Digital image processing operations can be either point or group.
This presentation explains both operations (point and group) and shows how convolution works by a numerical example.
Ahmed Fawzy Gad
ahmed.fawzy@ci.menofia.edu.eg
Information Technology Department
Faculty of Computers and Information (FCI)
Menoufia University
Egypt
Find me on:
AFCIT
http://www.afcit.xyz
YouTube
https://www.youtube.com/channel/UCuewOYbBXH5gwhfOrQOZOdw
Google Plus
https://plus.google.com/u/0/+AhmedGadIT
SlideShare
https://www.slideshare.net/AhmedGadFCIT
LinkedIn
https://www.linkedin.com/in/ahmedfgad/
ResearchGate
https://www.researchgate.net/profile/Ahmed_Gad13
Academia
https://www.academia.edu/
Google Scholar
https://scholar.google.com.eg/citations?user=r07tjocAAAAJ&hl=en
Mendelay
https://www.mendeley.com/profiles/ahmed-gad12/
ORCID
https://orcid.org/0000-0003-1978-8574
StackOverFlow
http://stackoverflow.com/users/5426539/ahmed-gad
Twitter
https://twitter.com/ahmedfgad
Facebook
https://www.facebook.com/ahmed.f.gadd
Pinterest
https://www.pinterest.com/ahmedfgad/
Strategic CX: A Deep Dive into Voice of the Customer Insights for Clarity
Operations in Digital Image Processing + Convolution by Example
1. Operations in Digital Image
Processing + Convolution by Example
MENOUFIA UNIVERSITY
FACULTY OF COMPUTERS AND INFORMATION
ALL DEPARTMENTS
المنوفية جامعة
والمعلومات الحاسبات كلية
جميعاألقسام
المنوفية جامعة
Ahmed Fawzy Gad
ahmed.fawzy@ci.menofia.edu.eg
14. Group Operations – Template Operations
1 Operation 2 Template
Mode
Median
Mean
7x7
5x5
3x3
ODD
Why odd?
15. Group Operations
58 3 213 81 78
185 87 32 27 11
70 66 60 2 19
61 91 129 89 38
14 7 58 14 42Mode
Median
Mean
58 + 3 + 213 + 185 + 87 + 32 + 70 + 66 + 60
9
= 𝟖𝟔
Put the results in the center.
16. Group Operations
58 3 213 81 78
185 87 32 27 11
70 66 60 2 19
61 91 129 89 38
14 7 58 14 42Mode
Median
Mean
58 + 3 + 213 + 185 + 87 + 32 + 70 + 66 + 60
9
= 𝟖𝟔
Put the results in the center.
𝟖𝟔
17. Group Operations – Even Template Size
58 3 213 81 78
185 87 32 27 11
70 66 60 2 19
61 91 129 89 38
14 7 58 14 42Mode
Median
Mean
58 + 3 + 185 + 87
4
= 𝟖𝟑. 𝟐𝟓 ≅ 𝟖𝟒
Even template sizes has no center.
E.g. 2x3, 2x2, 5x6, …
𝟖𝟒
18. Group Operations – Even Template Size
58 3 213 81 78
185 87 32 27 11
70 66 60 2 19
61 91 129 89 38
14 7 58 14 42Mode
Median
Mean
Even template sizes has no center.
E.g. 2x3, 2x2, 5x6, …
𝟖𝟒
???
58 + 3 + 185 + 87
4
= 𝟖𝟑. 𝟐𝟓 ≅ 𝟖𝟒
19. What is Convolution?
• It is a mathematical way to combine two signals to generate a third
signal. Convolution is not limited on digital image processing and it is
a broad term that works on signals.
Input Signal
Impulse Response
Output Signal
System
Convolution
20. What is Convolution?
• It is a mathematical way to combine two signals to generate a third
signal. Convolution is not limited on digital image processing and it is
a broad term that works on signals.
Input Signal
Impulse Response
Output Signal
System
Convolution
58 3 213 81 78
185 87 32 27 11
70 66 60 2 19
61 91 129 89 38
14 7 58 14 42