Precision luxmeter methods for digital cameras to quantify colors in uncontrolled lighting environments
Inventors
Assignees
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Publication Number
US-11709096-B2
Publication Date
2023-07-25
Expiration Date
Abstract
In one embodiment, a diagnostic system for biological samples is disclosed. The diagnostic system includes a diagnostic instrument, and a portable electronic device. The diagnostic instrument has a reference color bar and a plurality of chemical test pads to receive a biological sample. The portable electronic device includes a digital camera to capture a digital image of the diagnostic instrument in uncontrolled lightning environments, a sensor to capture illuminance of a surface of the diagnostic instrument, a processor coupled to the digital camera and sensor to receive the digital image and the illuminance, and a storage device coupled to the processor. The storage device stores instructions for execution by the processor to process the digital image and the illuminance, to normalize colors of the plurality of chemical test pads and determine diagnostic test results in response to quantification of color changes in the chemical test pads.
Core Innovation
A digital photograph capturing method captures a digital photograph of a predetermined colored object that includes metadata and a reference color bar. Perceived colors are extracted from the reference color bar and from the predetermined colored object, and the perceived colors are normalized into normalized colors in response to an inverse color correction factor derived from perceived colors of the reference color bar under known illuminance and lighting conditions.
After normalization, the method determines a nearest illuminance within a set of illuminances under which the digital photograph is captured. The nearest illuminance determination is performed in response to the perceived colors of the reference color bar, the normalized colors of the reference color bar, and the metadata of the digital photograph, and in an additional version in response to perceived and normalized colors of both the reference color bar and the predetermined colored object together with the metadata.
For diagnostic use, the predetermined colored object is a diagnostic instrument including chemical test pads, and a color trajectory associated with the nearest illuminance is selected. The selected color trajectory is used to map normalized colors of the chemical test pad for quantifying a test, and the document further describes illuminance-dependent color trajectories and selection among illuminance-associated trajectories.
Claims Coverage
The document provides two independent claims (clm-00001 and clm-00007). Across these claims, the core inventive coverage includes normalization of perceived colors using a reference color bar and determination of a nearest illuminance from a set of illuminances using the perceived/normalized colors and metadata; one independent claim additionally normalizes perceived colors of the predetermined colored object into normalized colors.
Reference color bar with inverse color correction normalization and nearest illuminance determination
Capture a digital photograph including metadata of a predetermined colored object that includes a reference color bar; extract perceived colors of the reference color bar; normalize the perceived colors of the reference color bar into normalized colors using an inverse color correction factor determined from perceived colors under known illuminance and lighting conditions; and determine a nearest illuminance within a set of illuminances in response to the perceived colors of the reference color bar, the normalized colors of the reference color bar, and the metadata of the digital photograph.
Perceived and normalized colors of both reference color bar and predetermined colored object for nearest-illuminance determination
Capture a digital photograph including metadata of a predetermined colored object that includes a reference color bar; extract perceived colors of the reference color bar; normalize perceived colors of the reference color bar into normalized colors; normalize the perceived colors of the predetermined colored object into normalized colors; and determine a nearest illuminance within a set of illuminances in response to the perceived colors of the reference color bar, the normalized colors of the reference color bar, the normalized colors of the predetermined colored object, and the metadata of the digital photograph.
Both independent claims are directed to normalizing perceived colors using a reference color bar and then determining a nearest illuminance from a set of illuminances using the normalized or perceived colors together with digital-photo metadata.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
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