Wide dynamic range image sensor and method performed by the same
An image sensor is provided. The image sensor includes: a plurality of pixels provided in a pixel array; a controller configured to control a first pixel group of the plurality of pixels to have a first exposure integration time and a second pixel group of the plurality of pixels to have a second exposure integration time; and a signal processor configured to generate image data based on digital signals corresponding to pixel signals generated by the pixel array, by performing operations on a first value of the digital signals corresponding to the first pixel group and a second value of the digital signals corresponding to the second pixel group. The first exposure integration time of the first pixel group is independent of illuminance of the image data.
1. An image sensor comprising:
a pixel array comprising a plurality of pixels;
a controller configured to control a first pixel group of the plurality of pixels to have a first exposure integration time, a second pixel group of the plurality of pixels to have a second exposure integration time and a third pixel group of the plurality of pixels to have a third exposure integration time; and
a signal processor configured to generate image data based on digital signals corresponding to pixel signals generated by the pixel array, by performing operations on a first value of the digital signals corresponding to the first pixel group, a second value of the digital signals corresponding to the second pixel group and a third value of the digital signals corresponding to the third pixel group,
wherein the first pixel group has a fixed position and the first exposure integration time of the first pixel group is independent of illuminance of the image data, and
wherein the signal processor is further configured to identify the second pixel group and the third pixel group based on the illuminance.
2. The image sensor of claim 1 , wherein the signal processor is further configured to identify the illuminance based on the digital signals, identify the second exposure integration time based on the illuminance, and set the controller based on the second pixel group and the second exposure integration time.
3. The image sensor of claim 2 , wherein the first pixel group comprises a plurality of first rows of the pixel array,
wherein the second pixel group comprises at least one second row between two of the plurality of first rows, and
wherein the second pixel group comprises another second row between a different two of the plurality of first rows.
4. The image sensor of claim 2 , wherein the signal processor is further configured to normalize the first value and the second value, and reduce a weight of the second value based on a difference between the normalized first value and the normalized second value being greater than or equal to a reference value.
5. The image sensor of claim 1 , wherein each of the plurality of pixels comprises a first photoelectric element and a second photoelectric element that is larger than the first photoelectric element, and
wherein the controller is further configured to control the first photoelectric element of each pixel of the second pixel group to have the second exposure integration time and the second photoelectric element of each pixel of the second pixel group to have a fourth exposure integration time that is different from the second exposure integration time.
6. The image sensor of claim 5 , wherein the second exposure integration time is equal to or less than the first exposure integration time when the illuminance is greater than a first threshold value, and
wherein the fourth exposure integration time is equal to or greater than the second exposure integration time when the illuminance is greater than the first threshold value.
7. The image sensor of claim 5 , wherein the second exposure integration time is equal to or greater than the first exposure integration time when the illuminance is less than a second threshold value, and
wherein the fourth exposure integration time is equal to or less than the second exposure integration time when the illuminance is less than the second threshold value.
8. The image sensor of claim 5 , wherein the controller is further configured to control the first photoelectric element and the second photoelectric element of each pixel of the first pixel group to have the first exposure integration time, and
wherein the first exposure integration time is longer than the second exposure integration time and shorter than the fourth exposure integration time.
9. The image sensor of claim 1 , wherein the signal processor is further configured to control each of the plurality of pixels to have a first conversion gain or a second conversion gain based on a value of the digital signals.
10. The image sensor of claim 1 , wherein the signal processor is further configured to normalize at least one of the first value and the second value based on the first exposure integration time and the second exposure integration time, and calculate a weighted sum of the normalized first value and the normalized second value.
11. The image sensor of claim 1 , wherein the signal processor is further configured to identify the second pixel group by assigning pixels, of the plurality of pixels, to the second pixel group based on the illuminance.
12. An image sensor comprising:
a pixel array comprising a plurality of pixels;
a controller configured to control a first pixel group of the plurality of pixels to have a first exposure integration time, a second pixel group of the plurality of pixels to have a second exposure integration time and a third pixel group of the plurality of pixels to have a third exposure integration time; and
a signal processor configured to identify an illuminance based on digital signals corresponding to pixel signals generated by the pixel array, identify both the second pixel group and the second exposure integration time based on the illuminance, identify both the third pixel group and the third exposure integration time based on the illuminance, and set the controller based on the second exposure integration time and the third exposure integration time,
wherein the first pixel group has a fixed position and the first exposure integration time of the first pixel group is independent of the illuminance.
13. The image sensor of claim 12 , wherein the first pixel group comprises a plurality of first rows in the pixel array that are spaced apart from each other at equal intervals, and
wherein the second pixel group comprises at least two of a plurality of second rows between two different pairs of the plurality of first rows.
14. The image sensor of claim 12 , wherein the signal processor is further configured to normalize a first value of the digital signals corresponding to the first pixel group and a second value of the digital signals corresponding to the second pixel group, based on the first exposure integration time and the second exposure integration time.
15. The image sensor of claim 14 , wherein the signal processor is further configured to generate image data based on a weighted sum of the normalized first value and the normalized second value.
16. The image sensor of claim 14 , wherein the signal processor is further configured to reduce a weight of the second value when a difference between the normalized first value and the normalized second value is greater than or equal to a reference value.
17. The image sensor of claim 12 , wherein each of the plurality of pixels comprises a first photoelectric element and a second photoelectric element that is larger than the first photoelectric element, and
wherein the signal processor is configured to set the controller such that the first photoelectric element of each pixel of the second pixel group have the second exposure integration time and the second photoelectric element of each pixel of the second pixel group have a fourth exposure integration time different from the second exposure integration time.
18. The image sensor of claim 17 , wherein the second exposure integration time is equal to or less than the first exposure integration time when the illuminance is greater than a first threshold value, and
wherein the fourth exposure integration time is equal to or greater than the second exposure integration time when the illuminance is greater than the first threshold value.
19. The image sensor of claim 17 , wherein the second exposure integration time is equal to or greater than the first exposure integration time when the illuminance is less than a second threshold value, and
wherein the fourth exposure integration time is equal to or less than the second exposure integration time when the illuminance is less than the second threshold value.
20. A method performed by an image sensor, the method comprising:
generating digital signals based on pixel signals generated by a pixel array comprising a plurality of pixels;
identifying a second pixel group of the plurality of pixels based on illuminance;
identifying a third pixel group of the plurality of pixels based on illuminance;
driving a first pixel group of the plurality of pixels to have a first exposure integration time, the second pixel group to have a second exposure integration time and the third pixel group to have a third exposure integration time; and
generating image data based on a weighted sum of a first value of the digital signals corresponding to the first pixel group, a second value of the digital signals corresponding to the second pixel group and a third value of the digital signals corresponding to the third pixel group,
wherein the first pixel group has a fixed position and the first exposure integration time of the first pixel group is independent of the illuminance of the image data.