Image Processing Formatives
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);
