2. Present Approaches to Measuring Image Quality Parameters

Author(s):  
P. Sharp ◽  
D. C. Barber ◽  
D. G. Brown ◽  
A. E. Burgess ◽  
C. E. Metz ◽  
...  
Author(s):  
Jiajia Guo ◽  
Kaizhi Wang ◽  
Yiran Jin ◽  
Xin Lin ◽  
Yesheng Gao ◽  
...  

Author(s):  
Miri Weiss Cohen ◽  
John A. Kennedy ◽  
Archil Pirmisashvili ◽  
Gleb Orlikov

This paper describes an automatic system for analyzing phantom images from two types of PET/CT scanners. The system was developed for the purpose of obtaining tomographic image quality parameters, which determine a number of different performance parameters, primarily scanner sensitivity, tomographic uniformity, contrast and spatial resolution. The system provides a method for generating and altering image masks used for the analysis of PET images, which are then automatically aligned with the PET data. The system automatically generates Quality Control (QC) reports and is currently being used at clinical PET/CT center.


2020 ◽  
Vol 10 (8) ◽  
pp. 2876 ◽  
Author(s):  
Bogdan Dugonik ◽  
Aleksandra Dugonik ◽  
Maruška Marovt ◽  
Marjan Golob

The fast-growing incidence of skin cancer, especially melanoma, is the guiding principle for intense development of various digital image-capturing devices providing easier recognition of melanoma by dermatologists. Handheld and digital dermoscopy, following of mole changes with smartphones and digital analysing of mole images, is based on evaluation of the colours, shape and deep structures in the skin moles. Incorrect colour information of an image, under- or overexposed images, lack of sharpness and low resolution of the images, can lead to melanoma misdiagnosis. The purpose of our study was to determine the colour error in the image according to the given lighting conditions and different camera settings. We focused on measuring the image quality parameters of smartphones and high-resolution cameras to compare them with the results of state-of-the-art dermoscopy device systems. We applied standardised measuring methods. The spatial frequency response method was applied for measuring the sharpness and resolution of the tested camera systems. Colour images with known reference values were captured from the test target, to evaluate colour error as a CIELAB (Commission Internationale de l’Eclairage) ΔE*ab colour difference as seen by a human observer. The results of our measurements yielded two significant findings. First, all tested cameras produced inaccurate colours when operating in automatic mode, and second, the amount of sharpening was too intensive. These deficiencies can be eliminated through adjusting the camera parameters manually or by image post-production. The presented two-step camera calibration procedure improves the colour accuracy of captured clinical and dermoscopy images significantly.


2011 ◽  
Vol 38 (6Part10) ◽  
pp. 3483-3483
Author(s):  
K Tournel ◽  
M Duchateau ◽  
T Reynders ◽  
T Gevaert ◽  
T Depuydt ◽  
...  

2020 ◽  
Vol 12 (24) ◽  
pp. 4029
Author(s):  
Sakib Kabir ◽  
Larry Leigh ◽  
Dennis Helder

Over the past decade, number of optical Earth-observing satellites performing remote sensing has increased substantially, dramatically increasing the capability to monitor the Earth. The quantity of remote sensing satellite increase is primarily driven by improved technology, miniaturization of components, reduced manufacturing, and launch cost. These satellites often lack on-board calibrators that a large satellite utilizes to ensure high quality (radiometric, geometric, spatial quality, etc.) scientific measurement. To address this issue, this work presents “best” vicarious image quality assessment and improvement techniques for those kinds of optical satellites which lack an on-board calibration system. In this article, image quality categories have been explored, and essential quality parameters (absolute and relative calibration, aliasing, etc.) have been identified. For each of the parameters, appropriate characterization methods are identified along with their specifications or requirements. In cases of multiple methods, recommendations have been made based-on the strengths and weaknesses of each method. Furthermore, processing steps have been presented, including examples. Essentially, this paper provides a comprehensive study of the criteria that need to be assessed to evaluate remote sensing satellite data quality, and the best vicarious methodologies to evaluate identified quality parameters such as coherent noise and ground sample distance.


2018 ◽  
Vol 08 (01) ◽  
pp. 37-44 ◽  
Author(s):  
Calvin Didier Njiki ◽  
Joseph Eric Martial Ndjaka Manyol ◽  
Yolande Ebele Yigbedeck ◽  
Daniel William Abou’ou ◽  
Blaise Clovis Yimele ◽  
...  

Author(s):  
Mateus Gesulado Carneiro De Santana ◽  
Guilherme Cavalcante de Albuquerque Souza ◽  
Rodrigo Modesto Gadelha Gontijo ◽  
Bruno Melo Mendes ◽  
Andréa Vidal Ferreira

LabPET GE 4 (a small animal positron emission tomograph) image acquisition is done by 1536 independents channels. Differences in the rate counting of each channel must be corrected so as not compromise image quality. Equipment user manual recommends that normalization of the detectors efficiency be made as often as possible and always whenever there are hardware or software parameters changes - included, but not limited to channels parameters adjustments, electronic cards replacements, channels activation or inactivation or software update. This work evaluates the normalization effects on the image quality parameters. PET image acquisition were performed using recommended parameters by the NEMA NU 4-2008 standards. Image was reconstructed in different ways using different normalization files. The tests performed indicated that the image quality parameters do not vary significantly with different normalization data. Therefore, a daily routine of normalizations is not justified, suggesting a periodical frequency of one month or more for this procedure.


Author(s):  
Nazila Saeidnezhad ◽  
Kunal Kumar ◽  
Bernhard H. Müller ◽  
Christoph Hoeschen ◽  
Oleg Tischenko

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