Media 1: Resolution limits to object tracking with subpixel accuracy

Originally published in Optics Letters on 01 December 2012 (ol-37-23-4877

Media 1: Open-access operating algorithms for commercial videokeratographer and improvement of corneal sampling

Originally published in Applied Optics on 01 March 2013 (ao-52-7-C24

Normalized velocity and acceleration computed for the example blink.

<p>Velocity and acceleration are plotted in green and red lines, respectively. Local maxima and minima of the acceleration are used to define three new features (<i>t</i>_1<i>a</i>, <i>t</i>_2<i>a</i> and <i>t</i>_3<i>a</i>).</p

Eyelid displacement (black), normalized velocity (green) and acceleration (red) for the example blink.

<p>Eyelid displacement (black), normalized velocity (green) and acceleration (red) for the example blink.</p

Coefficient of variation and boxplots of all the features.

<p>a) Coefficient of variation of all features for the blinks of each subject (color bars) and all the blinks (black bars). b) Boxplots of the features computed following Eq (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196125#pone.0196125.e025" target="_blank">9</a>).</p

Normalized data of intensity, smoothing spline, velocity and acceleration for a blink.

<p>Data correspond to the first blink of the sequence of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196125#pone.0196125.g001" target="_blank">Fig 1</a>. The data of intensity are the black crosses, the black line represents the smoothing spline, the data of velocity and acceleration are plotted in green and red lines, respectively.</p

Displacement of the eyelid.

<p>θ₁ and θ₂ describe the mean velocities in the downward and upward phases, and w stands for the fwhm of the displacement.</p

Rate of selection obtained for each feature.

<p>Percentage of selection of each blink feature obtained after recursively computing 60 times the feature subset that minimized the number of misclassified observations.</p

Features computed for the set of 1924 blinks.

<p>Features computed for the set of 1924 blinks.</p

Reflected intensity vs. time.

<p>Variation in time of the sum of the intensity of the pixels computed for an example sequence. The intensity remains almost constant in time. Peaks correspond to the eyelid closed.</p