Influence of MRI acquisition protocols and image intensity normalization methods on texture classification

2004 ◽  
Vol 22 (1) ◽  
pp. 81-91 ◽  
Author(s):  
G. Collewet ◽  
M. Strzelecki ◽  
F. Mariette
Author(s):  
I Nyoman Gede Arya Astawa ◽  
I Ketut Gede Darma Putra ◽  
I Made Sudarma ◽  
Rukmi Sari Hartati

One of the factors that affects the detection system or face recognition is lighting. Image color processing can help the face recognition system in poor lighting conditions. In this study, homomorphic filtering and intensity normalization methods used to help improve the accuracy of face image detection. The experimental results show that the non-uniform of the illumination of the face image can be uniformed using the intensity normalization method with the average value of Peak Signal to Noise Ratio (PSNR) obtained from the whole experiment is 22.05314 and the average Absolute Mean Brightness Error (AMBE) value obtained is 6.147787. The results showed that homomorphic filtering and intensity normalization methods can be used to improve the detection accuracy of a face image.


PLoS ONE ◽  
2015 ◽  
Vol 10 (7) ◽  
pp. e0135107 ◽  
Author(s):  
A. Brahim ◽  
J. Ramírez ◽  
J. M. Górriz ◽  
L. Khedher ◽  
D. Salas-Gonzalez

2004 ◽  
Vol 26 (1-2) ◽  
pp. 31-43
Author(s):  
Martial Guillaud ◽  
Dennis Cox ◽  
Anais Malpica ◽  
Gregg Staerkel ◽  
Jasenka Matisic ◽  
...  

Objectives: As part a Program Project to evaluate emerging optical technologies for cervical neoplasia, our group is performing quantitative histopathological analysis of biopsies from 1800 patients. Several methodological issues have arisen with respect to this analysis: (1) Finding the most efficient way to compensate for staining intensity variation with out losing diagnostic information; (2) Assessing the inter‐ and intra‐observer variability of the semi‐interactive data collection; and (3) the use of non‐overlapping cells from the intermediate layer only. Methods: Non‐overlapping quantitatively stained nuclei were selected from 280 samples with histopathological characteristics of normal (199), koilocytosis (37), CIN 1 (18), CIN 2 (10) and CIN 3 (16). Linear discriminant analysis was used to assess the diagnostic information in three different feature sets to evaluate and compare staining intensity normalization methods. Selected feature values and summary scores were used to evaluate intra‐ and inter‐observer variability. Results: The features normalized by the internal subset of the imaged cells had the same discriminatory power as those normalized by the control cells and by both normalization methods seem to have additional discriminatory power over the set of features which do not require normalization. The use of the internal subset decreased the image acquisition time by ∼50% at each center, respectively. The intra‐ and inter‐observer variability was of a similar size. Good performance was obtained by measuring the intermediate layer only. Conclusion: The use of intensity normalization from a subset of the imaged non‐overlapping intermediate layer cells works as well as or better than any of the other methods tested and provides a significant timesaving. Our intra‐ and inter‐observer variability do not seem to affect the diagnostic power of the data. Although this must be tested in a larger data set, the use of intermediate layer cells only may be acceptable when using quantitative histopathology.


PROTEOMICS ◽  
2011 ◽  
Vol 11 (6) ◽  
pp. 1172-1180 ◽  
Author(s):  
Sven Degroeve ◽  
Niklaas Colaert ◽  
Joël Vandekerckhove ◽  
Kris Gevaert ◽  
Lennart Martens

PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0130274 ◽  
Author(s):  
A. Brahim ◽  
J. Ramírez ◽  
J. M. Górriz ◽  
L. Khedher ◽  
D. Salas-Gonzalez

2006 ◽  
Vol 14 (7S_Part_5) ◽  
pp. P318-P318
Author(s):  
Sepideh Shokouhi ◽  
Hakmook Kang ◽  
Harry E. Gwirtsman ◽  
Paul A. Newhouse

NeuroImage ◽  
2020 ◽  
Vol 222 ◽  
pp. 117229 ◽  
Author(s):  
Francisco J. López-González ◽  
Jesús Silva-Rodríguez ◽  
José Paredes-Pacheco ◽  
Aida Niñerola-Baizán ◽  
Nikos Efthimiou ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3000
Author(s):  
Yingping Li ◽  
Samy Ammari ◽  
Corinne Balleyguier ◽  
Nathalie Lassau ◽  
Emilie Chouzenoux

In brain MRI radiomics studies, the non-biological variations introduced by different image acquisition settings, namely scanner effects, affect the reliability and reproducibility of the radiomics results. This paper assesses how the preprocessing methods (including N4 bias field correction and image resampling) and the harmonization methods (either the six intensity normalization methods working on brain MRI images or the ComBat method working on radiomic features) help to remove the scanner effects and improve the radiomic feature reproducibility in brain MRI radiomics. The analyses were based on in vitro datasets (homogeneous and heterogeneous phantom data) and in vivo datasets (brain MRI images collected from healthy volunteers and clinical patients with brain tumors). The results show that the ComBat method is essential and vital to remove scanner effects in brain MRI radiomic studies. Moreover, the intensity normalization methods, while not able to remove scanner effects at the radiomic feature level, still yield more comparable MRI images and improve the robustness of the harmonized features to the choice among ComBat implementations.


Author(s):  
E. Völkl ◽  
L.F. Allard ◽  
B. Frost ◽  
T.A. Nolan

Off-axis electron holography has the well known ability to preserve the complex image wave within the final, recorded image. This final image described by I(x,y) = I(r) contains contributions from the image intensity of the elastically scattered electrons IeI (r) = |A(r) exp (iΦ(r)) |, the contributions from the inelastically scattered electrons IineI (r), and the complex image wave Ψ = A(r) exp(iΦ(r)) as:(1) I(r) = IeI (r) + Iinel (r) + μ A(r) cos(2π Δk r + Φ(r))where the constant μ describes the contrast of the interference fringes which are related to the spatial coherence of the electron beam, and Φk is the resulting vector of the difference of the wavefront vectors of the two overlaping beams. Using a software package like HoloWorks, the complex image wave Ψ can be extracted.


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