Image Processing Formatives

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Filtering is a process that removes some unwanted components or small details in an image.

Answer: True

Considering a pixel p in position (x, y), the pixel in the position (x+1, y) is . N4(p) Nd(p) N8(p)

Answer: i and iii

The result of thresholding is a _______________ image.

BINARY

It is represented by a two-dimensional matrix with only 1s and 0s.

BINARY IMAGE

Hard to measure, embodies the achromatic notion of intensity

BRIGHTNESS

The given below equation for getting the difference is called __________.

Backward Difference

This type of image consists of only black and white pixels.

Binary Image

All variables used in Matlab can be observed on _____.

Workspace

Declare the 3x3 matrix below using Matlab. Do not put unnecessary spaces

a = [1 2 4;3 1 3;1 3 4]

Using the order of element in single indexing in Matlab matrices, how would you access the element in row 2 column 3?

a(2,3)

Using the order of the element in single indexing in Matlab matrices, how would you access the element with a value of 5.

a(5)

Matlab will store the result into a default variable named _____.

ans

Write a Matlab command that will resize an image stored in a variable named 'x by half of its size. (do not include unnecessary spaces, end your command with a semicolon)

imresize(x, 0.5); //NOT SURE

We can invert matrices using the ___ function.

inv

Adding a constant value on an image makes image _________.

Brighter

Write a Matlab command the will apply Sobel filter on image img. (do not include unnecessary spaces on your answer, end your command with a semicolon)

Edge(img, 'sobel');

This area allows you to write and edit your Matlab script and save it as you wish.

Editor

This shape value returns a larger matrix of an image than its original.

Full

This image is also known as 8-bit images.

GREYSCALE IMAGE

The given matrix below is an example of

Greyscale Image

Looking into the features that differentiate the objects in an image is under this phase.

Representation and Description

Extracting area or portion of an image that you need is under this phase.

Representation and Description?

A pixel in an N8(p) is considered in Nd(p)

Sometimes

Uses neighborhood pixels values to change the value of the current pixel.

Spatial Filters

An indexed image consists of an image matrix and a color map.

TRUE

Applying gamma value less than one produce a function which is concave downward

TRUE

Applying im2bw in double thresholding is slower than using relational and logical AND because of the extra computation involved

TRUE

As a function, we can add and subtract constant value on an image

TRUE

As discussed, to get the values for the pixel located on the edges, we can do two things.

TRUE

As humans, we can identify and classify images in an instant

TRUE

Assuming m is an image. We can get its complement by performing the operator 1-m

TRUE

By applying arithmetic operation on an image, we may encounter loss of information.

TRUE

By plotting the pixels values, we can observe how the pixels shifted by adding and subtracting a constant.

TRUE

By using the 'full' as a value for shape parameter, returns a result larger than the original.

TRUE

Color model facilitates the specification of colors in some standard and generally accepted way.

TRUE

Compression can be also applied to audio files and video

TRUE

Compression decreases the chances of the error transmission

TRUE

Cyan is a primary color of pigments

TRUE

Detail removal in an image is applicable for measurement or counting purposes.

TRUE

Edge enhancement may also be called unsharp masking.

TRUE

Edges contain some of the most useful information in an image.

TRUE

Elements in matrices in matlab may have different numeric data types.

TRUE

Finding lines, circles, or shapes in an image is an example of image segmentation.

TRUE

Given a binary image with row values of 1 0 0 1 1 1 1 1, the encoded value after applying RLE is 1145 using the alternative method discussed.

TRUE

Greyscale images can be transformed into a sequence of binary images by breaking them up into their bit-planes.

TRUE

High pass filters can be used in edge detection and edge enhancement.

TRUE

Histogram equalization automatically distributes the gray levels on an image.

TRUE

In an image with four distinct level intensities, the intensity that has the highest frequency receives the largest bits of the code

TRUE

In the CMY model cyan is the negative of red in RGB which can be calculated as 1 - R.

TRUE

It is convenient to describe a linear filter simply in terms of the coefficients of all the grey values of pixels within the mask.

TRUE

Lossless compression is a group of data compression algorithms that permits the original data to be accurately rebuilt from the compressed data

TRUE

Lossy compression is the family of data encoding method that utilizes imprecise estimates to represent the content

TRUE

Matlab is programming platform designed specifically for engineers and scientists.

TRUE

Motion blur may be observable when taking a photo of "fast-moving" objects.

TRUE

Motion blur may be observable when taking a photo of fast-moving objects.

