This document discusses image enhancement techniques in the spatial domain. It defines spatial domain processing as the direct manipulation of pixel values, as opposed to frequency domain processing which modifies the Fourier transform. The key techniques discussed are:
- Linear and non-linear transformations which map input pixel values to new output values.
- Spatial filters which operate on neighborhoods of pixels, including smoothing filters to reduce noise and sharpening filters to enhance edges.
- Histogram processing techniques like equalization to improve contrast in low contrast images.
The document provides examples of each technique and discusses their applications in image enhancement.
Digital image processing is the use of computer algorithms to perform image processing on digital images. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing.
COM2304: Intensity Transformation and Spatial Filtering – III Spatial Filters...Hemantha Kulathilake
At the end of this lecture, you should be able to;
describe sharpening through spatial filters.
Identify usage of derivatives in Image Processing.
discuss edge detection techniques.
compare 1st & 2nd order derivatives used for sharpening.
Apply sharpening techniques for problem solving.
Digital image processing is the use of computer algorithms to perform image processing on digital images. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing.
COM2304: Intensity Transformation and Spatial Filtering – III Spatial Filters...Hemantha Kulathilake
At the end of this lecture, you should be able to;
describe sharpening through spatial filters.
Identify usage of derivatives in Image Processing.
discuss edge detection techniques.
compare 1st & 2nd order derivatives used for sharpening.
Apply sharpening techniques for problem solving.
COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...Hemantha Kulathilake
At the end of this lesson, you should be able to;
describe spatial domain of the digital image.
recognize the image enhancement techniques.
describe and apply the concept of intensity transformation.
express histograms and histogram processing.
describe image noise.
characterize the types of Noise.
describe concept of image restoration.
Histogram Processing
Histogram Equalization
Histogram Matching
Local Histogram processing
Using histogram statistics for image enhancement
Uses for Histogram Processing
Histogram Equalization
Histogram Matching
Local Histogram Processing
Basics of Spatial Filtering
Here in the ppt a detailed description of Image Enhancement Techniques is given which includes topics like Basic Gray level Transformations,Histogram Processing.
Enhancement using Arithmetic/Logic Operations.
image averaging and image averaging methods.
Piecewise-Linear Transformation Functions
Histogram equalization is a method in image processing of contrast adjustment using the image's histogram. Histogram equalization can be used to improve the visual appearance of an image. Peaks in the image histogram (indicating commonly used grey levels) are widened, while the valleys are compressed.
Image Enhancement: Introduction to Spatial Filters, Low Pass Filter and High Pass Filters. Here Discussed Image Smoothing and Image Sharping, Gaussian Filters
A Comparative Study of Histogram Equalization Based Image Enhancement Techniq...Shahbaz Alam
Four widely used histogram equalization techniques for image enhancement namely GHE, BBHE, DSIHE, RMSHE are discussed. Some basic definitions and notations are also attached. All analysis are done by using MATLAB . Pictures are taken from the book "Digital Image Processing" by Rafael C. Gonzalez and Richard E. Woods. The presentation slide was made for my B.Sc project purpose.
COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...Hemantha Kulathilake
At the end of this lesson, you should be able to;
describe spatial domain of the digital image.
recognize the image enhancement techniques.
describe and apply the concept of intensity transformation.
express histograms and histogram processing.
describe image noise.
characterize the types of Noise.
describe concept of image restoration.
Histogram Processing
Histogram Equalization
Histogram Matching
Local Histogram processing
Using histogram statistics for image enhancement
Uses for Histogram Processing
Histogram Equalization
Histogram Matching
Local Histogram Processing
Basics of Spatial Filtering
Here in the ppt a detailed description of Image Enhancement Techniques is given which includes topics like Basic Gray level Transformations,Histogram Processing.
Enhancement using Arithmetic/Logic Operations.
image averaging and image averaging methods.
Piecewise-Linear Transformation Functions
Histogram equalization is a method in image processing of contrast adjustment using the image's histogram. Histogram equalization can be used to improve the visual appearance of an image. Peaks in the image histogram (indicating commonly used grey levels) are widened, while the valleys are compressed.
Image Enhancement: Introduction to Spatial Filters, Low Pass Filter and High Pass Filters. Here Discussed Image Smoothing and Image Sharping, Gaussian Filters
A Comparative Study of Histogram Equalization Based Image Enhancement Techniq...Shahbaz Alam
Four widely used histogram equalization techniques for image enhancement namely GHE, BBHE, DSIHE, RMSHE are discussed. Some basic definitions and notations are also attached. All analysis are done by using MATLAB . Pictures are taken from the book "Digital Image Processing" by Rafael C. Gonzalez and Richard E. Woods. The presentation slide was made for my B.Sc project purpose.
