Optical element assembly, optical apparatus, estimation method, and non-transitory storage medium storing estimation program
According to the embodiment, an optical element assembly includes a wavelength selection portion and an imaging optical element. The wavelength selection portion includes a plurality of wavelength selection regions. The wavelength selection portion is configured to emit wavelengths different among the plurality of wavelength selection regions. The imaging optical element includes a plurality of different regions. The plurality of regions of the imaging optical element has focal lengths different from each other. Each of the regions of the imaging optical element optically faces corresponding one of the wavelength selection regions of the wavelength selection portion.
1 . An optical apparatus comprising:
an optical element assembly including:
a wavelength selection portion comprising a plurality of wavelength selection regions, the wavelength selection portion being configured to emit wavelengths in a predetermined range, the wavelengths being different among the plurality of wavelength selection regions; and
an imaging optical element comprising a plurality of different regions,
the plurality of regions of the imaging optical element having focal lengths different from each other, and
each of the regions of the imaging optical element optically faces corresponding one of the wavelength selection regions of the wavelength selection portion;
an image sensor configured to capture light emitted from the optical element assembly,
the image sensor including at least two different pixels, and
each of the pixels having at least two color channels; and
an image processor connected to the image sensor, the image processor including a processor configured to:
acquire images of the at least two color channels by the image sensor,
calculate a contrast of a common region of an object for each of the images of the at least two color channels, wherein the contrast is based on spatial gradients or the contrast is based on each of the images; and
estimate, based on the contrast of the common region for each of the at least two color channels, a farness/nearness and/or a distance of the object with respect one of the imaging optical element and the image sensor.
2 . The optical apparatus according to claim 1 , wherein
the processor is configured to estimate, based on a point spread function, distances of an object with respect to one of the imaging optical element and the image sensor independently of images corresponding to at least two different color channels.
3 . An estimation method of farness/nearness and/or a distance of an object using the optical apparatus defined in claim 1 , the method including:
acquiring images of the at least two color channels by an image sensor;
calculating a contrast of a common region of an object for each of the images of the at least two color channels, wherein the contrast is based on spatial gradients or the contrast is based on each of the images; and
estimating, based on the contrast of the common region for each of the at least two color channels, farness/nearness and/or a distance of the object with respect to one of the imaging optical element and the image sensor.
4 . A non-transitory storage medium storing an estimation program of farness/nearness and/or a distance of an object using the optical apparatus defined in claim 1 , the estimation program causing a computer to implement:
acquiring images of the at least two color channels by an image sensor;
calculating a contrast of a common region of an object for each of the images of the at least two color channels, wherein the contrast is based on spatial gradients or the contrast is based on each of the images; and
estimating, based on the contrast of the common region for each of the at least two color channels, farness/nearness and/or a distance of the object with respect to one of the imaging optical element and the image sensor.
5 . The optical apparatus according to claim 1 , wherein
when light beams from two object points on an object that pass through the imaging optical element and the wavelength selection portion and are transferred to respective image points are defined as a first light beam and a second light beam,
the first light beam is configured to pass through a first region of the imaging optical element and further passes through a first wavelength selection region of the wavelength selection portion, and
the second light beam is configured to pass through a second region of the imaging optical element and further passes through a second wavelength selection region of the wavelength selection portion.
6 . The optical apparatus according to claim 1 , wherein
the imaging optical element comprises at least one lens,
the lens includes the plurality of different regions in one surface of the lens, and
when the plurality of different regions includes a first region and a second region, a normal of a boundary between the first region and the second region discontinuously changes.
7 . The optical apparatus according to claim 1 , wherein
the imaging optical element has rotational symmetry, and
the wavelength selection portion has symmetry similar to the rotational symmetry of the imaging optical element.