Methods and systems for imaging skin using polarized lighting
An imaging system for imaging skin includes a light source to illuminate a subject and a first polarizer to polarize light provided by the light source to illuminate the subject. The imaging system also includes a photodetector to acquire an image of the subject as illuminated by the light source and an adjustable second polarizer, coupled to the photodetector, to provide an adjustable degree of polarization of light received by the photodetector.
1. A method of generating a sub-surface skin image, comprising:
at a system having a memory and one or more processor for processing and displaying images of skin:
illuminating a subject with polarized light having a first polarization;
setting an adjustable polarizer to a first setting to admit light having the first polarization onto a photodetector and otherwise reject light;
with the adjustable polarizer in the first setting, using the photodetector to acquire a first image of the illuminated subject;
setting the adjustable polarizer to a second setting to at least partially reject light having the first polarization and to at least partially admit light having polarization distinct from the first polarization onto the photodetector;
with the adjustable polarizer in the second setting, using the photodetector to acquire a second image of the illuminated subject; and
subtracting the first image from the second image to generate a third image of the subject.
2. The method of claim 1 , further comprising:
performing computerized analysis of the third image to determine a skin color of the subject; and
using the skin color to automatically select a recommended cosmetic product.
3. The method of claim 2 , further comprising:
transmitting instructions to an automated cosmetic formulation system to produce the recommended cosmetic product.
4. The method of claim 1 , further comprising:
performing computerized analysis of the third image to identify a skin feature in the third image; and
performing an automated comparison of the identified skin feature to a corresponding skin feature in a stored historical image.
5. The method of claim 1 , further comprising:
calibrating the photodetector; and
correcting the first and second images in accordance with the calibration.
6. A computer-implemented method of processing and displaying images of skin, comprising:
at a system having a memory and one or more processor for processing and displaying images of skin:
receiving a first image of a subject, the first image having been acquired at an optical apparatus with the subject illuminated with light having a first polarization and the optical apparatus configured to receive light having the first polarization and to otherwise reject light;
receiving a second image of the subject, the second image having been acquired at the optical apparatus with the subject illuminated with light having the first polarization and the optical apparatus configured to at least partially reject light having the first polarization and to at least partially receive light having polarization distinct from the first polarization;
subtracting the first image from the second image to generate a third image of the subject; and
displaying the third image.
7. A system for processing and displaying images of skin, comprising:
memory;
a display;
one or more processors; and
one or more programs stored in the memory and configured for execution by the one or more processors, the one or more programs including:
instructions to receive a first image of a subject, the first image having been acquired at an optical apparatus with the subject illuminated with light having a first polarization and the optical apparatus configured to receive light having the first polarization and to otherwise reject light;
instructions to receive a second image of the subject, the second image having been acquired at the optical apparatus with the subject illuminated with light having the first polarization and the optical apparatus configured to at least partially reject light having the first polarization and to at least partially receive light having polarization distinct from the first polarization;
instructions to subtract the first image from the second image to generate a third image of the subject; and
instructions to display the third image.
8. A computer readable storage medium storing one or more programs configured to be executed by a computer system to process and display images of skin, the one or more programs comprising:
instructions to receive a first image of a subject, the first image having been acquired at an optical apparatus with the subject illuminated with light having a first polarization and the optical apparatus configured to receive light having the first polarization and to otherwise reject light;
instructions to receive a second image of the subject, the second image having been acquired at the optical apparatus with the subject illuminated with light having the first polarization and the optical apparatus configured to at least partially reject light having the first polarization and to at least partially receive light having polarization distinct from the first polarization;
instructions to subtract the first image from the second image to generate a third image of the subject; and
instructions to display the third image.