Image sensor and digital gain compensation method thereof
View Patent ↗An image sensor and digital gain compensation thereof. The image sensor includes a variable amplification device for amplifying an inputted analog image signal as a variable first gain value, an analog-to-digital conversion unit for converting the amplified analog image signal into a digital image signal, and a digital gain compensation device for comparing the first gain value with a reference gain value and compensating the digital image signal as a digital second gain value when the first gain value is less than the reference gain value.
1. An image sensor, comprising:
a variable amplification means for amplifying an input analog image signal as a first gain value;
an analog-to-digital conversion means for converting the amplified analog image signal into a digital image signal; and
a digital gain compensation means for comparing the first gain value with a reference gain value and compensating the digital image signal as a digital second gain value responsive to the first gain value being less than the reference gain value.
2. The image sensor of claim 1 , wherein the reference gain value is approximately 1.
3. The image sensor of claim 1 , wherein the digital gain compensation means performs a multiplication operation.
4. The image sensor of claim 1 , wherein the first gain value ranges from approximately 0.5 to approximately 2.5.
5. The image sensor of claim 1 , wherein the image signal is in a format of red, green and blue (RGB).
6. The image sensor of claim 1 , further including a pixel array unit for outputting the analog image signal.
7. The image sensor of claim 1 , further including an image signal processing means for receiving the compensated digital image signal and adjusting color interpolation, color calibration, gamma calibration, automatic white balance and automatic exposure.
8. A method comprising:
amplifying an input analog image signal as a first gain value;
converting the amplified analog image signal into a digital image signal;
comparing the first gain value with a reference gain value; and
compensating the digital image signal as a second gain value in response to the first gain value being less than the reference gain value.
9. The method of claim 8 , wherein the reference gain value is approximately 1.
10. The method of claim 8 , further comprising outputting the digital image signal responsive to the first gain value being greater than the reference gain value.
11. The method of claim 9 , wherein the first gain value ranges from approximately 0.5 to approximately 2.5.
12. An image sensor, comprising:
a variable amplification unit configured to amplify an input analog image signal as a first gain value;
an analog-to-digital converter configured to convert the amplified analog image signal into a digital image signal; and
a digital gain compensation unit configured to compare the first gain value with a reference gain value and compensate the digital image signal as a digital second gain value responsive to the first gain value being less than the reference gain value.
13. The image sensor of claim 12 , wherein the reference gain value is approximately 1.
14. The image sensor of claim 12 , wherein the second gain value is obtained by dividing the reference gain value by the first gain value.
15. The image sensor of claim 12 , wherein the digital gain compensation unit is configured to perform a multiplication operation.
16. The image sensor of claim 12 , wherein the first gain value ranges from approximately 0.5 to approximately 2.5.
17. The image sensor of claim 12 , wherein the image signal is in a format of red, green and blue (RGB).
18. The image sensor of claim 12 , further including a pixel array unit configured to output the analog image signal.
19. The image sensor of claim 12 , further including an image signal processor configured to receive the compensated digital image signal and adjust color interpolation, color calibration, gamma calibration, automatic white balance and automatic exposure.