Optical flow based image analysis for investigating failure mechanism of a rock sample

2013 ◽  
pp. 251-256
Author(s):  
S Bhattacharjee ◽  
D Deb
Keyword(s):  
Image Analysis ◽  
Optical Flow ◽  
Failure Mechanism ◽  
Rock Sample

Visualization by P-flow: gradient- and feature-based optical flow and vector fields extracted from image analysis

2020 ◽  
Vol 37 (12) ◽  
pp. 1958
Author(s):  
Wataru Suzuki ◽  
Atsushi Hiyama ◽  
Noritaka Ichinohe ◽  
Wakayo Yamashita ◽  
Takeharu Seno ◽  
...  
Keyword(s):  
Image Analysis ◽  
Optical Flow ◽  
Vector Fields ◽  
Flow Gradient ◽  
Feature Based

scholarly journals VELOCITY FIELD COMPUTATION IN VIBRATED GRANULAR MEDIA USING AN OPTICAL FLOW BASED MULTISCALE IMAGE ANALYSIS METHOD

2011 ◽  
Vol 28 (1) ◽  
pp. 35 ◽  
Author(s):  
Johan Debayle ◽  
Ahmed Raihane ◽  
Abdelkrim Belhaoua ◽  
Olivier Bonnefoy ◽  
Gérard Thomas ◽  
...  
Keyword(s):  
Image Analysis ◽  
Velocity Field ◽  
Optical Flow ◽  
Granular Media ◽  
Computation Time ◽  
Differential Method ◽  
Optical Observations ◽  
Motion Field ◽  
Analysis Method ◽  
Image Analysis Method

An image analysis method has been developed in order to compute the velocity field of a granular medium (sand grains, mean diameter 600 μm) submitted to different kinds of mechanical stresses. The differential method based on optical flow conservation consists in describing a dense motion field with vectors associated to each pixel. A multiscale, coarse-to-fine, analytical approach through tailor sized windows yields the best compromise between accuracy and robustness of the results, while enabling an acceptable computation time. The corresponding algorithmis presented and its validation discussed through different tests. The results of the validation tests of the proposed approach show that the method is satisfactory when attributing specific values to parameters in association with the size of the image analysis window. An application in the case of vibrated sand has been studied. An instrumented laboratory device provides sinusoidal vibrations and enables external optical observations of sand motion in 3D transparent boxes. At 50 Hz, by increasing the relative acceleration G, the onset and development of two convective rolls can be observed. An ultra fast camera records the grain avalanches, and several pairs of images are analysed by the proposed method. The vertical velocity profiles are deduced and allow to precisely quantify the dimensions of the fluidized region as a function of G.

Improved algorithm for motion image analysis based on optical flow and its application

2011 ◽  
Vol 19 (5) ◽  
pp. 1159-1164 ◽  
Author(s):  
屠大维 TU Da-wei ◽  
江济良 JIANG Ji-liang
Keyword(s):  
Image Analysis ◽  
Optical Flow ◽  
Improved Algorithm

Automated Image Analysis Of Nuclear And Cytoplasmic Changes In Exfoliated Cells From Tracheas Treated With Carcinogen

1977 ◽  
Vol 35 ◽  
pp. 220-221
Author(s):  
S.F. Stinson ◽  
J.C. Lilga ◽  
M.B. Sporn
Keyword(s):  
Image Analysis ◽  
Pattern Analysis ◽  
Relative Proportion ◽  
Automated Image Analysis ◽  
Image Analyzer ◽  
Cross Sectional ◽  
Exfoliated Cells ◽  
Neoplastic Lesions ◽  
Analysis System ◽  
Morphologic Criterion

Increased nuclear size, resulting in an increase in the relative proportion of nuclear to cytoplasmic sizes, is an important morphologic criterion for the evaluation of neoplastic and pre-neoplastic cells. This paper describes investigations into the suitability of automated image analysis for quantitating changes in nuclear and cytoplasmic cross-sectional areas in exfoliated cells from tracheas treated with carcinogen.Neoplastic and pre-neoplastic lesions were induced in the tracheas of Syrian hamsters with the carcinogen N-methyl-N-nitrosourea. Cytology samples were collected intra-tracheally with a specially designed catheter (1) and stained by a modified Papanicolaou technique. Three cytology specimens were selected from animals with normal tracheas, 3 from animals with dysplastic changes, and 3 from animals with epidermoid carcinoma. One hundred randomly selected cells on each slide were analyzed with a Bausch and Lomb Pattern Analysis System automated image analyzer.

Progress In The Practical Application Of Automated Image Analysis To Tem Negatives

1977 ◽  
Vol 35 ◽  
pp. 214-217
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly
Keyword(s):  
Image Analysis ◽  
Image Quality ◽  
Exposure Time ◽  
Image Contrast ◽  
Automated Image Analysis ◽  
Practical Application ◽  
Factors Affecting ◽  
High Image Quality ◽  
Qualitative Evidence ◽  
Comprehensive Study

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

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