System and method for multispectral extraction from crosstalk profile
An electronic device includes: memory; a color filter array (CFA); an image sensor operatively connected to the CFA, the image sensor being configured to capture a plurality of images respectively having a plurality of measured spectral densities in a plurality of spectral bands; and a processor operatively connected to the at least one memory and the image sensor, wherein the at least one processor is configured to: measure a plurality of crosstalk values in a plurality of pixels and in a plurality of K channels of the plurality of images (the K represents a number of pixels per a color of the CFA), estimate a plurality of spectral-crosstalk values by applying an estimation function to the plurality of crosstalk values, and control to store, in at least one of the memory, the image sensor, or the processor, the estimated plurality of spectral-crosstalk values.
1 . An electronic device comprising:
at least one memory;
a color filter array (CFA);
an image sensor operatively connected to the CFA, the image sensor being configured to capture a plurality of M images respectively having a plurality of measured spectral densities in a plurality of D spectral bands; and
at least one processor operatively connected to the at least one memory and the image sensor,
wherein the at least one processor is configured to:
measure a plurality of crosstalk values in a plurality of L pixels and in a plurality of K channels of the plurality of M images, wherein the K represents a number of pixels per a color of the CFA,
estimate a plurality of spectral-crosstalk values by applying an estimation function to the plurality of crosstalk values, and
control to store, in at least one of the at least one memory, the image sensor, or the at least one processor, the estimated plurality of spectral-crosstalk values.
2 . The electronic device of claim 1 , wherein the CFA is an up-sampled Bayer CFA.
3 . The electronic device of claim 1 , wherein the CFA is Quad Bayer, Nona pixel, or Tetra pixel.
4 . The electronic device of claim 1 , wherein the estimation function corresponds to a pseudoinverse of a spectral matrix or a neural network model.
5 . The electronic device of claim 4 , wherein the plurality of measured spectral densities are arranged in the spectral matrix.
6 . The electronic device of claim 1 , wherein the at least one processor is further configured to measure the plurality of crosstalk values in the plurality of L pixels and in the plurality of K channels of the plurality of M images, based on a plurality of deviations between pixel levels of the plurality of L pixels and average color values of the plurality of K channels.
7 . The electronic device of claim 1 , wherein the at least one processor is further configured to capture the plurality of M images using an integrating light sphere configured to measure ground-truth spectral densities of the plurality of M images.
8 . An electronic device comprising:
at least one memory;
a color filter array (CFA);
an image sensor operatively connected to the CFA, the image sensor being configured to capture a plurality of M images respectively having a plurality of measured spectral densities in a plurality of D spectral bands; and
at least one processor operatively connected to the at least one memory and the image sensor,
wherein the at least one processor is configured to:
measure a plurality of crosstalk values in a plurality of L pixels and in a plurality of K channels of the plurality of M images, wherein the K represents a number of pixels per a color of the CFA,
estimate a plurality of spectral-crosstalk values by applying an estimation function to the plurality of crosstalk values, and
control to store, in at least one of the at least one memory, the image sensor, or the at least one processor, the estimated plurality of spectral-crosstalk values,
wherein the electronic device further comprises a flat detector operatively connected to the image sensor,
wherein the at least one processor is further configured to:
receive an input image having a pattern of the CFA,
receive, from the flat detector, info on a first area of the input image, wherein the first area has a first crosstalk value,
calculate the first crosstalk value in the first area of the input image,
estimate a first spectral density of the first area by applying the pseudoinverse of the plurality of estimated spectral-crosstalk values to the calculated first crosstalk value, and
control to store, in at least one of the at least one memory, the image sensor, or the at least one processor, the estimated first spectral density of the first area, and
wherein the CFA is an up-sampled Bayer CFA.
9 . The electronic device of claim 8 , wherein the at least one processor is further configured to:
receive, from the flat detector, info on a second area of the input image, wherein the second area has a second crosstalk value,
calculate the second crosstalk value in the second area of the input image,
estimate a second spectral density of the second area by applying a pseudoinverse of the plurality of estimated spectral-crosstalk values to the calculated first crosstalk value,
control to store, in at least one of the at least one memory, the image sensor, or the at least one processor, the estimated second spectral density of the second area, and
generate a global spectral density estimate of the input image by aggregating the estimated first spectral density of the first area and the estimated second spectral density of the second area.
10 . The electronic device of claim 8 , wherein the CFA is Quad Bayer, Nona pixel, or Tetra pixel.
11 . The electronic device of claim 8 , wherein the at least one processor is further configured to measure the plurality of crosstalk values in the plurality of L pixels and in the plurality of K channels of the plurality of M images, based on a plurality of deviations between pixel levels of the plurality of L pixels and average color values of the plurality of K channels.
12 . The electronic device of claim 8 , wherein the at least one processor is further configured to capture the plurality of M images using an integrating light sphere configured to measure ground-truth spectral densities of the plurality of M images.