Reducing sensor and readout circuitry noise in digital domain using reference pixels
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsKatherine R. Heinzen, Semion Kizhner, Maxime Pinchinat, Thomas P. Flatley, Dominic J. Benford
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Abstract
An improved method for correcting for noise in the digital domain is disclosed. Reference pixel fast-varying components are extracted using a Hilbert-Huang Transform Real-Time Data Processing System (HHT-DPS-RT). The reference pixels are non-photon-detecting pixels in a sensor array. The fast-varying components of the reference pixels are processed in addition to the average over the remaining trend, facilitating additional noise correction for active pixels.
Claims20
A computer program embodied on a non-transitory computer-readable storage medium, the computer program configured to cause a processor to:
- extract reference pixel fast-varying components (IMFs) using Hilbert-Huang Transform Real-Time Data Processing (HHT1);
- derive a noise correction array based on a boundary condition equal to a first plurality of IMFs plus an absolute value of respective minimums of the IMFs, using an embedded squares method heat propagation model;
- and
- subtract the noise correction array from an active pixels array to yield active corrected pixels.
A computer-implemented method, comprising:
- extracting reference pixel fast-varying components (IMFs) using a Hilbert-Huang Transform Real-Time Data Processing System (HHT1);
- biasing each IMF with an absolute value of the one-dimensional minimum of the IMF to make each IMF positive;
- replacing inner reference pixel square parameter amplitudes with the IMFs plus the absolute value of their respective minimums;
- propagating the replaced amplitudes into an active pixels squares noise correction array;
- deriving a noise correction array based on a boundary condition equal to the IMFs plus the absolute value of their respective minimums, using an embedded squares method heat propagation model;
- and
- subtracting the noise correction array from the active pixels squares noise correction array to yield active corrected pixels.
An apparatus, comprising:
- physical memory comprising computer program instructions;
- and
- a processor configured to execute the computer program instructions, wherein the processor is configured to:
- extract reference pixel fast-varying components (IMFs) using a Hilbert-Huang Transform Real-Time Data Processing System (HHT1);
- find a minimum for each IMF and bias each IMF with the absolute value of the one-dimensional minimum of the IMF to make each IMF positive;
- reduce a global trend by a subtrahend positive bias derived from the biased IMFs;
- average a remaining reference pixel trend for all reference pixels after the global trend reduction;
- replace inner reference pixel square parameter amplitudes with the IMFs plus the absolute value of their respective minimums;
- propagate the replaced amplitudes into an active pixels squares noise correction array;
- derive a noise correction array based on a boundary condition equal to the IMFs plus the absolute value of their respective minimums, using an embedded squares method heat propagation model;
- and
- subtract the noise correction array from the active pixels squares noise correction array to yield active corrected pixels.
Dependencies are inferred from the claim text.