TRUE

One of the applications of thresholding is remove varying background from a text.

TRUE

Our visual system tends to undershoot or overshoot around the boundary of regions of different intensities.

TRUE

Single and double thresholding is an example of global thresholding

TRUE

Spatial resolution pertains to the density of pixels/

TRUE

The RGB model is based on cartesian coordinate system.

TRUE

The YIQ is a recording of RGB for color television.

TRUE

The display of the result of a command whose output is a matrix of type double can be greatly affected by a judicious choice of a scaling factor.

TRUE

The first byte in RLE represents the number of characters in the sequences

TRUE

The histogram is a graphical representation intensity distribution of an image.

TRUE

The im2bw function automatically scales the value level to a grey value appropriate to the image type and then performs thresholding by our first method.

TRUE

The inter-pixel redundancy is a result from the correlation between the pixels of an image

TRUE

The level parameter in the im2bw function is a value between 0 and 1.

TRUE

The lower the resolution, the pixelization increases.

TRUE

The repeating string on RLE is called run counts

TRUE

The right most bit represents the least significant bit.

TRUE

There is permanent loss in information in lossy compression

TRUE

Threshold is some fixed value which draws a boundary line between two set of data.

TRUE

Thresholding can be used as preprocessing to extract an interesting subset of image structures which will then be passed along to another operator in an image processing chain.

TRUE

Thresholding converts a grayscale image into a binary image

TRUE

True color images are also called 24-bit color images.

TRUE

Two pixels p and q with values from V are 4-adjacency if q is in the set N4(p).

TRUE

Two pixels p and q with values from V are 8-adjacency if q is in the set N8 (p).

TRUE

We can consider an edge as a line of pixels showing an observable difference

TRUE

We can consider an edge as a line of pixels showing an observable difference.

TRUE

We can create our own function to perform piecewise linear stretching.

TRUE

We can form the differences, by subtracting each value from its successor of grey values of pixels in a line crossing an edge.

TRUE

We can remove unnecessary details from an image using thresholding

TRUE

We can think of a pixel value that maps itself to values 0 to 255 in a grayscale image.

TRUE

We can use the relational operator to do thresholding in Matlab.

TRUE

We may use edges to measure the size of objects in an image and isolate the from their background.

TRUE

We perform detail removal to measure or observe object without being distracted by unnecessary detail.

TRUE

We use image processing to improve image information for human interpretation

TRUE

We use image processing to render image more suitable for autonomous machine perception

TRUE

You can type all your commands in the command window.

TRUE

Zero crossings has a value of zero and are between negative and positive valued pixels.

TRUE

RGB Images are called ________.

TRUE COLOR IMAGE

This image contains three colormap values

TRUE COLOR IMAGE

It is a simple segmentation method yet powerful.

Thresholding

It is a set of programs in Matlab that is designed to support a specific task.

Toolbox

It processes the image as a single block.

Transforms

A pixel in an N4(p) is considered in N8(p).

True

An image can be considered as a two-dimensional function, where the function values give the brightness level of the image at any given point.

True

An image is captured by a hardware sensor based on the amount of light it emits.

True

Applying the command imadjust(img, [], []) does nothing to the image img.

True

As humans, we do not perceive grey levels as they are, but rather as they differ from their surroundings.

True

As humans, we rely on our vision to understand the world around us.

True

As the bit plane reaches to most significant bit, the information on the image becomes clearer.

True

Before doing thresholding on an image, we need first to observe its grey values to get the desired value for T.

True

Cyan is a secondary color of light

True

Filtering is a process that removes some unwanted components or small details in an image

True

Ignoring the pixel values on edges will give us an output image which is smaller than the original.

True

Image thresholding is a simple segmentation method yet powerful.

True

Image thresholding is one of the simplest methods to separate regions which are higher than the set threshold

True

Matlab stores the full values any computation.

True

Spatial filters are considered as an image processing technique under image enhancement.

True

The dark image has a histogram where gray levels shifted on the left.

True

The filter2 function produces a matrix of equal size to the original image matrix and uses zero paddings as default.

True

The higher the resolution, the larger the image file size

True

The result of filter2 function in Matlab is a matrix of data type uint8.

True

Thresholding converts a grayscale image into a binary image.

True

Thresholding method is a technique that uses the classification pixels to segment colored and grayscale images.

True

Using threshold on an image may reveal additional information which is not observable by our naked eye.

True

We can also lighten and darken an image using multiplication and division.

