SENSOR-SYNCHRONIZED SPECTRALLY-STRUCTURED-LIGHT IMAGING

• US 20130308045A1
• Filed: 03/15/2013
• Published: 11/21/2013
• Est. Priority Date: 05/21/2012
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B., Rodriguez, Tony F.
• Granted Patent: US 9,060,113 B2
• Time in Patent Office: Days
• US Class Current: 348/371
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/6898 Portable consumer electronic devices, e.g. music players, telephones, tablet computers
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

A smartphone is adapted for use as an imaging spectrometer, by synchronized pulsing of different LED light sources as different image frames are captured by the phone'"'"'s CMOS image sensor. A particular implementation employs the CIE color matching functions, and/or their orthogonally transformed functions, to enable direct chromaticity capture. A great variety of other features and arrangements are also detailed.

Claims

1. A flash accessory for use with a smartphone, the smartphone being equipped with a camera for capture of a multi-frame video sequence, the accessory comprising:

a housing including a portion adapted to engage a portion of the smartphone, thereby enabling the accessory to be removably attached to the smartphone, the housing containing;

plural light emitting diodes having different spectral characteristics;

an interface adapted to receive a frame timing control signal from the smartphone; and

drive circuitry coupled to said interface, and configured to independently control said plural light emitting diodes;

wherein the drive circuitry is adapted to respond to the frame timing control signal to controllably illuminate different ones of said light emitting diodes in a programmed sequence, at times corresponding to captures of different frames of a video sequence by the smartphone camera.

2. The accessory of claim 1 in which the interface is adapted to receive an audio frame timing control signal from the smartphone.

3. The accessory of claim 1 in which the interface is adapted to receive a wireless frame timing control signal from the smartphone.

4. The accessory of claim 1 in which the interface is adapted to receive a wireless frame timing control signal from the smartphone through a wire connection.

5. A smartphone comprising:

a body;

a camera portion, for capture of a multi-frame video sequence;

a flash portion, including plural light emitting diodes having different spectral characteristics; and

drive circuitry configured to independently control said plural light emitting diodes of the flash portion;

wherein the drive circuitry is adapted to controllably illuminate different ones of said light emitting diodes in a programmed sequence, at times corresponding to captures of different frames of a video sequence by the camera portion.