Metrics for measuring the impact of image processing algorithms on background statistics

2008 ◽  
Author(s):  
Patrick J. Harding ◽  
Gordon Arthur ◽  
Neil M. Robertson
2019 ◽  
Vol 64 ◽  
pp. 238-244
Author(s):  
I.A. Tsalafoutas ◽  
K. Kasviki ◽  
A. Samartzis ◽  
K. Trimmis ◽  
M.G. Gkeli

Author(s):  
B.A. Skorohod ◽  
◽  
P.V. Zhiyakov ◽  
A.V. Statsenko ◽  
S.I. Fateev ◽  
...  

Distortion of underwater images can impair both the accuracy and robustness of 3D scene reconstruction algorithms. The problems that arise are related to the lack of robustness of these methods to changes in the underwater environment and features of transmitting and receiving signals under water, including, in particular, uneven illumination of the underwater environment, rapid attenuation, scattering and refraction of light when passing through an inhomogeneous medium of air-water-glass, limiting the frequency spectrum of passing light, which leads to the absorption of low-frequency components to a greater extent than light of higher frequencies. All this seriously complicates the ability to extract information about the scene as a whole and objects of interest located in the underwater environment, limits the use of standard image processing algorithms and requires their significant improvement. This article offers a new approach to analyzing the accuracy of constructing 3D coordinates of the working space of an underwater robot. The approach is based on underwater camera calibration, assessment of camera image centers taking into account the waterproof shell. We use statistical analysis that allows us to evaluate the impact of all sources of disturbances (both hardware and software) based only on experimental data. In particular, it shows how to get the error distribution using the measured values of the calibration sample and obtained by triangulation under underwater conditions. This makes it possible to simultaneously evaluate the systematic error and the distribution characteristics of the random component of the error in restoring 3D coordinates of the workspace. An important feature of the proposed approach is the ability to assess the impact of all sources of disturbances in the aggregate, including the design of a waterproof shell, based only on experimental data obtained in the underwater environment. In addition, the same approach can also provide estimates of the position of camera image centers, allowing for the presence of a waterproof shell to improve the accuracy of image processing algorithms. The proposed approach was tested on real data.


Author(s):  
César D. Fermin ◽  
Dale Martin

Otoconia of higher vertebrates are interesting biological crystals that display the diffraction patterns of perfect crystals (e.g., calcite for birds and mammal) when intact, but fail to produce a regular crystallographic pattern when fixed. Image processing of the fixed crystal matrix, which resembles the organic templates of teeth and bone, failed to clarify a paradox of biomineralization described by Mann. Recently, we suggested that inner ear otoconia crystals contain growth plates that run in different directions, and that the arrangement of the plates may contribute to the turning angles seen at the hexagonal faces of the crystals.Using image processing algorithms described earlier, and Fourier Transform function (2FFT) of BioScan Optimas®, we evaluated the patterns in the packing of the otoconia fibrils of newly hatched chicks (Gallus domesticus) inner ears. Animals were fixed in situ by perfusion of 1% phosphotungstic acid (PTA) at room temperature through the left ventricle, after intraperitoneal Nembutal (35mg/Kg) deep anesthesia. Negatives were made with a Hitachi H-7100 TEM at 50K-400K magnifications. The negatives were then placed on a light box, where images were filtered and transferred to a 35 mm camera as described.


Fast track article for IS&T International Symposium on Electronic Imaging 2020: Image Processing: Algorithms and Systems proceedings.


Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 457
Author(s):  
Manuel Henriques ◽  
Duarte Valério ◽  
Paulo Gordo ◽  
Rui Melicio

Many image processing algorithms make use of derivatives. In such cases, fractional derivatives allow an extra degree of freedom, which can be used to obtain better results in applications such as edge detection. Published literature concentrates on grey-scale images; in this paper, algorithms of six fractional detectors for colour images are implemented, and their performance is illustrated. The algorithms are: Canny, Sobel, Roberts, Laplacian of Gaussian, CRONE, and fractional derivative.


Sign in / Sign up

Export Citation Format

Share Document