Image Enhancement in the Spatial Domain.pdfkamaluddinnstu
The principal objective of enhancement is to
process an image so that the result is more
suitable than the original image for a specific
application.
Image enhancement approaches fall into two
broad categories:
- Spatial domain methods
- Frequency domain methods
The term spatial domain refers to the image
plane itself, and approaches in this category are
based on direct manipulation of pixel in an image.
Frequency domain processing techniques are
based on modifying the Fourier transformation of
an image.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
2. Definitions
The principal objective of enhancement is to process an
image so that the result is more suitable for a special
process
Image Enhancement Fall into two categories:
Enhancement in spatial domain and Frequency domain
The term spatial domain refers to the Image Plane itself
which is DIRECT manipulation of pixels.
Frequency domain processing techniques are based on
modifying the Fourier transform of an image.
The principal objective of enhancement is to process an
image so that the result is more suitable for a special
process
Image Enhancement Fall into two categories:
Enhancement in spatial domain and Frequency domain
The term spatial domain refers to the Image Plane itself
which is DIRECT manipulation of pixels.
Frequency domain processing techniques are based on
modifying the Fourier transform of an image.
3. The term “SPATIAL Domain”
Spatial Domain=Aggregate of pixels
composing an image.
Spatial Domain Methods=Procedures that
operate directly on these pixels.
Denoted by: g(x,y)=T[f(x,y)]
F(x,y) : Input Image ,T: Operator on Image
g(x,y): Processed Image.
T also can operate on a set of Images.
Spatial Domain=Aggregate of pixels
composing an image.
Spatial Domain Methods=Procedures that
operate directly on these pixels.
Denoted by: g(x,y)=T[f(x,y)]
F(x,y) : Input Image ,T: Operator on Image
g(x,y): Processed Image.
T also can operate on a set of Images.
4. Definition of Neighborhood:
Input for Process: A neighborhood about a
point (x,y)
The simplest form of input is a one pixel
neighborhood. s=T(r)
T:Transformation Function
s ,r : gray level of f(x,y) and g(x,y) respectively.
The most basic approach is rectangular sub image
area centered at (x,y)
Is it the only solution ???
Input for Process: A neighborhood about a
point (x,y)
The simplest form of input is a one pixel
neighborhood. s=T(r)
T:Transformation Function
s ,r : gray level of f(x,y) and g(x,y) respectively.
The most basic approach is rectangular sub image
area centered at (x,y)
Is it the only solution ???
10. Creating a Transformation In
Matlab/Octave
Step1: Defining the MappingTable
Step2: Use the Mapping table to transfer
pixel values
Step3:Visualization
Step1: Defining the MappingTable
Step2: Use the Mapping table to transfer
pixel values
Step3:Visualization
11. Piece-wise linear transformation
functions
The form of them could be arbitrarily
complex
A practical implementation of some
important transformations can be formulated
only as piece-wise functions.
The form of them could be arbitrarily
complex
A practical implementation of some
important transformations can be formulated
only as piece-wise functions.
12. Contrast Stretching
Is one of the simplest form of piece-wise
linear function.
Low contrast can result from:
Poor Illumination
Lack of dynamic range in the imaging sensor
Wrong setting of lens aperture.
Is one of the simplest form of piece-wise
linear function.
Low contrast can result from:
Poor Illumination
Lack of dynamic range in the imaging sensor
Wrong setting of lens aperture.
15. Linear Transformation cont.
Gray Level Slicing
Highlighting a specific range of gray levels in an
image.
Enhancing features like masses of water in
satellite imageries.
OneApproach: show high values for pixel of
interest.
SecondApproach: Brighten the color of interest
Gray Level Slicing
Highlighting a specific range of gray levels in an
image.
Enhancing features like masses of water in
satellite imageries.
OneApproach: show high values for pixel of
interest.
SecondApproach: Brighten the color of interest
17. Histogram Processing
Histogram is a un normalized PDF for gray
values.
It means that it contains the number of pixels
for each gray value.
So it means there are 3 Histogram for a color
Image, because we have 3 Different Class of
0-255 colors.
Histogram is a un normalized PDF for gray
values.
It means that it contains the number of pixels
for each gray value.
So it means there are 3 Histogram for a color
Image, because we have 3 Different Class of
0-255 colors.
kk nrh )(
20. Histogram Equalization
Histograms could be considered as
Probability Density Functions. So cumulative
density functions could be defined as well.
25. Histogram Matching
The same concept Except we use the CDF of
one image as a non-linearTransform for
another image.
The resulting Image will have more or less the
same Contrast as the reference.
The same concept Except we use the CDF of
one image as a non-linearTransform for
another image.
