Imaging device, imaging method, recording medium, and mobile body
An imaging device includes a calculator, a white balance corrector, and a white balance corrector. The calculator calculates a white balance gain and an inverse gain on the basis of a first image. The white balance gain is used for correcting white balance. The inverse gain is a reciprocal number of the white balance gain. The white balance corrector corrects white balance of a captured image on the basis of the white balance gain. The white balance corrector generates a first image and outputs the generated first image to the calculator. The first image is generated by performing inverse gain correction in which the captured image whose white balance has been corrected is multiplied by the inverse gain.
1 . A vehicular imaging device comprising:
a calculator that calculates a white balance gain and an inverse gain on the basis of a first image, the white balance gain being used for correcting white balance, the inverse gain being a reciprocal number of the white balance gain;
a white balance corrector that corrects white balance of a captured image on the basis of the white balance gain;
an inverse gain corrector that generates the first image and outputs the generated first image to the calculator, the captured image whose white balance has been corrected is input to the inverse gain corrector at a first timing, the inverse gain is input to the inverse gain corrector at a second timing, the first image being generated by performing inverse gain correction in which the captured image whose white balance has been corrected is multiplied by the inverse gain; and
a delay processor that delays the second timing at which the inverse gain is input to the inverse gain corrector to coincide with the first timing at which the captured image whose white balance has been corrected is input to the inverse gain corrector.
2 . The vehicular imaging device according to claim 1 , wherein the calculator includes:
a detector that detects an in-frame region being a color temperature region within a white detection frame, the white detection frame representing a target region where white balance is to be corrected in a color temperature space; and
a white balance calculator that calculates the white balance gain and the inverse gain of the white balance gain on the basis of a color temperature of the in-frame region in the first image.
3 . The vehicular imaging device according to claim 2 , wherein
the detector calculates an integrated value of luminance values for each of color components of each pixel in the in-frame region of the first image, and
the white balance calculator calculates the white balance gain and the inverse gain by using the integrated value.
4 . The vehicular imaging device according to claim 1 , further comprising a compositor that performs composition of captured images whose white balance has been corrected, the captured images having different exposure levels.
5 . The vehicular imaging device according to claim 1 , wherein
the delay processor receives the inverse gain from the calculator, and outputs the inverse gain to the inverse gain corrector after holding the inverse gain for a time corresponding to at least one frame.
6 . A mobile body comprising:
a calculator that calculates a white balance gain and an inverse gain on the basis of a first image, the white balance gain being used for correcting white balance, the inverse gain being a reciprocal number of the white balance gain;
a white balance corrector that corrects white balance of a captured image on the basis of the white balance gain;
an inverse gain corrector that generates the first image and outputs the generated first image to the calculator, the captured image whose white balance has been corrected is input to the inverse gain corrector at a first timing, the inverse gain is input to the inverse gain corrector at a second timing, the first image being generated by performing inverse gain correction in which the captured image whose white balance has been corrected is multiplied by the inverse gain; and
a delay processor that delays the second timing at which the inverse gain is input to the inverse gain corrector to coincide with the first timing at which the captured image whose white balance has been corrected is input to the inverse gain corrector.
7 . The mobile body according to claim 6 , wherein
the delay processor receives the inverse gain from the calculator, and outputs the inverse gain to the inverse gain corrector after holding the inverse gain for a time corresponding to at least one frame.