Image Representation in Computer Science

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Questions and Answers

A digital image can be considered as a discrete representation of data possessing both spatial and intensity

colour

The two-dimensional (2-D) discrete, digital image I (m,n) represents the response of some sensor at a series of fixed positions in 2-D Cartesian

coordinates

The individual picture elements or pixels of the image are referred to by their 2-D (m, n)

index

The conversion from a set of numbers to an actual image is achieved through a ______ map.

colour Signup and view all the answers

The most common colour map is the ______, which assigns all shades of grey from black to white according to the signal level.

greyscale Signup and view all the answers

In certain instances, it can be better to display intensity images using a ______ map.

false-colour Signup and view all the answers

False colour can also serve to delineate certain features or structures, making them easier to identify for the human ______.

observer Signup and view all the answers

The resolution of an image source can be specified in terms of three quantities: Spatial resolution, Temporal resolution, and ______ resolution.

quantization Signup and view all the answers

Match the following image attributes with their definitions:

Spatial resolution = The dimensions of the image in terms of pixels Temporal resolution = Number of images captured in a given time period False-colour map = Assigns colours to numerical values in an image Greyscale = Assigns shades of grey from black to white according to the signal level Signup and view all the answers

Match the following image types with their descriptions:

Intensity image = Contains a single numerical value at each pixel location True colour image = Represents the full spectrum of colours as a triplet vector at each pixel location Digital image = Discrete representation of data possessing both spatial and intensity Astronomical image = Often displayed using false-colour maps to highlight structure and finer detail Signup and view all the answers

Match the following terms related to image display with their meanings:

Greyscale (left) = Displays an astronomical intensity image using shades of grey from black to white False colour (right) = Displays an astronomical intensity image using non-grey colours to highlight certain features or structures Jet colour map = Used to highlight the structure and finer detail of an astronomical intensity image using a linear colour scale Colour map = Assigns specific shades of colour to each numerical level in an image Signup and view all the answers

Match the following attributes of an image source with their explanations:

Column by row dimensions = Defines the number of pixels used to cover the visual space captured by the image Continuous capture system = Captures a specified number of images in a given time period Video frame = An individual image captured in a video sequence Resolution = Defines the representational power of an image Signup and view all the answers

Match the following statements about false-colour images with their reasons for usage:

Enhances human sensitivity to colour = Uses non-grey colours to represent intensity, as human visual system is more sensitive to colour than shades of grey Highlights specific features or structures = Makes it easier for human observers to identify certain elements in images Commonly used in medical and astronomical images = Due to its ability to highlight details and structures that may not be easily discernible in greyscale Signup and view all the answers

Match the following image processing terms with their definitions:

Spatial resolution = The level of detail in an image, determined by the number of pixels Temporal resolution = The number of frames per second in a video Discretization = The process of converting a continuous signal into a discrete signal Intensity map = A representation of pixel intensity values in an image Signup and view all the answers

Match the following terms related to image representation with their descriptions:

Digital image = A discrete representation of data with spatial and intensity information Pixel = The smallest element of an image, defined by its 2-D index Image origin = The reference point for the positioning of pixels in an image Cartesian coordinates = A system for locating points in a plane using distances from two perpendicular lines Signup and view all the answers

Match the following concepts in MATLAB® with their meanings:

I(m,n) = The response of a pixel located at the mth row and nth column in an image, according to MATLAB® convention Column–row convention = An alternative method for designating rows and columns in an imaging system Top-left image origin = The starting point for the positioning of pixels in an image, as per MATLAB® convention Sampling process = The procedure for converting a continuous spatial signal into a discrete digital image Signup and view all the answers

Match the following image types with their characteristics:

False colour = Assigning artificial colors to represent grayscale levels for easier feature identification Standard image types = Common categories of images, such as binary, grayscale, and color images Multidimensional signal = Treating an image as a complex signal with spatial and intensity dimensions Colour map = A scheme for assigning colors to represent intensity levels in an image Signup and view all the answers

Match the following terms related to Omar Al-Mukhtar University's Computer Science Department with their descriptions:

Image Processing #1 = A specific course covering the fundamental concepts of representing and processing digital images Dr Tahani Almabruk = The instructor responsible for teaching Image representation and related topics Al-Beyda/ Libya = The location of Omar Al-Mukhtar University's Computer Science Department 2-D Cartesian coordinates = A system for graphing points on a two-dimensional plane using x and y axes Signup and view all the answers

Study Notes

Digital Image Representation

Digital images are discrete representations of data with spatial and intensity information.
A 2-D digital image I(m,n) shows sensor responses at fixed 2-D Cartesian positions.
Individual image elements are pixels, identified by their 2-D coordinates (m, n).
Image conversion from numbers to a visual image uses a color map.

Color Maps and Image Display

The most common color map is grayscale, assigning shades of gray based on signal levels.
Intensity images might benefit from alternative color maps in specific cases.
False color enhances feature visibility for easier human identification.

Image Resolution

Image resolution involves spatial, temporal, and spectral resolution.

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Description

Test your knowledge about the representation of images in computer science, including basic notation, image types, and formats. Explore the concept of digital images as a discrete representation of data with spatial and intensity information.