Color Science & Image Fidelity Flashcards

What does 'delta E' (ΔE) measure in display calibration?

Answer: The perceptual color difference between a target and measured color

Delta E quantifies the perceptual difference between two colors; a ΔE of 1.0 is considered the just-noticeable difference threshold for trained observers.

In CIELAB color space, what does the 'L*' axis represent?

Answer: Perceptual lightness from 0 (black) to 100 (white)

L* in CIELAB represents perceptual lightness on a scale of 0 (absolute black) to 100 (perfect diffuse white), designed to be perceptually uniform.

Which HDR standard specifies a peak luminance of 10,000 nits as its reference maximum?

Answer: PQ (SMPTE ST 2084)

SMPTE ST 2084 (Perceptual Quantizer / PQ) defines its electro-optical transfer function with reference to a 10,000 nit absolute peak luminance ceiling.

What is the primary visual artifact caused by insufficient bit depth in a gradient, commonly seen in smooth sky gradients?

Answer: Posterization (banding)

Posterization or banding occurs when insufficient bit depth creates visible steps in a smooth gradient instead of a continuous tonal transition.

What is the purpose of dithering in display signal processing?

Answer: To simulate higher bit depth by randomizing quantization error across pixels

Dithering adds controlled noise to quantization errors, spreading them spatially so the eye integrates them into smoother perceived gradients.

When calibrating a display to Rec. 709 color primaries, which set of primary chromaticities defines the standard?

Answer: R(0.640, 0.330), G(0.300, 0.600), B(0.150, 0.060)

Rec. 709 defines its color primaries at R(0.640, 0.330), G(0.300, 0.600), B(0.150, 0.060) in CIE xy chromaticity coordinates.

What phenomenon causes a display's perceived black level to appear elevated when measuring in a dark room?

Answer: Light leakage or backlight bleed in LCD panels

LCD panels cannot completely block backlight in dark areas, causing light bleed that raises the minimum measurable luminance above true zero.