Spatial filtering

Question 1

Describe spatial filtering.

Answer 1

Linear filtering: convolution

Non-linear filtering.

Question 2

All linear filters.

Answer 2

Smoothing:

• Average filter (geometric/arithmetic mean)
• Gaussian filter
• Adaptive filter (complex)

Sharpening:

• Roberts operators
• Sobel operators
• Laplacian filters

Question 3

All non-linear filters.

Answer 3

• Min/Max
• Median
• Adaptive median (complex)
• Bilinear (replaces the intensity of each pixel with a weighted average of intensity values from nearby pixels)