Imaging device and method of operating imaging device
There is provided an imaging device capable of improving image quality of a reconstructed image in lensless imaging, and a method of operating the imaging device. A mask that is provided at a preceding stage of an imaging element and modulates incident light is a mask including a pattern defined by a non-binary URA. The present disclosure can be applied to a lensless camera.
1 . An imaging device comprising:
a mask that includes a plurality of optical elements having different transmittances, the plurality of optical elements being arranged in a pattern defined by non-binary uniformly redundant arrays (URA), wherein the mask is configured to modulate incident light into modulated light by transmitting the incident light through the plurality of optical elements;
an imaging element configured to capture a modulated image including the modulated light transmitted through the mask; and
circuitry configured to reconstruct an image corresponding to the incident light based on the modulated image,
wherein a one-dimensional array of a predetermined length constituting the pattern defined by the non-binary URA is generated based on a multiplication result of one-dimensional arrays defined by non-binary URA of different lengths that are mutually prime.
2 . The imaging device according to claim 1 ,
wherein the plurality of optical elements is a plurality of filters having different transmittances and being arranged in a matrix in the pattern defined by the non-binary URA.
3 . The imaging device according to claim 2 ,
wherein the plurality of filters is ND filters.
4 . The imaging device according to claim 1 ,
wherein the plurality of optical elements includes a free-form lens having a plurality of focal lengths corresponding to the pattern defined by the non-binary URA.
5 . The imaging device according to claim 1 ,
wherein the plurality of optical elements includes a diffractive optical element having a plurality of focal lengths corresponding to the pattern defined by the non-binary URA.
6 . The imaging device according to claim 1 ,
wherein the plurality of optical elements includes a Fresnel zone plate (FZP) having a plurality of focal lengths corresponding to the pattern defined by the non-binary URA.
7 . The imaging device according to claim 1 ,
wherein each element of a one-dimensional array constituting the pattern defined by the non-binary URA is non-negative.
8 . The imaging device according to claim 1 ,
wherein the one-dimensional array having the predetermined length and constituting the pattern defined by the non-binary URA is generated by shifting and multiplying the one-dimensional arrays defined by the non-binary URA of the different lengths that are mutually prime such that periodic side lobes become zero, and further subtracting a value of a smallest element among elements constituting the array obtained as the multiplication result from each element.
9 . A method of operating an imaging device,
the imaging device including
a mask that includes a plurality of optical elements having different transmittances, the plurality of optical elements being arranged in a pattern defined by non-binary uniformly redundant arrays (URA), wherein the mask is configured to modulate incident light into modulated light by transmitting the incident light through the plurality of optical elements,
an imaging element configured to capture a modulated image including the modulated light transmitted through the mask, and
circuitry configured to reconstruct an image corresponding to the incident light based on the modulated image, and
the method comprising:
modulating the incident light into modulated light by the mask transmitting the incident light through a plurality of optical elements having different transmittances and being arranged in the pattern defined by the non-binary URA;
capturing by the imaging element a modulated image including the modulated light transmitted through the mask; and
reconstructing an image corresponding to the incident light based on the modulated image,
wherein a one-dimensional array of a predetermined length constituting the pattern defined by the non-binary URA is generated based on a multiplication result of one-dimensional arrays defined by non-binary URA of different lengths that are mutually prime.