Which step in digital image processes identifies the useful exposure values in raw image data?

• A. histogram analysis
• B. digitization
• C. LUT adjustments
• D. rescaling

Answer: (A)

Understanding where the meaningful signal lives in the raw data is key. Histogram analysis looks at how many pixels have each intensity value, so you can see where the bulk of the data—the useful exposure values—lies within the detector’s dynamic range. The histogram helps separate signal from noise and guides how the data should be mapped to display values, ensuring the final image preserves contrast where it matters. Digitization is simply converting the analog signal to digital samples, not about locating useful exposure values. LUT adjustments and rescaling come after the useful data is identified: LUTs map the input values to output display values, and rescaling stretches or compresses the range, but the step that identifies the useful exposure values in raw data is histogram analysis.