Image obtaining method and apparatus
This application provides an image obtaining method and apparatus. The image obtaining method according to this application includes: obtaining first original image data, where the first original image data is captured by an image sensor based on an initial visible light exposure parameter and luminous intensity of an infrared illuminator; obtaining a luminance of a visible light image based on the first original image data; adjusting the visible light exposure parameter based on a first difference, where the first difference is a difference between the luminance of the visible light image and preset target luminance of the visible light image; obtaining a luminance of an infrared image based on the first original image data; adjusting the luminous intensity of the infrared illuminator based on a second difference, where the second difference is a difference between the luminance of the infrared image and preset target luminance of the infrared image.
1. A method for obtaining an image, comprising:
obtaining first original image data captured by an image sensor based on an initial visible light exposure parameter and a luminous intensity of an infrared lamp, wherein the first original image data comprises visible light image data and infrared image data;
obtaining a luminance of a visible light image derived from the first original image data;
adjusting the visible light exposure parameter based on a first difference between the luminance of the visible light image and a target luminance for of the visible light image;
obtaining a luminance of an infrared image derived from the first original image data;
adjusting the luminous intensity of the infrared lamp based on a second difference, between the luminance of the infrared image and a target luminance for the infrared image;
obtaining second original image data captured by the image sensor based on an adjusted visible light exposure parameter and an adjusted luminous intensity of the infrared lamp; and
fusing, based on visible light image data and infrared image data in the second original image data, to obtain the image;
wherein the visible light exposure parameter comprises one or more of an exposure time, an iris diameter, or an exposure gain; and
adjusting the visible light exposure parameter comprises:
when the luminance of the visible light image is lower than the target luminance for the visible light image, increasing one or more of the exposure time, the iris diameter, or the exposure gain; or
when the luminance of the visible light image is higher than the target luminance for the visible light image, decreasing one or more of the exposure time, the iris diameter, or the exposure gain;
wherein increasing one or more of the exposure time, the iris diameter, or the exposure gain comprises:
in a static scenario, first increasing the exposure time, then increasing the exposure gain, and finally increasing the iris diameter; and in a motion scenario, first increasing the exposure gain, then increasing the exposure time, and finally increasing the iris diameter; and
decreasing one or more of the exposure time, the iris diameter, or the exposure gain comprises:
in the static scenario, first decreasing the exposure time, then decreasing the exposure gain, and finally decreasing the iris diameter; and in the motion scenario, first decreasing the exposure gain, then decreasing the exposure time, and finally decreasing the iris diameter.
2. The method according to claim 1 , wherein adjusting the visible light exposure parameter comprises:
adjusting the visible light exposure parameter based on the first difference when an absolute value of the first difference falls outside a first range.
3. The method according to claim 1 , wherein before adjusting the visible light exposure parameter, the method further comprises:
adjusting the visible light exposure parameter based on an exposure parameter allocation policy corresponding to the first difference when an exposure parameter allocation policy set comprises the exposure parameter allocation policy corresponding to the first difference; or
adding a new exposure parameter allocation policy, and adjusting the visible light exposure parameter based on the new exposure parameter allocation policy when the exposure parameter allocation policy set does not comprise the exposure parameter allocation policy corresponding to the first difference.
4. The method according to claim 1 , wherein adjusting the luminous intensity of the infrared lamp based on the second difference comprises:
adjusting the luminous intensity of the infrared lamp based on the second difference when an absolute value of the second difference falls outside of a second range.
5. The method according to claim 1 , wherein adjusting the luminous intensity of the infrared lamp based on the second difference comprises:
when the luminance of the infrared image is lower than the target luminance for the infrared image, increasing the luminous intensity of the infrared lamp; or
when the luminance of the infrared image is higher than the target luminance for the infrared image, decreasing the luminous intensity of the infrared lamp.
6. The method according to claim 5 , wherein increasing the luminous intensity of the infrared lamp comprises:
increasing the luminous intensity of the infrared lamp by decreasing a duty cycle of pulse width modulation PWM of the infrared lamp; and
decreasing the luminous intensity of the infrared lamp comprises:
decreasing the luminous intensity of the infrared lamp by increasing the duty cycle of the PWM of the infrared lamp.
7. The method according to claim 1 , wherein adjusting the visible light exposure parameter based on the first difference comprises:
adjusting the visible light exposure parameter based on the first difference between N consecutive frames, wherein Nis a positive integer greater than one and when an absolute value of a first difference between the N consecutive frames falls outside of the first range.
8. The method according to claim 7 , wherein adjusting the visible light exposure parameter comprises:
when a luminance of the N consecutive frames of visible light images is lower than the target luminance for the visible light image, increasing one or more of the exposure time, the iris diameter, or the exposure gain; or
when the luminance of the N consecutive frames of visible light images is higher than the target luminance for the visible light image, decreasing one or more of the exposure time, the iris diameter, or the exposure gain.
9. The method according to claim 1 , wherein adjusting the luminous intensity of the infrared lamp based on the second difference comprises:
if an absolute value of the second difference between M consecutive frames of infrared images falls outside of the second range, adjusting the luminous intensity of the infrared lamp based on the second difference, wherein M is a positive integer greater than one.
