Image Enhancement and Spatial Filtering Quiz

What is the process of replacing a pixel with a value based on some operations or functions in image processing?

• Filtering

• Enhancement

• Smoothing

• Averaging

Which type of filter is used to eliminate or attenuate high frequency components in the frequency domain?

• Median filter

• Band-pass filter

• High-pass filter

• Low-pass filter

What is the visual effect of a low-pass (smoothing) spatial filtering?

• Enhanced edges on a dark background

• Reduced noise but blurred edge

• Remove selected frequency regions

• Highlight fine detail

What is the principal approach in defining a neighborhood about a point (x,y) in spatial filtering?

• Use a circular neighborhood

• Use a triangular neighborhood

• Use a rectangular neighborhood

• Use a subimage area centered at (x,y)

Which type of filter is used primarily for noise reduction and eliminates isolated spikes?

• Low-pass filter

• Median filter

• High-pass filter

• Band-pass filter

What is the most important property of the median in order statistics filters?

• Less sensible to noise than mean

• Can be computed in O(n)

• Not an element of the original set of values

• Sensible to noise than mean

What is the visual effect of a high-pass (sharpening) spatial filtering?

• Remove selected frequency regions

• Highlight fine detail

• Reduced noise but blurred edge

• Enhanced edges on a dark background

What is the purpose of using order-statistic filters in image processing?

• Highlight fine detail

• Suppress noise

• Remove selected frequency regions

• Eliminate isolated spikes

What is the outcome of applying a median filter to an image?

• The gray level of each pixel is replaced by the minimum of the gray levels in the neighborhood

• The gray level of each pixel is replaced by the median of the gray levels in the neighborhood

• The gray level of each pixel is replaced by the average of the gray levels in the neighborhood

• The gray level of each pixel is replaced by the maximum of the gray levels in the neighborhood

What is the purpose of directional smoothing in image processing?

• Avoid filtering across edges

• Use more explicit edge detection and adapt filtering accordingly

• All of the above

• Compute spatial average along several directions