Pengantar Pengolahan Citra Digital (KOM 421) – 3(2-3)
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Pengantar Pengolahan Citra Digital (KOM 421) – 3(2-3) Kuliah 01: Pendahuluan Yeni Herdiyeni Departemen Ilmu Komputer IPB Semester Ganjil 2008
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Topik
- Tujuan Instruksional Umum: Mahasiswa mampu menjelaskan, mengolah dan menganalisis citra digital.
- Deskripsi: Mata kuliah ini menjelaskan karakteristik citra digital, analisis dan pengolahan citra digital seperti image formation, image restoration, image enhancement, transformasi citra dalam ruang frekuensi, kompresi citra, deteksi tepi, segmentasi citra, morfologi citra dan pengenalan pola. Perangkat lunak yang digunakan MATLAB dan C
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Buku Bacaan:
- Gonzalez, R. C., Woods, R. E., Eddins, Steven. 2004. Digital Image
Processing Using Matlab. Prentice Hall. (BUKU UTAMA)
- Alasdair McAndrew. 2004. Introduction to Digital Image Processing with Matlab. Thomson Course Technology, USA.
- Acharya, Tinku dan Ray, A.K. 2005. Image Processing. Principles and
Applications. A John Wiley and Sons, Inc., Publication
- Russ, John. C. 2007. The Image Processing Handbook, Fifth Edition. Taylor & Francis Group, LLC
- Umbaugh, S.C. 1999. Computer Vision and Image Processing. A Practical Approach using CVI Tools. Prentice Hall PTR.
- Rastislav Lukac dan Konstantinos. 2007. Color Image Processing. Methods
and Applications. Taylor & Francis Group, LLC
- Pitas, I. Digital Image Processing Algorithm. 1993. Prentice Hall • Bahan bacaan lain yang relevan
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Pengajar
- Yeni Herdiyeni • Aziz Kustiyo • Sony Hartono (Praktikum)
Komponen Penilaian
- UTS
- UAS
- Tugas • Quiz • Project
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Materi Kuliah
- Pertemuan 1 : Pendahuluan • Pertemuan 2 : Citra Digital dan Matlab • Pertemuan 3 : Pengolahan Titik • Pertemuan 4 : Restorasi Citra • Pertemuan 5 : Image Enhancement • Pertemuan 6 : Pengolahan Warna • Pertemuan 7 : Transformasi Citra pada ruang frekuensi (Fourier Transformation)
- Ujian Tengah Semester
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Materi Kuliah #2
- Pertemuan 8 : Transformasi Citra pada ruang frekuensi (Wavelet Transformation)
- Pertemuan 9 : Deteksi tepi (edge detection)
- Pertemuan 10 : Segmentasi Citra • Pertemuan 11 : Morfologi Citra • Pertemuan 12 : Pemampatan Citra (Image Compression
- – RLE, Huffman Code)
- Pertemuan 14 : Pengenalan Pola (Pattern Recognition)
- Ujian Akhir Semester
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital DIP astronomy seismology inspection autonomous navigation reconnassaince & mapping remote sensing surveillance microscopy radiology robotic assembly digital library ultrasonic imaging radar, SAR meteorology internet Applications of Digital Image Processing (DIP)
From Prof. Alan C. Bovik Departemen Ilmu Komputer -IPB
Pengantar Pengolahan Citra Digital Image Formation
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
9 1999-2007 by Richard Alan Peters II
Image Formation Departemen Ilmu Komputer -IPB
27 August 2008
Pengantar Pengolahan Citra Digital Image Formation projection through lens image of object
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Image Formation projection onto discrete sensor digital camera array.
1999-2007 by Richard Alan
27 August 2008
11 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Image Formation sensors register average color. sampled image
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Image Formation continuous colors, discrete locations. discrete real- valued image
1999-2007 by Richard Alan
27 August 2008
13 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Digital Image Formation: Quantization t u tp u r o o continuous colors col mapped to a finite, te e discrete set of colors. cr is d continuous color input
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Sampling and Quantization pixel grid real image sampled quantized sampled & quantized
1999-2007 by Richard Alan
27 August 2008
15 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Color images have 3 values per pixel; monochrome images have 1
Digital Image value per pixel. a grid of squares, each of which contains a single color each square is called a pixel (for picture element)
Pengolahan Titik Departemen Ilmu Komputer -IPB
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
- gamma original + gamma + brightness - brightness
- contrast original + contrast histogram EQ histogram mod
Pengantar Pengolahan Citra Digital original blurred sharpened
Spatial Filtering
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Spatial Filtering bandpass original unsharp filter masking
1999-2007 by Richard Alan
27 August 2008
19 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Spatial Filtering signed image with 0 at middle gray bandpass original unsharp filter masking
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
21 1999-2007 by Richard Alan Peters II
Motion Blur vertical regional zoom rotational original
27 August 2008
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital color noise blurred image color-only blur
Noise Reduction
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
23 1999-2007 by Richard Alan Peters II
5x5 Wiener filter color noise blurred image Noise Reduction
27 August 2008
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
Noise Reduction original periodic noise frequency tuned filter
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Color Images
- Are constructed from three intensity maps.
- Each intensity map is pro-jected through a color filter (e.g., red, green, or blue, or cyan, magenta, or yellow) to create a monochrome image.
- The intensity maps are overlaid to create a color image.
- Each pixel in a color image is a three element vector.
27 August 2008 1999-2007 by Richard Alan Peters II
25 Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Color Image s On a CRT
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Color Processing requires some knowledge of how we see colors
1999-2007 by Richard Alan
27 August 2008
27 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Eye’s Light Sensors cone density near fovea
#(blue) << #(red) < #(green)
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Color Sensing / Color Perception
These are approximations of the responses to the visible spectrum of the “red”, “green”, and “blue” receptors of a typical human eye.
