Quantization takes place in digital radiography in which component?

• A. Display monitor
• B. X-ray tube housing
• C. Analog-to-digital converter (ADC)
• D. Worker's control console

Answer: (C)

Quantization is the step where a continuous signal is mapped to a limited set of discrete values. In digital radiography, the detector first captures an analog electrical signal that varies smoothly with the incoming X-ray exposure. The analog-to-digital converter then samples that signal at defined intervals and assigns each sample to the nearest digital value. This process creates the digital image data that can be stored, processed, and displayed. The number of gray levels—and thus how finely the image can represent subtle differences in exposure—is determined by the ADC’s bit depth.

Other components don’t perform quantization: the display monitor renders the digital values as visible light to present the image; the X-ray tube housing generates the X-rays; and the control console adjusts exposure and processing parameters.