Imaging apparatus, imaging method, and program
The present disclosure relates to an imaging apparatus, an imaging method, and a program that enable exposure control on a captured image in a non-Bayer pattern by an exposure control method designed for captured images in Bayer patterns. When a Bayering process is performed on a captured image in an RGBW pixel array, a level correction unit corrects the signal level of the captured image so that an earlier level that is the signal level of each white pixel with the highest sensitivity in the captured image prior to the Bayering process becomes equal to a later level that is the signal level of each green pixel to be used in exposure control on an image in a Bayer pattern that is the RGB image after the Bayering process. The present disclosure can be applied to imaging apparatuses, for example.
1. An imaging apparatus comprising
a level correction unit configured to correct a signal level of a captured image in a non-Bayer pattern when a Bayering process is performed on the captured image, to make an earlier level equal to a later level, the earlier level being a signal level of a pixel with the highest sensitivity in the captured image prior to the Bayering process, the later level being a signal level of a pixel to be used in exposure control on an image in a Bayer pattern, the image in the Bayer pattern being the captured image after the Bayering process.
2. The imaging apparatus according to claim 1 , further comprising
a correction gain calculation unit configured to calculate, in accordance with the earlier level and the later level, a correction gain by which the signal level of the captured image is to be multiplied to make the earlier level equal to the later level,
wherein the level correction unit multiplies the signal level of the captured image by the correction gain calculated by the correction gain calculation unit.
3. The imaging apparatus according to claim 1 , further comprising
a white balance control unit configured to control white balance of the captured image when the Bayering process is performed on the captured image in the non-Bayer pattern, to make a ratio among signal levels of RGB in the captured image prior to the Bayering process becomes equal to a ratio among signal levels of RGB in the captured image after the Bayering process.
4. The imaging apparatus according to claim 3 , further comprising
a white balance unit configured to multiply the captured image in the non-Bayer pattern by white balance gain when the Bayering process is performed on the captured image,
wherein the white balance control unit controls the white balance of the captured image by multiplying the captured image multiplied by the white balance gain, by a reciprocal of the white balance gain.
5. The imaging apparatus according to claim 4 , further comprising
a white balance gain calculation unit configured to calculate the white balance gain in accordance with the captured image when the Bayering process is performed on the captured image in the non-Bayer pattern.
6. The imaging apparatus according to claim 4 , wherein the white balance gain is calculated when predetermined signal processing is performed with the captured image after the Bayering process.
7. The imaging apparatus according to claim 1 , wherein a signal of each pixel in the captured image in the non-Bayer pattern contains an invisible light component and a visible light component.
8. The imaging apparatus according to claim 7 , further comprising
a separation unit configured to separate the invisible light component and the visible light component contained in the signal,
wherein the level correction unit corrects a signal level of the visible light component separated by the separation unit.
9. An imaging method comprising
a step of correcting a signal level of a captured image in a non-Bayer pattern when an imaging apparatus performs a Bayering process on the captured image, to make an earlier level equal to a later level, the earlier level being a signal level of a pixel with the highest sensitivity in the captured image prior to the Bayering process, the later level being a signal level of a pixel to be used in exposure control on an image in a Bayer pattern, the image in the Bayer pattern being the captured image after the Bayering process.
10. A non-transitory computer-readable storage medium storing a program for causing a computer to function as a level correction unit configured to correct a signal level of a captured image in a non-Bayer pattern when a Bayering process is performed on the captured image, to make an earlier level equal to a later level, the earlier level being a signal level of a pixel with the highest sensitivity in the captured image prior to the Bayering process, the later level being a signal level of a pixel to be used in exposure control on an image in a Bayer pattern, the image in the Bayer pattern being the captured image after the Bayering process.