Image Processing & Enhancement 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 Image Processing & Enhancement flashcards as text
Which histogram equalization technique adapts the contrast enhancement to localized regions of an image rather than the entire image?
Answer: CLAHE (Contrast Limited Adaptive Histogram Equalization)
CLAHE divides the image into tiles and applies histogram equalization locally while limiting contrast amplification to prevent noise over-enhancement.
When applying an unsharp mask for sharpening, what does the 'amount' parameter control?
Answer: The strength of the edge enhancement applied
The 'amount' parameter in unsharp masking controls how strongly the edge detail is boosted relative to the blurred reference image.
A noise reduction filter that replaces each pixel with the middle value of its neighborhood is called a:
Answer: Median filter
The median filter replaces each pixel with the median of surrounding pixels, making it highly effective at removing salt-and-pepper noise while preserving edges.
In frequency domain image processing, what does applying a low-pass filter accomplish?
Answer: Blurs the image by attenuating high-frequency components
A low-pass filter allows low frequencies (smooth tones) to pass while blocking high frequencies (edges and noise), resulting in a blurred image.
Which blending mode in image compositing multiplies the pixel values of two layers, always resulting in a darker image?
Answer: Multiply
Multiply mode multiplies the normalized pixel values of two layers, darkening the result since multiplying values less than 1 always produces a smaller value.
What is the purpose of a 'dust and scratches' filter in image restoration?
Answer: Detects and removes small blemishes by blending with surrounding pixels
The dust and scratches filter identifies small anomalies (spots, lines) and replaces them with interpolated data from surrounding pixel areas.
When performing frequency separation retouching, the low-frequency layer contains:
Answer: Color, tone, and volume information
In frequency separation, the low-frequency layer holds broad tonal variations, color, and volume, while the high-frequency layer holds fine texture details.