Digital Image Processing Exam

Which of the following can be done by point processing?

• Darken image

• Negative image

• All of other options

• Brighten image

Histogram equalization is mainly used for...

• Making an existing image brighter

• Improving contrast of an existing image

• Making an existing image darker

• Reducing contrast of an existing image

Given that “img” is an 2D array of float grayscale values from 0.0 to 1.0. Insert a line into the blank in Python to reduce the global brightness of the image? (We will perform clipping after the loops.)

• img[y][x] -= 0.5

• img[y][x] *= 0.5

• img[y][x] /= 0.5

• img[y][x] += 0.5

What is the order of main steps when performing frequency filtering?

• Preprocessing, Filter, Inverse Fourier transform, Post processing, Fourier transform

• Preprocessing, Filter, Fourier transform, Post processing, Inverse Fourier transform

• Preprocessing, Fourier transform, Filter, Inverse Fourier transform, Post processing

• Preprocessing, Inverse Fourier transform, Filter, Fourier transform, Post processing

The dilation operation can be used to...

• All of other choices

• Fill small holes inside objects

• Join very near objects

• Make objects bigger

High pass filter is to...

• Eliminate both low frequency components and high frequency components

• Eliminate low frequency components and keep high frequency components

• Eliminate high frequency components and keep low frequency components

• Keep both low frequency components and high frequency components

For each pixel in the input image, what is point processing?

• An operation that takes that pixel and produces one output pixel

• An operation that takes that pixel with some neighbor pixels and produces some output pixels

• An operation that takes that input pixel and produces some output pixels

• An operation that takes that pixel with some neighbor pixels and produces one output pixel

Why do we have optical illusions?

• Because our brain interprets images based on adaptive visual cues

• Because our eyes cannot see diagonals, vertical and horizontal lines at the same time

• None of the other answers

• Because our eyes cannot distinguish between different shadow levels

A grayscale digital image is

• A 3D matrix of discrete picture elements

• A 2D matrix of discrete picture elements

• A 2D matrix of continuous picture elements

• A 1D vector of continuous picture elements

High frequency components mainly contain information about ...

• The detail of objects

• The color of objects

• The shape of objects

• The brightness of objects