ISF Color Science & Image Fidelity 3

Question 1

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

Accepted Answer

The perceptual color difference between a target and measured color

Answer

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

Question 2

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

Accepted Answer

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

Answer

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

Question 3

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

Accepted Answer

PQ (SMPTE ST 2084)

Answer

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

Question 4

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

Accepted Answer

Posterization (banding)

Answer

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

Question 5

What is the purpose of dithering in display signal processing?

Accepted Answer

To simulate higher bit depth by randomizing quantization error across pixels

Answer

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

(ISF) Imaging Science Foundation Certification Practice Test

(ISF) Imaging Science Foundation Certification Practice Test

ISF Color Science & Image Fidelity 3