True

With Matlab, we can only analyze data but not develop our own algorithms.

True

The most common grayscale image datatype.

Uint8

To ignore the edges, we set the shape parameter of filter2 function to ________.

Valid

In a 240 x 240 image, what is the file size in bytes for a true-color image?

172800

Given the colors below, how many of them belong to the secondary color of pigments. Red, Green, Black, White

2

Using the single indexing, what is the 8th element of a'

2

Given the output below, determine what is the grayscale value of the red channel.

203

In true-color images, the number of bits required to represent a pixel is _____. (answer in integer only)

24

In greyscale images, the level of grey ranges from ____ to ___. (answer in integers only)

255 to 0

How many grey levels are there in an 8-bit image

256

The difference tends to enhance edges and reduce other components. We have ____ ways to do

3

Given the string 'AAABBBCCC' what is the new string value after applying the RLE? (write your answer in one string do not include spaces, use the traditional method we discussed in the lecture)

3A3B3C

Given an image with a 5x5 resolution, applying a 3x3 mask will produce a result _____ of number of new pixel values.

3X3

What is the default size of the command fspecial('average');

3X3

Assuming that we have the current pixel represented in yellow on the given image, what pixel in green is its ____________ neighborhood.

5 x 7

In a 240 x 240 image, what is the file size in bytes for a greyscale image?

57600

Using the command fspecial('average',5) will give us a filter with size _____.

5x5

What is the value in row 1 column 1 if matrix a is flipped using fliplr?

7

What is the value in row 1 column 1 if matrix a is flipped using rot90?

7

In a 240 x 240 image. what is the file size in bytes for a binary image?

7200

Given an image with a 5x5 resolution, applying a 3x3 mask will produce a result of ___ number of new pixel values.

9

This operator generates a vector of values from a to b. (answer using the symbol only)

: // colon

We put this symbol to suppress output on the command window.

;

Matlab prompt is denoted by this symbol.

>>

How do you run the following in Matlab? Filename: myscript.m Location: C:\Users\Gwapo\Desktop

>run("C:\Users\Gwapo\Desktop\myscript.m")

Which of the following is correct about Matlab. 1. Matlab can visualize data 2. Matlab can analyze data 3. Matlab is designed to support matrices and its operations 4.Matlab can create models

ALL OF THE GIVEN

What is the correct way to access an element in a 4x4 matrix?

M(2,3)

Combining the first two steps into one will produce a Laplacian of Gaussian or LoG.

MARR-HILDRETH

It is a shape over an image, usually in a rectangular form.

MASK

Inspecting and interpreting images obtained from X-rays, MRI or CAT scans, and analysis of cell images are an example of the application using image processing under ___________.

MEDICINE

It occurs when the shutter speed of the camera is too long for the speed of the object.

MOTION BLUR

To get the most significant bit, which command we should use on a grayscale image img?

Mod(floor(img/128),2);

The complement of a grayscale image is its photographic ______________.

NEGATIVE

Given a pixel X, the other pixels that surround X is called ____________,(type your answer in lowercase)

NEIGHBORHOOD

The function _______________ applies a filter to an image according to a pre-defined function.

Nlfilter

It is a random error when capturing an image

Noise

Picture elements are also known as ________.

PIXELS

Isaac Newton first passed white light through a ________ and watched it fan out into a rainbow, he identified seven constituent colors.

PRISM

Simples but the most powerful and widely used technique in image processing.

Point Operations

Image enhancement is under this phase of image processing.

Preprocessing

This phase performs a basic task to make an image suitable for the major part of image processing.

Preprocessing

This term refers to the number of total pixels

RESOLUTION

Assigning labels to the selected features and meaning to it is what phase.

Recognition and Interpretation

Displays the value of the pixel at the bottom of the display.

impixelinfo

This function allows you to read image in Matlab.

imread

Create a 3x3 matrix full of 0s using a Matlab function

zeros(3)

Create a 3x3 matrix full of 0s using a Matlab function. (do not include spaces)

zeros(3)

To complement a binary image, we may use ________.

~m

write a Matlab command to read an image named 'samplg.png' (do not include unnecessary spaces, use semicolon at the end of vour command

>>imread('sample.png');

Given the 3x3 mask matrix below, using the notation discussed in our module, what is the coefficient of h?

-2

What is the value in row 2 column 2 if matrix a is reshaped using reshape(a, 2, 8)?

-7

If we want to get the product of two matrices element-wise then we use what operator (answer using the symbol only)

.

