogram-based equalization methods

Sign in / Sign up

Export Citation Format

Share Document