Data Analytics Flashcards
7 cards from real DIS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Data Analytics flashcards as text
In digital imaging data analytics, what does a histogram primarily represent?
Answer: The frequency distribution of pixel intensity values
A histogram plots the frequency of each pixel intensity value, revealing tonal distribution across shadows, midtones, and highlights.
Which metric is most useful for quantifying image quality degradation introduced by lossy compression?
Answer: Peak Signal-to-Noise Ratio (PSNR)
PSNR measures the ratio between maximum possible signal power and the power of corrupting noise, making it the standard lossy compression quality metric.
A DIS analyst notices pixel values consistently clipped at 255 across a dataset. What does this indicate?
Answer: Highlight overexposure causing blown-out areas
Pixel values clamped at 255 (the maximum for 8-bit) indicate highlight clipping, meaning detail in bright areas has been lost.
What statistical measure best describes the spread of pixel intensity values in an image?
Answer: Standard deviation
Standard deviation quantifies how widely pixel values deviate from the mean, reflecting the image's contrast and tonal range.
When comparing two imaging systems, System A has lower bias but higher variance. System B has higher bias but lower variance. Which is preferred for consistent batch production?
Answer: System B, because low variance ensures consistency
In production environments, low variance (consistency) is often preferred because systematic bias can be corrected through calibration, while high variance cannot.
Which color model is most appropriate when analyzing perceptual uniformity in digital imaging quality control?
Answer: CIE Lab*
CIE Lab* is designed to approximate human vision's perceptual uniformity, making equal numerical differences correspond to equal perceived color differences.
In a dataset of scanned documents, the signal-to-noise ratio (SNR) is measured at 20 dB. Doubling the SNR in linear terms corresponds to approximately how many dB increase?
Answer: 6 dB
Because SNR in dB = 20·log10(linear ratio), doubling the linear SNR adds 20·log10(2) ≈ 6 dB.