Development of Image Quality Enhancement of a Digital Camera with the Application of Exposure To The Right Exposure Method

ETTR 노출 방법을 활용한 디지털 카메라의 화질 향상

  • 박형주 (중앙대학교 첨단영상대학원 첨단영상학과) ;
  • 하동환 (중앙대학교 첨단영상대학원 첨단영상학과)
  • Received : 2010.04.06
  • Accepted : 2010.07.22
  • Published : 2010.08.28


Raw files record luminance values corresponds to each pixel of a digital camera sensor. In digital imaging, controlling exposure to capture the first highlight stop is important on linear-distribution of raw file characteristic. This study sought to verify the efficiency of ETTR method and found the optimum over-exposure amount to maintain the first highlight stop to be the largest number of levels. This was achieved by over-exposing a scene with a raw file and converting it to under-exposure in a raw file converting software. Our paper verified the efficiency of ETTR by controlling the exposure range and ISOs. Throughout the results, if exposure increases gradually 6 steps, dynamic range is also increased. And it shows that the optimized exposure value is around + $1\frac{2}{3}$ stop over compared to the normal exposure with the high ISOs simultaneously. We compared visual noise value at $1\frac{2}{3}$ stop to the normal exposure visual noise. Based on the normal exposure's visual noise, we can confirm that visual noise decrement is increased by increasing ISOs. In this experimental result, we confirm that overexposure about + $1\frac{2}{3}$ stop is the optimum value to make the widest dynamic range and lower visual noise in high ISOs. Based on the study results, we can provide the effective ETTR information to consumers and manufacturers. This method will contribute to the optimum image performance in maximizing dynamic range and minimizing noise in a digital imaging.


Digital Camera;ETTR(Exposure To The Right);Raw file;Noise;Dynamic rang;Image quality


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