Image sensor with low noise and high resolution and operating method thereof
An image sensor includes a pixel array including a plurality of pixels, a readout circuit configured to generate a digital signal from the pixel signal received from the pixel array, and a signal processor configured to determine whether to perform a binning on a first pixel group and a second pixel group among the plurality of pixels based on at least one of a first value of the digital signal corresponding to the first pixel group and a second value corresponding to the second pixel group adjacent to the first pixel group, and generate image data based on a first operation with the first value and the second value are used as operands when the binning being determined to be performed.
1. An image sensor comprising:
a pixel array including a plurality of pixels;
a readout circuit configured to generate a digital signal based on a pixel signal received from the pixel array; and
a signal processor configured to
determine whether to perform a binning on a first pixel group and a second pixel group among the plurality of pixels based on at least one of a first value of the digital signal corresponding to the first pixel group independent of the second pixel group and a second value of the digital signal corresponding to the second pixel group adjacent to the first pixel group independent of the first pixel group, and
generate image data based on a first operation with the first value and the second value as operands when the binning is determined to be performed.
2. The image sensor of claim 1 , wherein the signal processor is further configured to generate the image data based on a second operation with the first value as an operand and independent of the second value and a third operation with the second value as an operand and independent of the first value when the binning is determined not to be performed.
3. The image sensor of claim 1 , wherein the signal processor is further configured to
identify illuminance based on at least one of the first value and the second value, and
determine to perform the binning when the illuminance is in at least one illumination range.
4. The image sensor of claim 3 , wherein the at least one illumination range comprises a range in which the illuminance is less than a first threshold value.
5. The image sensor of claim 3 , wherein
each of the first value and the second value comprises values corresponding to a plurality of modes, and
the at least one illumination range comprises a range including a boundary between two modes among the plurality of modes.
6. The image sensor of claim 5 , wherein the plurality of modes comprise a mode corresponding to a first conversion gain of each of the plurality of pixels and a mode corresponding to a second conversion gain of each of the plurality of pixels.
7. The image sensor of claim 5 , wherein
each of the plurality of pixels comprises a first photoelectric device and a second photoelectric device larger than the first photoelectric device, and
the plurality of modes comprise a mode corresponding to charges accumulated by the first photoelectric device and a mode corresponding to charges accumulated by the second photoelectric device.
8. The image sensor of claim 3 , wherein the first operation is a weighted sum of the first value and the second value.
9. The image sensor of claim 8 , wherein the signal processor is further configured to identify a first weight of the first value and a second weight of the second value, based on the at least one illumination range including the illuminance.
10. The image sensor of claim 1 , further comprising:
a driver configured to drive the pixel array; and
a controller configured to control the driver so that the first pixel group and the second pixel group have a first exposure integration time and a second exposure integration time, respectively.
11. The image sensor of claim 10 , wherein
the signal processor is further configured to
identify illuminance based on at least one of the first value and the second value,
identify the second pixel group and the second exposure integration time based on the illuminance, and
set the controller based on the identified second pixel group and the identified second exposure integration time, and
the first pixel group is independent of the illuminance.
12. The image sensor of claim 1 , wherein
each of the plurality of pixels comprises a first photoelectric device and a second photoelectric device larger than the first photoelectric device, and
further comprising:
a driver configured to drive the pixel array; and
a controller configured to control the driver such that the first pixel group has a first exposure integration time, the first photoelectric device of the second pixel group has a second exposure integration time less than or equal to the first exposure integration time, and the second photoelectric device of the second pixel group has a third exposure integration time greater than or equal to the second exposure integration time.
13. The image sensor of claim 1 , wherein the signal processor is further configured to
identify a temperature of the image sensor from a temperature signal and
determine whether to perform the binning based on the temperature and at least one of the first value and the second value.
14. An image sensor comprising:
a pixel array including a plurality of pixels including a first pixel group and a second pixel group adjacent to the first pixel group;
a readout circuit configured to generate a digital signal from a pixel signal received from the pixel array; and
a signal processor configured to
identify illuminance based on at least one of a first value of the digital signal corresponding to the first pixel group independent of the second pixel group and a second value of the digital signal corresponding to the second pixel group, and
generate image data based on a first operation with the first value and the second value as operands when the illuminance is less than or equal to a first threshold.
15. The image sensor of claim 14 , wherein the signal processor is further configured to generate the image data based on a second calculation with the first value as an operand and independent of the second value and a third calculation with the second value as an operand and independent of the first value, when the illuminance is greater than or equal to the first threshold or less than a second threshold.
16. The image sensor of claim 15 , wherein the signal processor is further configured to generate the image data when a fourth operation with the first value and the second value as operands, based on the illuminance is greater than or equal to the second threshold or less than a third threshold.
17. The image sensor of claim 16 , wherein the signal processor is further configured to generate the image data based on a fifth operation with the first value as an operand and independent of the second value and a sixth operation with the second value as an operand and independent of the first value, when the illuminance is greater than or equal to the third threshold or less than a fourth threshold.
18. An operating method of an image sensor, the operating method comprising:
generating a digital signal from a pixel signal received from a pixel array including a plurality of pixels;
determining whether to perform a binning on a first pixel group and a second pixel group among the plurality of pixels based on whether at least one of a first value of the digital signal corresponding to the first pixel group independent of the second pixel group and a second value of the digital signal corresponding to the second pixel group adjacent to the first pixel group independent of the first pixel group falls within a range defined by at least one threshold value; and
generating image data based on a first operation with the first value and the second value as operands when the binning is determined to be performed.
19. The operating method of claim 18 , further comprising generating the image data based on a second operation with the first value as an operand and independent of the second value and a third operation with the second value as an operand and independent of the first value when the binning is determined not to be performed.
20. The operating method of claim 18 , wherein the determining whether to perform the binning comprises:
identifying illuminance based on at least one of the first value and the second value; and
determining to perform the binning when the illuminance is included in at least one illumination range.