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Measuring torsional eye movements by tracking stable iris features.

Ong JK, Haslwanter T - J. Neurosci. Methods (2010)

Bottom Line: We propose a new method to measure torsional eye movements from videos taken of the eye.In this method, we track iris features that have been identified as Maximally Stable Volumes.These features, which are stable over time, are dark regions with bright borders that are steep in intensity.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Device Engineering, FH OO Forschungs & Entwicklungs GmbH, Upper Austria University of Applied Sciences, Garnisonstr 21, 4020 Linz, Austria. james.ong@fh-linz.at

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(a) Image derived by applying the polar transform to a raw image taken from a video of a macaque eye. (b) The features that we find are shown superimposed on the polar transformed image in black. Here, three of the features are created by eyelashes because the macaque eyelashes are similar in intensity to the iris. However, these cause no problem for our tracking algorithm since there are so many other features present.
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fig0035: (a) Image derived by applying the polar transform to a raw image taken from a video of a macaque eye. (b) The features that we find are shown superimposed on the polar transformed image in black. Here, three of the features are created by eyelashes because the macaque eyelashes are similar in intensity to the iris. However, these cause no problem for our tracking algorithm since there are so many other features present.

Mentions: The final step of our validation involved applying our torsional tracking method to a video of macaque iris, which was recorded in the infrared. Such videos are typically considered to be almost featureless, but nonetheless, our method was able to find features on the iris that are stable in time, meaning that we can track them. Fig. 7 shows the position of the features in one frame of the video. A number of the features found are caused by the eyelashes, since they appear to be a similar intensity to the iris. We could naturally remove these by explicitly finding the eyelids and excluding features near the eyelids, but in this case, they should not cause a problem, since there are so many other features present. For this video, the monkey was stationary, and since there was no torsional movement of the eyes, we have omitted the corresponding torsion plot.


Measuring torsional eye movements by tracking stable iris features.

Ong JK, Haslwanter T - J. Neurosci. Methods (2010)

(a) Image derived by applying the polar transform to a raw image taken from a video of a macaque eye. (b) The features that we find are shown superimposed on the polar transformed image in black. Here, three of the features are created by eyelashes because the macaque eyelashes are similar in intensity to the iris. However, these cause no problem for our tracking algorithm since there are so many other features present.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2958308&req=5

fig0035: (a) Image derived by applying the polar transform to a raw image taken from a video of a macaque eye. (b) The features that we find are shown superimposed on the polar transformed image in black. Here, three of the features are created by eyelashes because the macaque eyelashes are similar in intensity to the iris. However, these cause no problem for our tracking algorithm since there are so many other features present.
Mentions: The final step of our validation involved applying our torsional tracking method to a video of macaque iris, which was recorded in the infrared. Such videos are typically considered to be almost featureless, but nonetheless, our method was able to find features on the iris that are stable in time, meaning that we can track them. Fig. 7 shows the position of the features in one frame of the video. A number of the features found are caused by the eyelashes, since they appear to be a similar intensity to the iris. We could naturally remove these by explicitly finding the eyelids and excluding features near the eyelids, but in this case, they should not cause a problem, since there are so many other features present. For this video, the monkey was stationary, and since there was no torsional movement of the eyes, we have omitted the corresponding torsion plot.

Bottom Line: We propose a new method to measure torsional eye movements from videos taken of the eye.In this method, we track iris features that have been identified as Maximally Stable Volumes.These features, which are stable over time, are dark regions with bright borders that are steep in intensity.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Device Engineering, FH OO Forschungs & Entwicklungs GmbH, Upper Austria University of Applied Sciences, Garnisonstr 21, 4020 Linz, Austria. james.ong@fh-linz.at

Show MeSH
Related in: MedlinePlus