Abstract
An image sensor has limited dynamic range while the human eye has a logarithmic response over a wide range of light intensity. Although the sensor gain can be set high to identify details in darker areas on an image, this high gain results in saturation in brighter areas. Therefore, gamma correction is essential to match the human eye response. However, the digital gamma correction degrades image quality, especially for darker areas on the image, due to the limited resolution and dynamic range of the analog-to-digital converter (ADC). In this paper, we propose a complementary metal-oxide-semiconductor (CMOS) image sensor (CIS) with a compact nonlinear ADC which performs analog gamma corrections that use the full dynamic range. A CIS with the proposed nonlinear ADC was fabricated with a 0.35-μm CMOS process. The test results show that the analog gamma correction provides a 2. 2dB peak-signal-to-noise-ratio (PSNR) improved image quality, which is better than conventional digital gamma corrections.
| Original language | English |
|---|---|
| Pages (from-to) | 2522-2524 |
| Number of pages | 3 |
| Journal | Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers |
| Volume | 45 |
| Issue number | 4 A |
| DOIs | |
| Publication status | Published - 2006 Apr 7 |
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All Science Journal Classification (ASJC) codes
- Engineering(all)
- Physics and Astronomy(all)
Cite this
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A complementary metal-oxide-semiconductor image sensor with analog gamma correction using a nonlinear single-slope analog-to-digital converter. / Ham, Seogheon; Jung, Wunki; Lim, Seunghyun; Lee, Yonghee; Han, Gunhee.
In: Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers, Vol. 45, No. 4 A, 07.04.2006, p. 2522-2524.Research output: Contribution to journal › Article
TY - JOUR
T1 - A complementary metal-oxide-semiconductor image sensor with analog gamma correction using a nonlinear single-slope analog-to-digital converter
AU - Ham, Seogheon
AU - Jung, Wunki
AU - Lim, Seunghyun
AU - Lee, Yonghee
AU - Han, Gunhee
PY - 2006/4/7
Y1 - 2006/4/7
N2 - An image sensor has limited dynamic range while the human eye has a logarithmic response over a wide range of light intensity. Although the sensor gain can be set high to identify details in darker areas on an image, this high gain results in saturation in brighter areas. Therefore, gamma correction is essential to match the human eye response. However, the digital gamma correction degrades image quality, especially for darker areas on the image, due to the limited resolution and dynamic range of the analog-to-digital converter (ADC). In this paper, we propose a complementary metal-oxide-semiconductor (CMOS) image sensor (CIS) with a compact nonlinear ADC which performs analog gamma corrections that use the full dynamic range. A CIS with the proposed nonlinear ADC was fabricated with a 0.35-μm CMOS process. The test results show that the analog gamma correction provides a 2. 2dB peak-signal-to-noise-ratio (PSNR) improved image quality, which is better than conventional digital gamma corrections.
AB - An image sensor has limited dynamic range while the human eye has a logarithmic response over a wide range of light intensity. Although the sensor gain can be set high to identify details in darker areas on an image, this high gain results in saturation in brighter areas. Therefore, gamma correction is essential to match the human eye response. However, the digital gamma correction degrades image quality, especially for darker areas on the image, due to the limited resolution and dynamic range of the analog-to-digital converter (ADC). In this paper, we propose a complementary metal-oxide-semiconductor (CMOS) image sensor (CIS) with a compact nonlinear ADC which performs analog gamma corrections that use the full dynamic range. A CIS with the proposed nonlinear ADC was fabricated with a 0.35-μm CMOS process. The test results show that the analog gamma correction provides a 2. 2dB peak-signal-to-noise-ratio (PSNR) improved image quality, which is better than conventional digital gamma corrections.
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U2 - 10.1143/JJAP.45.2522
DO - 10.1143/JJAP.45.2522
M3 - Article
AN - SCOPUS:33645681117
VL - 45
SP - 2522
EP - 2524
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 4 A
ER -