The resulting Image will have more or less the
same Contrast as the reference.
26. Enhancement Using Arithmetic/Logic
Operations
Performed on a Pixel-by-Pixel basis
Between two or MORE images.
Example: subtraction of two images.
Logic operations=Logic and/or nor xor xnor
Logic operations operate on a pixel-by-pixel
basis.
We only concern about 1-“and” 2-”or” 3-“not”
because they are functionally complete
The other operations could be expresses as a
function of them.
Performed on a Pixel-by-Pixel basis
Between two or MORE images.
Example: subtraction of two images.
Logic operations=Logic and/or nor xor xnor
Logic operations operate on a pixel-by-pixel
basis.
We only concern about 1-“and” 2-”or” 3-“not”
because they are functionally complete
The other operations could be expresses as a
function of them.
30. Spatial Filtering
Input: Neighborhood + Sub-Image
Output:A single value regarding to each pixel
Definition: A neighborhood operation works
with the values of the image pixels in the
neighborhood and values of a sub-image that
has the same dimension….
Sub-Image is called: Mask, Kernel,Template orWindow
Input: Neighborhood + Sub-Image
Output:A single value regarding to each pixel
Definition: A neighborhood operation works
with the values of the image pixels in the
neighborhood and values of a sub-image that
has the same dimension….
Sub-Image is called: Mask, Kernel,Template orWindow
32. Smoothing Filters
N-by-N filters used for noise reduction
Blur an image and remove the high frequency
part of signal
Usually Gaussian Noise could efficiently
remove by them.
Equivalent to High-pass filters in Frequency
domain.
Most-basic type is Mask=ones(3)
N-by-N filters used for noise reduction
Blur an image and remove the high frequency
part of signal
Usually Gaussian Noise could efficiently
remove by them.
Equivalent to High-pass filters in Frequency
domain.
Most-basic type is Mask=ones(3)
34. Order-Statistics Filters
Median
Principal function: to force points with distinct gray
values to be more like their neighbors.
Very suitable for eliminate salt and pepper noise
Max
Min
Mode
They all find an ordering-related elements in a
defined neighborhood and replace it with the
original pixel.
Median
Principal function: to force points with distinct gray
values to be more like their neighbors.
Very suitable for eliminate salt and pepper noise
Max
Min
Mode
They all find an ordering-related elements in a
defined neighborhood and replace it with the
original pixel.
35. Order-statistics Filters Example
Grab a 3x3 Neighborhood
{10,20,20,20,15,20,20,25,100}
Sort them
{10,15,20,20,20,20,25,100}
Calculate order-statistics Filter, example:
Median:20
Grab a 3x3 Neighborhood
{10,20,20,20,15,20,20,25,100}
Sort them
{10,15,20,20,20,20,25,100}
Calculate order-statistics Filter, example:
Median:20
37. Sharpening
Objective: to highlight detail in an image or
enhance detail that has been blurred, either
in error or as a natural effect of a particular
method of image acquisition.
Applications are vary and important from
electronic printing and medical imaging to
industrial inspection and autonomous
guidance in military systems.
Objective: to highlight detail in an image or
enhance detail that has been blurred, either
in error or as a natural effect of a particular
method of image acquisition.
Applications are vary and important from
electronic printing and medical imaging to
industrial inspection and autonomous
guidance in military systems.
38. Sharpening cont.
Image blurring can accomplished in the
spatial domain by pixel averaging in a
neighborhood.
Averaging is analogous to integration
So it is logical to conclude that sharpening
could be accomplished by spatial
differentiation
Image blurring can accomplished in the
spatial domain by pixel averaging in a
neighborhood.
