Imaging apparatus and method of calculating color temperature
View Patent ↗A control unit calculates the color temperature using at least a first visible light signal and a near-infrared signal when the amount of the near-infrared signal is larger than a predetermined amount. The first visible light signal is a signal generated by photoelectrically converting visible light. The near-infrared signal is a signal generated by photoelectrically converting near-infrared light.
1. An imaging apparatus comprising:
an imaging device that receives visible light and near-infrared light; and
a calculation unit configured to calculate a color temperature,
wherein the imaging device includes:
a first photoelectric converting element that photoelectrically converts visible light transmitted through a first color filter to generate a first visible light signal as a visible light signal, the first color filter transmitting at least the visible light;
a second photoelectric converting element that photoelectrically converts near-infrared light transmitted through a second color filter to generate a near-infrared signal, the second color filter transmitting at least the near-infrared light;
a third photoelectric converting element that photoelectrically converts visible light transmitted through a third color filter to generate a second visible light signal as a visible light signal, the third color filter transmitting the visible light having a wavelength different from a wavelength of the visible light transmitted by the first color filter,
the calculation unit is configured to calculate a second ratio, the second ratio being calculated by dividing the first visible light signal by the second visible light signal, when an amount of the near-infrared signal is not more than a predetermined amount, and
the calculation unit is configured to calculate the color temperature based on the second ratio.
2. The imaging apparatus according to claim 1 ,
wherein the calculation unit is configured to calculate a first ratio, the first ratio being calculated by dividing the near-infrared signal by the first visible light signal, when the amount of the near-infrared signal is larger than the predetermined amount, and
the calculation unit is configured to calculate the color temperature using the first ratio and a comparison table showing information for calculating a color temperature corresponding to the first ratio.
3. The imaging apparatus according to claim 1 ,
wherein the visible light transmitted through the first color filter is light of a red component, and
the first visible light signal is a red-light signal.
4. The imaging apparatus according to claim 1 ,
wherein
the calculation unit is configured to calculate the color temperature using the second ratio and a comparison table showing information for calculating a color temperature corresponding to the second ratio.
5. The imaging apparatus according to claim 4 ,
wherein the calculation unit is configured to calculate a first ratio as a ratio of the near-infrared signal to the first visible light signal when the amount of the near-infrared signal is larger than the predetermined amount, and
the calculation unit is configured to calculate the color temperature using the first ratio and a comparison table showing information for calculating a color temperature corresponding to the first ratio.
6. The imaging apparatus according to claim 1 ,
wherein the visible light transmitted through the first color filter is light of a red component,
the visible light transmitted through the third color filter is light of a green component,
the first visible light signal is a red-light signal, and
the second visible light signal is a green-light signal.
7. An imaging apparatus comprising:
an imaging device that receives visible light and near-infrared light; and
a calculation unit configured to calculate a color temperature,
wherein the imaging device includes:
a first photoelectric converting element that photoelectrically converts visible light transmitted through a first color filter to generate a first visible light signal as a visible light signal, the first color filter transmitting at least the visible light;
a second photoelectric converting element that photoelectrically converts near-infrared light transmitted through a second color filter to generate a near-infrared signal, the second color filter transmitting at least the near-infrared light; and
a third photoelectric converting element that photoelectrically converts visible light transmitted through a third color filter to generate a second visible light signal as a visible light signal, the third color filter transmitting the visible light having a wavelength different from a wavelength of the visible light transmitted by the first color filter,
the calculation unit is configured to calculate a second difference as a difference between the first visible light signal and the second visible light signal when an amount of the near-infrared signal is not more than a predetermined amount, and
the calculation unit is configured to calculate the color temperature based on the second difference.
8. The imaging apparatus according to claim 7 ,
wherein the calculation unit is configured to calculate a first difference as a difference between the first visible light signal and the near-infrared signal when the amount of the near-infrared signal is larger than the predetermined amount, and
the calculation unit is configured to calculate the color temperature using the first difference and a comparison table showing information for calculating a color temperature corresponding to the first difference.
9. The imaging apparatus according to claim 7 ,
wherein the calculation unit is configured to calculate the color temperature using the second difference and a comparison table showing information for calculating a color temperature corresponding to the second difference.
10. The imaging apparatus according to claim 9 ,
wherein the calculation unit is configured to calculate a first difference as a difference between the first visible light signal and the near-infrared signal when the amount of the near-infrared signal is larger than the predetermined amount, and
the calculation unit is configured to calculate the color temperature using the first difference and a comparison table showing information for calculating a color temperature corresponding to the first difference.
11. The imaging apparatus according to claim 7 ,
wherein the visible light transmitted through the first color filter is light of a red component, and
the first visible light signal is a red-light signal.
12. The imaging apparatus according to claim 7 ,
wherein the visible light transmitted through the first color filter is light of a red component,
the visible light transmitted through the third color filter is light of a green component,
the first visible light signal is a red-light signal, and
the second visible light signal is a green-light signal.