In padding values on the edges of an image, we assume that all necessary values outside the image are .

0

The uint8-restricts values to integers between __ and __

0, 255

what is the result of the command 1:2:10? (use only spaces to separate your the values in your answer)

1 3 5 7 9

Given the mask filter f=[-1 -1 -1;-1 z -1;-1 -1 -1]/9; what value of z will give us a result same as using fspecial('unsharp',0.5);

11

Given the image matrix, determine the resulting pixel value of the 3x3 linear averaging filter. (round off your answer to the nearest whole number)

111

An index image may also refer as

Channel or map

This window is where you enter your commands in Matlab.

Command window

Which is not a primary color of light.

Cyan

Subtracting a constant from an image ______ the image.

Darkens

Applying the command imadjust(img, [], []) darkens the image img.

FALSE

Applying the function y = x/2 lightens up an image.

FALSE

Blur is a common problem in data transmission

FALSE

Cyan is a secondary color of pigments.

FALSE

Gaussian filters are a class of high-pass filters, all based on the Gaussian probability

FALSE

Given the bit-planes of the original grayscale image below, c0 represents the most significant bit.

FALSE

Histogram stretching does not require any user input.

FALSE

Huffman is most use in bitmap files

FALSE

Ignoring the pixel values on edges will give us an output image with same size with the original.

FALSE

Image compression is the process of converting an image file in such a way that it consumes the same space as the original file

FALSE

Improving image contrast, or brightening an image is an example of image segmentation.

FALSE

In an image with four distinct levels of intensities, the intensity that has the highest frequency receives the least bits of the code.

FALSE

In padding values on the edges of an image, we can randomly select values for all necessary values outside the image.

FALSE

Noise removal is an example of image segmentation

FALSE

Objects extracted from the background are always in color white.

FALSE

Our perception of an image as humans starts with recognizing and interpreting it with the visual cortex in our brain.

FALSE

RLE and Hulfman are both lossy compression algorithms

FALSE

Robert cross-gradient filter is an example of second differences filters.

FALSE

The im2bw function can only be used for type of double.

FALSE

The pixels surrounding a given pixel is called picture elements.

FALSE

To do double thresholding, we need to select a value for T that will serve as threshold value wherein all pixel values greater than T will turned into black and white for the rest(or vice versa)

FALSE

We can create binary data from a grayscale image using logical operators such as >, <, and ==

FALSE // =

Finding lines, circles, or shapes in an image is an example of image enhancement.

FALSE // IMAGE SEGMENTATION

We perform noise removal to measure or observe object without being distracted by unnecessary detail

FALSE //DETAIL REMOVAL

It creates a figure on the screen. A figure is a window in which a graphics object can be placed.

FIGURE

The imadjust is a function in Matlab that allows us to add a constant value on an image.

FLASE

An 8-bit color image has a size of 25 bytes

False

Dark image has a histogram where gray levels shifted on the right

False

High pass filters are effective in smoothing an image.

False

Histogram equalization allows us to isolate objects from the background.

False

Histogram stretching allows us to isolate objects from the background.

False

Hue is measure in lumens

False

Noise may be observable when taking a photo of fast-moving objects

False

The im2bw function can only be used for type of double

False

The threshold value is automatically selected by the Matlab.

False

To ignore the edges, we set the shape parameter of the filter2 function to the value 'same'.

False

We can perform an arithmetic operation on two matrices with different dimensions in Matlab.

False

We can use low pass filters to sharpen an image.

False

The imadjust function is designed to work equally well on images of type double only.

FalseA

Which among the following is correct regarding image filters? I. Filters are used for image enhancement II. Filters are used for image restoration III. Filters are used for image restoration, but not for image enhancement IV. Filters are used for image enhancement, but not for image restoration

I and II

Which of the following is true on the command a:b 1. a should be less than or equal to b 2. a maybe greater than to b 3. b is always greater than or equal to a 4.b may be less than a

I and III only

The first step to calculate the spatial filters is to position the mask over the current pixel. I. form all products of filter elements with the corresponding elements of the neighborhood ii. position the mask over the current pixel iii. add up all the products

II

It is a way to make image appear sharper and more pleasing to the human eye. Best observed on the printed page.

IMAGE ENHANCEMENT

sharpening or deblurring an out of focus image, highlighting edges, improving image contrast, or brightening an image, removing noise.

IMAGE ENHANCEMENT

It refers to processing an image so that the result is more suitable for an application.

