디지털카메라에서 노출과 렌즈의 종류에 따른 SNR노이즈 변화와 색 재현에 관한 연구

Abstract

When observing the manufacturing companies of the currently released digital cameras, it is an undeniable truth that they have been concentrating on elevating the pixels of the camera in general. Normally, the expressions, 'too much/too little noise' is used when discussing the picture quality. However, this is a wrong expression in the strict sense. It is because what controls the picture quality is not the absolute value of the noise but the relative size with the signal. Even if the absolute value of the noise is however small, when the signal size is small, the corresponding image tends to accompany a great amount of noise. Therefore, the correct expression is the signal to noise ratio being 'high/low.' Amongst the main factors of generating noise, there exists the increase of exposure time, insufficient or exceeding amount of light, focal distance of the lens, high-speed photography and the size of image sensor. SNR noise is the signal to noise that conveys the optical signal of the image sensor and the signal to noise ratio. The amplification of the light guiding sensor, amounts of light and the expression of particles not being smooth but being rough is called the SNR noise.Even with the different amounts of light, when the exposure is adjusted appropriately, the results of the photo is depicted similar but the color reproduction and the noise is differently expressed. Majority of the photographers pay great attention towards adjusting the appropriate exposure but they do not take interest in the point that the noise is generated and the color reproduction differs on the image in accordance with the amount of light and lens. Therefore within the present study, the purpose is placed on clarifying the differences of color reproduction and noise generation of photographed images in accordance with the type of lens (zoom lens and short lens) and the amount of light.