Traditional Culture Encyclopedia - Photography and portraiture - Which is better, the ICR infrared filter in the surveillance camera or the electronic color turning black?

Which is better, the ICR infrared filter in the surveillance camera or the electronic color turning black?

If it is explained from the aspect of spectral filtering, the pure ICR filter will have better color conversion function for black and white and low illumination, and there will be less noise. Because everyone has a certain understanding of infrared wavelength, it is defined as the band between 300 nm and 850 nm, which can be detected by CCD. Because of its infrared sensitivity, the image clarity of the camera is far less realistic than that of the human eye. Infrared rays mixed with visible light (human eye detection standard) will interfere with the color and tone of the image, resulting in chromatic aberration.

ICR filter is an improvement on the fidelity of imaging color. By placing a filter with a special coating in front of the camera CCD, the infrared band that interferes with imaging color is filtered out. However, at present, many infrared cameras on the market only use high-sensitivity filters, so that both infrared rays and far-infrared rays can enter the lens, and the picture color distortion is serious, showing a serious redness phenomenon (shooting human skin, showing a red effect). So gun cameras and high-end color cameras use real ICR filters. In order to restore normal light, the color tone should be as consistent as possible with the human eye.

The principle of electronic turning black is that the lens and CCD do not filter, but do arithmetic filtering in the DSP chip to remove the part with frequency lower than visible light (high frequency band) and higher than infrared band (low frequency band), which leads to the large noise particles in the picture and is still unclear under low illumination. In the process of filtering, it is inevitable that some frequency band signals will be filtered uncleanly and excessively, and the picture will appear uncoordinated. Just like the optical zoom and electronic zoom of a camera.

So to sum up, the effect of ICR infrared filter is definitely better than that of color-to-black electronic filter. It is a real low illumination effect, not a "made" effect.