Method of operating image sensor and image device performing the same
An operating method of an image sensor may include generating first result image data based on performing first image capturing. The first result image data may include a plurality of first standard dynamic range (SDR) image data and first high dynamic range (HDR) image data. The operating method may include generating first parameters based on the first result image data. The first parameters may be associated with the first image capturing and may include a plurality of first exposure times and a plurality of first sensor gains. The operating method may include generating an adjustment factor based on the first parameters and generating second parameters based on adjusting the first parameters based on the adjustment factor. The second parameters may include a plurality of second exposure times and a plurality of second sensor gains. The operating method may include generating performing second image capturing based on the second parameters.
1. An operating method of an image sensor, the operating method comprising:
generating first result image data including a plurality of first standard dynamic range (SDR) image data and first high dynamic range (HDR) image data based on performing first image capturing;
generating first parameters, which are associated with the first image capturing and include a plurality of first exposure times and a plurality of first sensor gains, based on the first result image data;
generating an adjustment factor based on the first parameters;
generating second parameters including a plurality of second exposure times and a plurality of second sensor gains based on adjusting the first parameters based on the adjustment factor; and
performing second image capturing based on the second parameters.
2. The operating method of claim 1 , wherein the generating of the second parameters includes:
generating the plurality of second exposure times and the plurality of second sensor gains based on adjusting the plurality of first exposure times and the plurality of first sensor gains to be inversely proportional to the adjustment factor.
3. The operating method of claim 1 , wherein the generating of the adjustment factor includes:
calculating a first dynamic range compression ratio based on
a first setting time and a second setting time among the plurality of first exposure times, and
a first setting gain and a second setting gain among the plurality of first sensor gains;
calculating a first illuminance level based on the first setting time and the first setting gain; and
calculating the adjustment factor based on the first dynamic range compression ratio, the first illuminance level, and a first adjustment factor relation.
4. The operating method of claim 3 , wherein
the first setting time corresponds to an exposure time that is a longest exposure time among the plurality of first exposure times,
the second setting time corresponds to another exposure time that is a shortest exposure time among the plurality of first exposure times,
the first setting gain corresponds to the first setting time, and
the second setting gain corresponds to the second setting time.
5. The operating method of claim 4 , wherein the first dynamic range compression ratio is a value obtained based on dividing a first value by a second value, the first value obtained based on multiplying the first setting time and the first setting gain together, the second value obtained based on multiplying the second setting time and the second setting gain together.
6. The operating method of claim 5 , wherein a magnitude of the adjustment factor increases as the first dynamic range compression ratio increases.
7. The operating method of claim 3 , wherein the calculating of the adjustment factor includes:
calling the first adjustment factor relation corresponding to the first illuminance level, based on an illuminance level-adjustment factor table; and
calculating the adjustment factor based on applying the first adjustment factor relation to the first dynamic range compression ratio.
8. The operating method of claim 7 , wherein the illuminance level-adjustment factor table includes:
a plurality of illuminance level sections defined based on partitioning an illuminance level range capable of being expressed as an illuminance level of the image sensor; and
a plurality of relations respectively defined with respect to the plurality of illuminance level sections.
9. The operating method of claim 8 , wherein
the plurality of illuminance level sections include a first illuminance level section and a second illuminance level section, the second illuminance level section indicating a higher illuminance level than the first illuminance level section,
the plurality of relations include a first relation defined with respect to the first illuminance level section and a second relation defined with respect to the second illuminance level section, and
when each of the first relation and the second relation is applied to the first dynamic range compression ratio, a value indicated by the first relation is greater than a value indicated by the second relation.
10. The operating method of claim 8 , wherein each relation of the plurality of relations includes a square root term of a dynamic range compression ratio.
11. The operating method of claim 1 , wherein
the first parameters include a first long exposure parameter obtained by multiplying one of the plurality of first exposure times and one of the plurality of first sensor gains together,
the second parameters include a second long exposure parameter obtained by multiplying one of the plurality of second exposure times and one of the plurality of second sensor gains together, and
the generating of the second parameters includes:
calculating the second long exposure parameter based on dividing the first long exposure parameter by the adjustment factor.
12. The operating method of claim 1 , further comprising:
generating second result image data including a plurality of second SDR image data and second HDR image data based on performing the second image capturing.
13. The operating method of claim 12 , wherein the generating of the second result image data includes:
generating the plurality of second SDR image data;
calculating a second dynamic range compression ratio based on a first dynamic range compression ratio and the adjustment factor; and
generating the second HDR image data based on the plurality of second SDR image data and the second dynamic range compression ratio.
14. The operating method of claim 13 , wherein the second dynamic range compression ratio has a value obtained based on multiplying the first dynamic range compression ratio and the adjustment factor together.
15. An image device, comprising:
an application processor configured to
generate first parameters, which are associated with first image capturing and include a plurality of first exposure times and a plurality of first sensor gains, based on first result image data including a plurality of first standard dynamic range (SDR) image data and first high dynamic range (HDR) image data,
generate an adjustment factor based on the first parameters, and
generate second parameters including a plurality of second exposure times and a plurality of second sensor gains based on adjusting the first parameters based on the adjustment factor; and
an image sensor configured to
perform the first image capturing, and
perform second image capturing based on the second parameters.
16. The image device of claim 15 , wherein the application processor is configured to:
generate the plurality of second exposure times and the plurality of second sensor gains based on adjusting the plurality of first exposure times and the plurality of first sensor gains to be inversely proportional to the adjustment factor.
17. The image device of claim 15 , wherein the application processor is configured to:
calculate a first dynamic range compression ratio based on a first setting time and a second setting time among the plurality of first exposure times and a first setting gain and a second setting gain among the plurality of first sensor gains;
calculate a first illuminance level based on the first setting time and the first setting gain; and
calculate the adjustment factor based on the first dynamic range compression ratio, the first illuminance level, and a first adjustment factor relation.
18. The image device of claim 17 , wherein the first dynamic range compression ratio is a value obtained based on dividing a first value by a second value, the first value obtained based on multiplying the first setting time and the first setting gain together, the second value obtained based on multiplying the second setting time and the second setting gain together.
19. The image device of claim 17 , wherein the application processor is configured to:
call the first adjustment factor relation corresponding to the first illuminance level based on an illuminance level-adjustment factor table; and
calculate the adjustment factor based on applying the first adjustment factor relation to the first dynamic range compression ratio.
20. An operating method of an image sensor, the operating method comprising:
generating first result image data including a plurality of first standard dynamic range (SDR) image data and first high dynamic range (HDR) image data based on performing first image capturing;
generating first parameters, which are associated with the first image capturing and include a first long exposure parameter and a first short exposure parameter, based on the first result image data;
generating an adjustment factor based on the first parameters;
generating second parameters including a second long exposure parameter and a second short exposure parameter based on adjusting the first parameters based on the adjustment factor; and
performing second image capturing based on the second parameters,
wherein a ratio of the second long exposure parameter to the second short exposure parameter is calculated to satisfy a hardware constraint of the image sensor for obtaining HDR image data.