Figure & Image Gallery

This figure shows the variation in human skin tone values gathered using a calibrated colormeter device.  Some biometric systems have greater error rates for people with darker skin.  I am working on understanding how better imaging across the full gamut of human skin tone can improve biometric performance for people belonging to different demographic groups.

A figure I made for a recent paper quantifying the influence of face recognition algorithm outcomes on human face matching.  The colors show different levels of human face match confidence.  The overlap between two bands in the middle shows that people can arrive at different match decisions given the same face pair based on the prior algorithm outcome.

This figure shows average faces of men and women belonging to different demographic groups.  On the left is a plot showing these faces plotted as a function of the first two principal components of measured color values.  What I find striking is the spectrum of color across different people.

This is a figure from one of my papers measuring changes in neural activity correlated with perceptual adaptation to odors.  The trick was to visualize a complicated analysis showing how the form of the neural response changes over time.

This figure shows sniffing and ultrasonic squeaks of socializing rats.  When rats are paired, it is hard to know which one is talking.  By recording sniffing, we were able to tell which rat was the speaker.  Note the areas marked in red on the top trace (squeaking) correspond to the sniffing of one of the rats (middle trace), but not the other (bottom trace).

This is one of the first images I measured from the primary visual cortex.  It shows an increase in blood volume (dark spot in the middle) in response to a visual stimulus.  The white lightning bolts are actually constricting arteries and arterioles bringing fresh blood to the brain in rhythm with the task.

This image shows the columnar structure of the visual cortex.  Each color corresponds to a visual orientation in a particular point in space, like a Gabor filter.  This beautiful image shows the tiling of orientation selective cells across cortex and was actually computed from four images taken in response to full-field gratings of different orientations.

This image shows the premise of multi-spectral imaging of cerebral hemodynamics.  At the top is the absorption spectrum of hemoglobin with the emission spectra of LEDs used for illuminating the brain.  Below are the images of the brain's response to a small visual stimulus imaged at different wavelengths and different times.