1999-2007 by Richard Alan
27 August 2008
29 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Color Sensing / Color Perception
These are approximations of the responses to the visible spectrum of the “red”, “green”, and “blue” receptors of a typical human eye.
The simultaneous red + blue response causes us to perceive a continuous range of hues on a circle. No hue is greater than or less than any other hue.
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Color Sensing / Color Perception lu m
The eye has 3 types of photoreceptors: in a sensitive to red, green, or blue light. n ce hue sa tu ra tio The brain transforms RGB into separate n
brightness and color channels (e.g., LHS).
brain photo receptors1999-2007 by Richard Alan
27 August 2008
31 Peters II luminance and chrominance
Color Perception Pengantar Pengolahan Citra Digital
(hue+saturation) are perceived Departemen Ilmu Komputer -IPB pixelization of:
16 with different resolutions, as × are red, green and blue. luminance chrominance all bands green blue red Color Perception Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB pixelization of:
16 × luminance chrominance all bands green blue red
1999-2007 by Richard Alan
27 August 2008
33 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Color Balance and Saturation
Uniform changes in color components result in change of tint.
E.g., if all G pixel values are multiplied by > 1 then the image takes a green cast.
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
Pengantar Pengolahan Citra Digital The 2D Fourier Transform of a Digital Image
Image aging: a transformation, , that mapped: Departemen Ilmu Komputer -IPB
106 227 236
166 230 240
1
103 171 240
160 171 240
2
1
185 222 222
1
2D sinusoids.
I Let I(r,c) be a single-band (intensity) digital image with R rows and C columns. Then, I(r,c) has Fourier representation where are the R x C Fourier coefficients. these complex exponentials are
R C RC r c u,v I r c e
1 ( , ) ur vc R C i
2
1
, , , ur vc R i C
I
R C u v I r c u v e
218 222 222
35 1999-2007 by Richard Alan Peters II
103 171 240
106 227 236
17
114 122
185 222 222
218 222 222
Color Transformations
160 171 240
17
17 114 122
171 121
166 230 240
17
171 121
27 August 2008
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
A 2 c r
I r , c cos cos sin
1
2D Sinusoids: 2 C R
c
... are plane waves with grayscale amplitudes, periods in terms of lengths, ...
r orientation
A = phase shift
1999-2007 by Richard Alan
27 August 2008
37 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB ... specific orientations,
2D Sinusoids: and phase shifts. c c r r
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
39 1999-2007 by Richard Alan Peters II
The Value of a Fourier Coefficient … … is a complex number with a real part and an imaginary part.
If you represent that number as a magnitude, A, and a phase, , …
..these represent the amplitude
and offset of the sinusoid with
frequency w and direction .
27 August 2008
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
The Sinusoid from the Fourier Coeff. at (u,v)
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
The Fourier Transform of an Image magnitude phase
|F{I}| [F{I}]
I 1999-2007 by Richard Alan
27 August 2008
41 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Continuous Fourier Transform
i 2 ( uc vr )
I I r , c u , v e dudv
i 2 ( uc vr )
I
u , v I r , c e dcdr
The continuous Fourier transform assumes a continuous image exists in a finite region of an infinite plane.
The BoingBoing Bloggers
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
I The BoingBoing Bloggers Departemen Ilmu Komputer -IPB
Discrete Fourier Transform The discrete Fourier transform assumes a digital image exists on a closed surface, a torus.
1 2 1
) (
I C u R vr C uc R i v e u,v r,c
I
1 2 1
, I , C c R rv C cu i R r e c r v u
27 August 2008
Pengantar Pengolahan Citra Digital Convolution
16 , 16
Sum times 1/5 Sums of shifted and weighted copies of images or Fourier transforms.
c r
16 , 16
c r
c r
16 , 16
, c r
c r
43 1999-2007 by Richard Alan Peters II
16 , 16
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Convolution Property of the Fourier Transform f r c g r c
Let functions ( , ) and ( , ) have The Fourier Transform of a Fourier Transforms F ( u , v ) and G ( u , v ). product equals the convolution of Then, the Fourier Transforms. Similarly, the Fourier Transform of a
F f g F G { } . convolution is the product of the M oreover,
Fourier Transforms
F f g F G { } .
represents convolutio n represents pointwise multiplica tion Then, a spatial convolutio n can be computed by
1 F
- - f g F G .
1999-2007 by Richard Alan
27 August 2008
45 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Boundary Detection
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Boundary Detection Finding the Corpus Callosum (G. Hamarneh, T. McInerney, D. Terzopoulos)
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Nonlinear Processing: Binary Morphology
Cross-hatched
“L” shaped SE Foreground: white pixels
pixels are indeterminate.
O marks origin Background: black pixels
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Image Compression Original image is 5244w x 4716h @ 1200 ppi: 127MBytes
Yoyogi Park, Tokyo, October 1999. Photo by Alan Peters.
1999-2007 by Richard Alan
27 August 2008
49 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Image Compression: JPEG
Fi vel le le si ze ity al in b u q y
G tes
E JP
Pengantar Pengolahan Citra Digital Departemen Ilmu Komputer -IPB
Image Compression: JPEG Fi vel le le si ze ity al in b u q y
G tes
E JP 1999-2007 by Richard Alan
27 August 2008
51 Peters II Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Recognition - Shading
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
Departemen Ilmu Komputer -IPB Pengantar Pengolahan Citra Digital
Classification (Funkhauser, Min, Kazhdan, Chen, Halderman, Dobkin, Jacobs)