10. The method according to claim 9 , wherein adjusting the luminous intensity of the infrared lamp based on the second difference comprises:
when a luminance of the M consecutive frames is lower than the target luminance for the infrared image, increasing the luminous intensity of the infrared lamp; or
when the luminance of the M consecutive frames of infrared images is higher than the target luminance for the infrared image, decreasing the luminous intensity of the infrared lamp.
11. An imaging apparatus, comprising:
a first obtaining module configured to obtain first original image data captured using an image sensor and based on an initial visible light exposure parameter and a luminous intensity of an infrared lamp, wherein the first original image data comprises visible light image data and infrared image data;
one or more processors, configured to execute the obtaining module and to obtain a luminance of a visible light image based on the first original image data, and adjust the visible light exposure parameter based on a first difference between the luminance of the visible light image and a target luminance for the visible light image;
the one or more processors being further configured to obtain a luminance of an infrared image based on the first original image data, and to adjust the luminous intensity of an infrared lamp based on a second difference between the luminance of the infrared image and a target luminance for the infrared image;
the one or more processors being further configured to execute a second obtaining module configured to obtain second original image data captured by the image sensor based on an adjusted visible light exposure parameter and an adjusted luminous intensity of the infrared lamp; and
wherein the one or more processors are further configured to execute a fusion module configured to fuse, based on the visible light image data and the infrared image data in the second original image data, to obtain a target image;
wherein the visible light exposure parameter comprises one or more of an exposure time, an iris diameter, or an exposure gain; and
adjusting the visible light exposure parameter comprises:
when the luminance of the visible light image is lower than the target luminance for the visible light image, increasing one or more of the exposure time, the iris diameter, or the exposure gain; or
when the luminance of the visible light image is higher than the target luminance for the visible light image, decreasing one or more of the exposure time, the iris diameter, or the exposure gain;
wherein increasing one or more of the exposure time, the iris diameter, or the exposure gain comprises:
in a static scenario, first increasing the exposure time, then increasing the exposure gain, and finally increasing the iris diameter; and in a motion scenario, first increasing the exposure gain, then increasing the exposure time, and finally increasing the iris diameter; and
decreasing one or more of the exposure time, the iris diameter, or the exposure gain comprises:
in the static scenario, first decreasing the exposure time, then decreasing the exposure gain, and finally decreasing the iris diameter; and in the motion scenario, first decreasing the exposure gain, then decreasing the exposure time, and finally decreasing the iris diameter.
12. The apparatus according to claim 11 , wherein the first processor is further configured to:
adjust the visible light exposure parameter based on the first difference when an absolute value of the first difference falls outside a first range.
13. The apparatus according to claim 11 , wherein the first processor is further configured to:
adjust the visible light exposure parameter based on an exposure parameter allocation policy corresponding to the first difference when an exposure parameter allocation policy set comprises the exposure parameter allocation policy corresponding to the first difference; or
add a new exposure parameter allocation policy, and adjust the visible light exposure parameter based on the new exposure parameter allocation policy when the exposure parameter allocation policy set does not comprise the exposure parameter allocation policy corresponding to the first difference.
14. The apparatus according to claim 11 , wherein the visible light exposure parameter comprises one or more of an exposure time, an iris diameter, or an exposure gain; and
The one or more processors are further configured to adjust the visible light exposure parameter by:
when the luminance of the visible light image is lower than the target luminance for the visible light image, increasing one or more of the exposure time, the iris diameter, or the exposure gain; or
when the luminance of the visible light image is higher than the target luminance for the visible light image, decreasing one or more of the exposure time, the iris diameter, or the exposure gain.
15. The apparatus according to claim 11 , wherein the one or more processors are further configured to adjust the luminous intensity of the infrared lamp based on the second difference by:
adjusting the luminous intensity of the infrared lamp based on the second difference when an absolute value of the second difference falls outside of a second range.
16. The apparatus according to claim 11 , wherein the one or more processors are further configured to adjust the luminous intensity of the infrared lamp based on the second difference by:
when the luminance of the infrared image is lower than the target luminance for the infrared image, increasing the luminous intensity of the infrared lamp; or
when the luminance of the infrared image is higher than the target luminance for the infrared image, decreasing the luminous intensity of the infrared lamp.
17. The apparatus according to claim 16 , wherein the one or more processors are further configured to increase the luminous intensity of the infrared lamp by:
increasing the luminous intensity of the infrared lamp by decreasing a duty cycle of pulse width modulation PWM of the infrared lamp; and
wherein the one or more processors are further configured to decrease the luminous intensity of the infrared lamp by:
decreasing the luminous intensity of the infrared lamp by increasing the duty cycle of the PWM of the infrared lamp.
18. The apparatus according to claim 11 , wherein the one or more processors are further configured to adjust the visible light exposure parameter by:
if an absolute value of a difference between N consecutive frames of visible light images falls outside of the first range, adjusting the visible light exposure parameter based on the difference between the N consecutive frames, wherein N is a positive integer greater than one.