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An image registration method for colposcopic images.

Mezura-Montes E, Acosta-Mesa HG, Ramírez-Garcés DD, Cruz-Ramírez N, Hernández-Jiménez R - Comput Math Methods Med (2013)

Bottom Line: The affinity value is based on polynomial approximation of the time series computed and the search is bounded by a search radius which defines the neighborhood of each window.The proposed approach is tested in ten 310-frame real cases in two experiments: the first one to determine the best values for the window size and the search radius and the second one to compare the best obtained results with respect to four registration methods found in the specialized literature.The obtained results show a robust and competitive performance of the proposed approach with a significant lower time with respect to the compared methods.

View Article: PubMed Central - PubMed

Affiliation: Department of Artificial Intelligence, University of Veracruz, Sebastián Camacho 5, 91000 Centro Xalapa, VER, Mexico.

ABSTRACT
A nonrigid body image registration method for spatiotemporal alignment of image sequences obtained from colposcopy examinations to detect precancerous lesions of the cervix is proposed in this paper. The approach is based on time series calculation for those pixels in the first image of the sequence and a division of such image into small windows. A search process is then carried out to find the window with the highest affinity in each image of the sequence and replace it with the window in the reference image. The affinity value is based on polynomial approximation of the time series computed and the search is bounded by a search radius which defines the neighborhood of each window. The proposed approach is tested in ten 310-frame real cases in two experiments: the first one to determine the best values for the window size and the search radius and the second one to compare the best obtained results with respect to four registration methods found in the specialized literature. The obtained results show a robust and competitive performance of the proposed approach with a significant lower time with respect to the compared methods.

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Related in: MedlinePlus

Four principal components and the corresponding eigenvalues.
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fig5: Four principal components and the corresponding eigenvalues.

Mentions: The definition of the polynomial approximation used in the second step of the quality calculation for the neighbor-windows is as follows: each time series (acetowhite response function, AwRF) can be represented as a discrete-time multivariable stochastic system (see (2))(2)AwRF=θ1G1+θ2G2+⋯+θnGn+e.In order to make a model to represent the general behaviour of the AwRF, a PCA analysis was developed over a set of representative AwRF. The objective of the analysis was to find the matrix G which explains the dynamics of every AwRF so as to filter high frequencies. The four principal components were selected to explain the 98.21% of the variance (see Figure 5).


An image registration method for colposcopic images.

Mezura-Montes E, Acosta-Mesa HG, Ramírez-Garcés DD, Cruz-Ramírez N, Hernández-Jiménez R - Comput Math Methods Med (2013)

Four principal components and the corresponding eigenvalues.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3794537&req=5

fig5: Four principal components and the corresponding eigenvalues.
Mentions: The definition of the polynomial approximation used in the second step of the quality calculation for the neighbor-windows is as follows: each time series (acetowhite response function, AwRF) can be represented as a discrete-time multivariable stochastic system (see (2))(2)AwRF=θ1G1+θ2G2+⋯+θnGn+e.In order to make a model to represent the general behaviour of the AwRF, a PCA analysis was developed over a set of representative AwRF. The objective of the analysis was to find the matrix G which explains the dynamics of every AwRF so as to filter high frequencies. The four principal components were selected to explain the 98.21% of the variance (see Figure 5).

Bottom Line: The affinity value is based on polynomial approximation of the time series computed and the search is bounded by a search radius which defines the neighborhood of each window.The proposed approach is tested in ten 310-frame real cases in two experiments: the first one to determine the best values for the window size and the search radius and the second one to compare the best obtained results with respect to four registration methods found in the specialized literature.The obtained results show a robust and competitive performance of the proposed approach with a significant lower time with respect to the compared methods.

View Article: PubMed Central - PubMed

Affiliation: Department of Artificial Intelligence, University of Veracruz, Sebastián Camacho 5, 91000 Centro Xalapa, VER, Mexico.

ABSTRACT
A nonrigid body image registration method for spatiotemporal alignment of image sequences obtained from colposcopy examinations to detect precancerous lesions of the cervix is proposed in this paper. The approach is based on time series calculation for those pixels in the first image of the sequence and a division of such image into small windows. A search process is then carried out to find the window with the highest affinity in each image of the sequence and replace it with the window in the reference image. The affinity value is based on polynomial approximation of the time series computed and the search is bounded by a search radius which defines the neighborhood of each window. The proposed approach is tested in ten 310-frame real cases in two experiments: the first one to determine the best values for the window size and the search radius and the second one to compare the best obtained results with respect to four registration methods found in the specialized literature. The obtained results show a robust and competitive performance of the proposed approach with a significant lower time with respect to the compared methods.

Show MeSH
Related in: MedlinePlus