Image acquisition apparatus and method of operating the same
An image acquisition apparatus includes: a sensor unit including a plurality of first image sensors that are based on a wavelength band of 380 nm to 780 nm; and at least one processor. The at least one processor is configured to: acquire common illumination information from an image output from at least one of the plurality of first image sensors, and color-convert an image output from each of the plurality of first image sensors based on the common illumination information.
1 . An image acquisition apparatus comprising:
a sensor unit comprising a plurality of first image sensors that are based on a wavelength band of 380 nm to 780 nm; and
at least one processor configured to:
acquire common illumination information from an image output from at least one of the plurality of first image sensors, and
color-convert an image output from each of the plurality of first image sensors based on the common illumination information,
wherein the at least one processor, when acquiring the common illumination information, is configured to:
acquire individual illumination information with respect to each image output from the plurality of first image sensors;
overlay the individual illumination information based on a positional relationship between pixels in the individual illumination information; and
acquire the common illumination information from the overlaid individual illumination information.
2 . The image acquisition apparatus of claim 1 , wherein in the plurality of first image sensors, at least one of focal length or field of view (FOV) are different from each other.
3 . The image acquisition apparatus of claim 2 , wherein the at least one processor being configured to overlay the individual illumination information includes being configured to over lay the individual illumination information in an order in which the focal length of the plurality of first image sensors increase or in an order in which the FOV of the plurality of first image sensors decrease.
4 . The image acquisition apparatus of claim 1 , wherein the at least one processor being configured to acquire the common illumination information includes being configure to input the image output from each of the plurality of first image sensors into a deep-learning network that is trained in advance.
5 . The image acquisition apparatus of claim 1 , wherein the at least one processor being configured to acquire the common illumination information includes being configured to acquire the common illumination information from one of the images output from the plurality of first image sensors, the plurality of first image sensors having different focal lengths and fields of view (FOVs) from each other.
6 . The image acquisition apparatus of claim 5 , wherein the sensor unit is configured to, when a focal length of a reference image sensor from which the common illumination information is acquired is greater than a focal length of a target image sensor in which color conversion is to be performed, estimate the common illumination information with respect to the target image sensor through an extrapolation.
7 . The image acquisition apparatus of claim 5 , wherein the sensor unit is configured to, when an FOV of a reference image sensor from which the common illumination information is acquired is less than an FOV of a target image sensor in which color conversion is to be performed, estimate the common illumination information with respect to the target image sensor through an extrapolation.
8 . The image acquisition apparatus of claim 1 ,
wherein the sensor unit further comprises a second image sensor configured to divide a light spectrum into more wavelength bands than the plurality of first image sensors, and
wherein the at least one processor is further configured to acquire the common illumination information from an image output from the second image sensor.
9 . The image acquisition apparatus of claim 8 , wherein the second image sensor comprises a multispectral image sensor configured to acquire images of at least four channels based on a wavelength band of 10 nm to 1000 nm.
10 . The image acquisition apparatus of claim 9 , wherein the at least one processor is further configured to acquire the common illumination information based on at least one of the at least four channels acquired from the multispectral image sensor.
11 . The image acquisition apparatus of claim 1 , wherein the common illumination information includes at least one of a color temperature of an illumination, an illumination vector corresponding to an intensity of an illumination spectrum, an XYZ vector indicating a color of illumination, an RGB vector indicating a color of illumination, or an index value indicating illumination information stored in advance, with respect to an image on which color conversion is to be performed.
12 . The image acquisition apparatus of claim 1 , wherein the at least one processor is further configured to:
divide a reference image from which the common illumination information is acquired into a plurality of regions, and
acquire illumination information for each of the plurality of regions from at least one of the plurality of regions.
13 . The image acquisition apparatus of claim 12 , wherein the at least one processor being configured to acquire the common illumination information includes being configured to acquire the common illumination information by interpolating the illumination information for each of the plurality of regions obtained from the divided reference image.
14 . The image acquisition apparatus of claim 1 , wherein the at least one processor being configured to acquire the common illumination information includes being configured to acquire the common illumination information based on a basis vector, a spatial position, and a channel index of a reference image from which the common illumination information is acquired.
15 . The image acquisition apparatus of claim 1 , wherein the at least one processor is further configured to register a first image output from a reference image sensor and a second image output from a target image sensor, based on at least one of positional information, a resolution, an optical axis, an FOV, or a focal length of each of the reference image sensor from which the common illumination information is acquired and the target image sensor on which color conversion is to be performed.
16 . The image acquisition apparatus of claim 15 , wherein the at least one processor being configured to register the first image and the second image includes being configured to register the first image and the second image based on edges and features of the first image and the second image.
17 . The image acquisition apparatus of claim 16 , wherein the at least one processor is further configured to perform a white balance on the second image based on the common illumination information of the first image.
18 . The image acquisition apparatus of claim 1 , wherein the at least one processor is further configured to perform a gamma correction or a color correction on the color-converted image.
19 . An image acquisition method comprising:
acquiring images from a plurality of first image sensors that are based on a wavelength band of 380 nm to 780 nm;
acquiring common illumination information from an image output from at least one of the plurality of first image sensors; and
color-converting the image output from each of the plurality of first image sensors based on the common illumination information,
wherein the acquiring common illumination information comprises:
acquiring individual illumination information with respect to each image output from the plurality of first image sensors;
overlaying the individual illumination information based on a positional relationship between pixels in the individual illumination information; and
acquiring the common illumination information from the overlaid individual illumination information.