IMAGE Enhancement

removing of blur caused by linear motion, removal of optical distortions

IMAGE RESTORATION

Finding lines, circles, or particular shapes in an image, in an aerial photograph, identifying cars, trees, buildings, or roads.

IMAGE SEGMENTATION

This involves subdividing an image into constituent parts, or isolating certain aspects of an image.

IMAGE SEGMENTATION

The image has a direct mapping of pixel to its colormap values

INDEXED IMAGE

Using image processing for automating inspection process is an example of its applications under ______________________.

INDUSTRY

This phase of image processing captures the scene that we want to process.

Image Acquisition

Removing motion blur in an image is under this aspect of image processing.

Image Restoration

This may be considered as reversing the damage done to an image by a known cause

Image Restoration

Display the info about image

Imfinfo

Convert an image to grayscale

Ind2gray

This Matlab function converts index image to grayscale.

Ind2gray

This image has a direct mapping of pixel to its colormap values.

Indexed Image

It is the perceived amount of energy from a light source.

LUMINANCE

Specify the coordinate system and a subspace within that system where each color is represented by a single point

color space

Write a Matlab command that will apply the Prewitt filter on image img. (do not include unnecessary spaces on your answer, end your command with a semicolon)

edge(img, 'prewitt');

Write a Matlab command that will apply zero-crossing on image named 'img' with Laplace named 'lap'. (do not include unnecessary spaces on your answer, end your command with semicolon)

edge(img, 'zerocross', lap);

Magenta is the opposite of red color in the primary colors of light

false

Thresholding converts a binary image into a grayscale image.

false

To obtain the values same as the indexing of pixel info, we can use ___________. (answer in function name only)

figure_name

we can create our own filters using this function.

fspecial

Write a command using fspecial function that will create an average linear filter with size 3 by 4. (do not include unnecessary spaces in your answer)

fspecial("average", [3,4])

fspecialWrite a Matlab command that uses fspecial implements unsharp filter with an alpha value of 0.5 (do not include unnecessary spaces on your answer, end your command with a semicolon).

fspecial('unsharp',0.5);

it does this by padding with zero, and applying the filter at all places on and around the image where the mask intersects the image matrix

full

The Matlab code str2double('123') is an example of ________________.

function

Given the binary equivalent of pixel intensity, what is the least significant bit? (answer using the letter that represents the bit)

h

This filter eliminates the low intensity values.

high pass filter

Matlab function that allows us to perform histogram equalization. (answer only using the function name)

histeq

It is used to observe and enhance image contrast. (Answer in lowercase, one word only)

histogram

It is a Matlab function that converts HSV image to RGB color model. (answer using the function name only. do not include parenthesis)

hsv2rgb

Considering a pixel p in position (x, y), the pixel in the position (x+1, y) is . i. N4 (p) ii. Nd (p) iii. N8 (p)

i and iii

Matlab function that allows us to perform thresholding. (answer using only the function name)

im2bw

Using the built-in Matlab function, apply a threshold on image img with a threshold value of 0.23(do not include unnecessary spaces on your answer, and you command with semicolon)

im2bw(img,0.23)

Function in Matlab allows us to add a constant value to an image. (answer using the function name only)

imadd

Using the Matlab function. How can we add a constant value 128 to a image variable named 'img'? (do not include unnecessary spaces in your answer, end your answer with semicolon)

imadd(img,128);

A function in Matlab that allows us to perform histogram stretching

imadjust

It passes over the low-frequency components and reduces or eliminates high-frequency components.

low pass filter

If you want to save a Matlab script for future use, you may save it with a file extension dot ____. (answer the letter only)

m

The order of element in single indexing access in Matlab corresponds to _____________.

m( i + r ( j - 1 ))

These are pixels surrounding a given pixel.

neighborhood

This Matlab function converts RGB image to grayscale.

rgb2gray

It is a Matlab function that converts the RGB image to the HSV color model. (answer using the function name only, do not include parenthesis)

rgb2hsv

It is a Matlab function that converts the RGB image to the YlQ color model. (answer using the function name only. do not include parenthesis)

rgb2ntsc

We can use to get the number of rows and columns on an image.

size

Assign the result of 2+1 in a variable named 'sum'.

sum=2+1

Each row of the color map specifies the red, green, and blue components of a single color.

true

Image thresholding are used to enhance images.

true

We can consider edges as sudden changes of discontinuities in an image.

true

Assuming image img is in double datatype, how you will convert it to uint8? (do not include unnecessary spaces, end your command with semicolon)

uint8(img);


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