SEEM4133 MVS Topic 5 - Quiz 2

Pre-processing methods use a small neighborhood of a pixel in an input image to get a new ______ in the output image.

• coordinate

• brightness value

• color

• textures

Local pre-processing methods can be divided into two groups according to the goal of the processing. The two groups are __________

• smoothing and gradient operators

• smoothie and filtration

• low pass filtering and high pass filtering

• first derivative and an edge detection

Smoothing aims to ________ or other small fluctuations in the image.

• remove all dots

• reduce blurred edges

• suppress noise

• remove dark edges

Averaging with limited data validity _________

• is a technique for removing noise from images while preserving features.

• is a method that assume sharp edges.

• avoid edge blurring by searching for the homogeneous part of the current pixel neighborhood.

• isolate noise points in homogeneous regions with small inverse gradient values.

Averaging according to _______effectively preserves sharp edges, prevents blurring, and removes noise from isolated points within homogeneous regions.

• inverse gradient

• averaging with limited data validity

• statistical principle of noise suppression

• averaging using a rotating mask

___________ avoids blurring by searching for the homogeneous part of the current pixel neighborhood.

• Averaging according to inverse gradient

• Non-linear median filtering

• Median filtering

• Averaging using a rotating mask

Median filtering reduces the blurring of edges. The idea is to replace the current point in the image by ________

• searching for the homogeneous part of the current pixel neighborhood

• the median of the brightness in its neighborhood.

• isolating noise points in homogeneous regions with small inverse gradient values.

• performing averaging only if the computed brightness change of a pixel falls within a pre-defined interval.

Here are examples of homomorphic filters used in image processing EXCEPT .......

• Arithmetic mean

• Harmonic mean

• Geometric mean

• Isometric mean

Which filtering method eliminate impulsive noise quite well?

• Median filter

• Mean filter

• Averaging using a rotating mask

• Averaging according to inverse gradient

Gradient operators have a similar effect as ________

• suppressing high and low frequencies in the frequency domain.

• suppressing high frequencies in the frequency domain.

• suppressing low frequencies in the frequency domain.

• suppressing medium frequencies in the frequency domain.