Averaging is analogous to integration
So it is logical to conclude that sharpening
could be accomplished by spatial
differentiation
39. What will be revealed from
image sharpening
Strength of the response of a derivative
operator is proportional to the degree of
discontinuity of the image at that point
So image differentiation will enhances
Edges
Other discontinuities (like Noise)
Deemphasizes
Areas with slowly varying gray-level-values
Strength of the response of a derivative
operator is proportional to the degree of
discontinuity of the image at that point
So image differentiation will enhances
Edges
Other discontinuities (like Noise)
Deemphasizes
Areas with slowly varying gray-level-values
40. Fundamental Properties of
sharpening filters
To simplify we will focus on one dimensional
derivative
We are interested on behavior in
Flat segments
At the onset and end of discontinuities(step,ramp)
Along gray level ramps
To simplify we will focus on one dimensional
derivative
We are interested on behavior in
Flat segments
At the onset and end of discontinuities(step,ramp)
Along gray level ramps
41. First order derivative properties
Any definition for fist order should satisfy:
Must be zero in flat segments
Must be non-zero at the onset of a gray-level step
or ramp
Must be non-zero along ramps
Any definition for fist order should satisfy:
Must be zero in flat segments
Must be non-zero at the onset of a gray-level step
or ramp
Must be non-zero along ramps
42. Second derivative properties
Any definition should satisfy:
Must be zero in flat areas
Must be non-zero at the onset and end of a gray-
level step or ramp
Must be zero along ramps of constant slpe
Any definition should satisfy:
Must be zero in flat areas
Must be non-zero at the onset and end of a gray-
level step or ramp
Must be zero along ramps of constant slpe
43. Basic Definitions
A basic definition of the first order derivative
of a one-dimensional function f(x):
Second order derivative
A basic definition of the first order derivative
of a one-dimensional function f(x):
Second order derivative
45. Derivatives Summary
1st order derivative:
Produces thicker edges in an image
Stronger response to gray level step
2nd order derivative
Stronger response fine details, such as thin lines and
isolated points
Produce double response to step change in gray level
Their responses is greater to a point rather than a line,
to a line rather than a step.
Which one we should choose?
In most applications, the 2nd derivative is better suited
than the 1st for image enhancement
1st order derivative:
Produces thicker edges in an image
Stronger response to gray level step
2nd order derivative
Stronger response fine details, such as thin lines and
isolated points
Produce double response to step change in gray level
Their responses is greater to a point rather than a line,
to a line rather than a step.
Which one we should choose?
In most applications, the 2nd derivative is better suited
than the 1st for image enhancement
46. Isotropic filters
Their response is independent of the
discontinuities in the image to which the filter
applied.
So Isotropic filters are rotation invariant, so
rotating and image and then applying the
filter is same as applying the filter then
rotating the result.
It can be shown(Rosenfeld and Kak [1982])
that the simplest isotropic derivative
operation is Laplacian.
Their response is independent of the
discontinuities in the image to which the filter
applied.
So Isotropic filters are rotation invariant, so
rotating and image and then applying the
filter is same as applying the filter then
rotating the result.
It can be shown(Rosenfeld and Kak [1982])
that the simplest isotropic derivative
operation is Laplacian.
47. Laplacian
Formula
Derivative of any order is linear so Laplacian
is a linear operation
Discrete form of equation
Formula
Derivative of any order is linear so Laplacian
is a linear operation
Discrete form of equation
52. Unsharp Masking
A process used for many years in publishing
industries for image sharpening
Consist of subtracting a blurred version of
image from the image itself.
This process called “unsharp Masking”
A process used for many years in publishing
industries for image sharpening
Consist of subtracting a blurred version of
image from the image itself.
This process called “unsharp Masking”
53. High-Boost Filter
A slight further generalization of unsharp-masking is called high-
boost filtering
Rewrite high-boost equation:
IfA=1 then high-boost is a regular Laplacian.
A slight further generalization of unsharp-masking is called high-
boost filtering
Rewrite high-boost equation:
IfA=1 then high-boost is a regular Laplacian.
56. Background
Discovered by “Jean Baptiste Joseph Fourier”.
Published as aTheory in the book:”Analytic
Theory of Heat” [1822].
55 years later translated in English by
Freeman[1878].
Fourier express that: any function that
periodically repeats itself can be expressed as a
sum of sines/or cosines of different frequencies,
each multiplied by a different coefficient(we call
this sum Fourier series).
Discovered by “Jean Baptiste Joseph Fourier”.
Published as aTheory in the book:”Analytic
Theory of Heat” [1822].
55 years later translated in English by
Freeman[1878].
Fourier express that: any function that
periodically repeats itself can be expressed as a
sum of sines/or cosines of different frequencies,
each multiplied by a different coefficient(we call
this sum Fourier series).
58. One dimensional Fourier
Transform
Direct
Inverse
Components of FourierTransform are
complex numbers (Real and Imaginary Part)
So we have two Images:
Magnitude or Spectrum ofTransform
PhaseAngle or Phase spectrum ofTransform
Direct
Inverse
Components of FourierTransform are
complex numbers (Real and Imaginary Part)
So we have two Images:
Magnitude or Spectrum ofTransform
PhaseAngle or Phase spectrum ofTransform
60. Application of DFT
Filtering: Low-pass and High-pass
Convolution in Spatial Domain is a simple
multiplication in Frequency Domain
So Mask filters are easier in Frequency under
the condition that we have specialized
hardware which can run DFT very fast.
Filtering: Low-pass and High-pass
Convolution in Spatial Domain is a simple
multiplication in Frequency Domain
So Mask filters are easier in Frequency under
the condition that we have specialized
hardware which can run DFT very fast.