Which of the following is NOT an image sensor type?

The correct answer is C, as LED (Light Emitting Diode) is not an image sensor type. Rather, LEDs are a type of light source used for illumination in various applications, including video surveillance to enhance visibility in low-light conditions.

In contrast, both CCD (Charge Coupled Device) and CMOS (Complementary Metal-Oxide-Semiconductor) are well-established types of image sensors used in cameras, including network video cameras. CCD sensors have been traditionally favored for their high image quality and low noise characteristics, while CMOS sensors offer benefits such as lower power consumption and integration capability with other functionalities on a single chip. Both technologies play critical roles in modern imaging systems, with their unique strengths making them suitable for different applications.