2 pengolahan_citra
DESCRIPTION
TRANSCRIPT
![Page 1: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/1.jpg)
#2 Pengolahan Citra
Hari Wibawanto
![Page 2: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/2.jpg)
(a) Kamera digital (b) Kamera CCTV
(c) Pemindai (Scanner) (d) Pembaca Sidik Jari
Perangkat penangkap/ penghasil citra (1)
![Page 3: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/3.jpg)
Magnetic Resonance Imaging
![Page 4: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/4.jpg)
CT Scan
![Page 5: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/5.jpg)
Ground Penetrating Radar
![Page 6: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/6.jpg)
Ultrasonography
![Page 7: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/7.jpg)
X-Ray Photo
![Page 8: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/8.jpg)
Apa itu Pengolahan Citra Digital?
• “pemrosesan gambar berdimensi-dua melalui komputer digital” (Jain, 1989)
• pengolahan citra adalah berbagai teknik untuk memanipulasi dan memodifikasi citra dengan berbagai cara(Efford, 2000)
![Page 9: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/9.jpg)
Aplikasi Pengolahan Citra
• pengenalan pola (identifikasi sidik jari, iris, retina, pengenalan wajah)
• penginderaan jarak-jauh melalui satelit atau pesawat udara,
• machine vision• mesin penginspeksi
![Page 10: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/10.jpg)
Efek gambar dengan teknik pengolahan citra
![Page 11: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/11.jpg)
Prinsip dasar: mengubah kontras
![Page 12: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/12.jpg)
Penghilangan derau
![Page 13: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/13.jpg)
Ekstraksi bentuk obyek
![Page 14: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/14.jpg)
Representasi Citra Digital
• Citra digital dibentuk oleh kumpulan titik yang dinamakan piksel (pixel atau “picture element”)
• Setiap piksel digambarkan sebagai satu kotak kecil
• Setiap piksel mempunyai koordinat posisi
![Page 15: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/15.jpg)
Sistem koordinat citra berukuran M x N
![Page 16: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/16.jpg)
Citra dan nilai penyusun piksel
![Page 17: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/17.jpg)
Notasi piksel dalam citra
![Page 18: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/18.jpg)
Kuantisasi: mengubah analog menjadi digital
![Page 19: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/19.jpg)
Digitalisasi citra biner 8x8 piksel
![Page 20: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/20.jpg)
Bit per Piksel
Jangkauan Penggunaan
1 0-1 Citra biner: dokumen faksimili
8 0-255 Umum: foto dan hasil pemindai
12 0-4095 Kualitas tinggi: foto/hasil pemindai
14 0-16383 Kualitas prof: foto/hasil pemindai
16 0-65535 Kualitas tertinggi: citra kedokteran dan astronomi
![Page 21: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/21.jpg)
Kuantisasi citra dengan menggunakan berbagai bit
![Page 22: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/22.jpg)
Kualitas Citra: jumlah piksel
![Page 23: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/23.jpg)
Membaca citra dengan Matlab atau OctaveImg = imread(nama_file_citra)
Format Ekstensi Keterangan
TIFF .tif, .tiff Tagged Image File Format
JPEG .jpg, .jpeg Joint Photographics Expert Group
GIF .gif Graphics Interface Format
BMP .bmp Windows Bitmap
PNG .png Portable Network Graphics
XWD .xwd XWindow Dump
Img = imread(’C:\Image\mandrill.png’);
![Page 24: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/24.jpg)
Perintah lain
>> Ukuran = size(Img); >> jum_baris = Ukuran(1); >> jum_kolom = Ukuran(2); atau>> [jum_baris, jum_kolom] = size(Img); >> imshow(Img);
![Page 25: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/25.jpg)
untuk menampilkan dua citra di dua jendela masing-masing, fungsi figure perlu dipanggil terlebih dulu sebelum memanggil imshow
>> Sungai = imread('C:\Image\innsbruck.png'); >> Bangunan = imread('C:\Image\altstadt.png'); >> figure(1); imshow(Sungai); >> figure(2); imshow(Bangunan);
![Page 26: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/26.jpg)
Dua citra di dua jendela
![Page 27: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/27.jpg)
Dua citra dalam satu jendela
>> close all; >> subplot(1,2,1); imshow(Sungai); >> subplot(1,2,2); imshow(Bangunan);
Contoh perintahnya:
![Page 28: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/28.jpg)
Dua citra dalam satu jendela
![Page 29: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/29.jpg)
Warna RGB dalam ruang berdimensi tiga
![Page 30: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/30.jpg)
Citra berwarna dan representasinya
![Page 31: 2 pengolahan_citra](https://reader036.vdocuments.mx/reader036/viewer/2022062616/54b4da004a79593d368b4730/html5/thumbnails/31.jpg)
Mengubah citra menjadi citra biner% KEBINER Digunakan untuk mengonversi file % daun_gray.png ke citra biner Img = imread('c:\Image\daun_gray.png');[tinggi, lebar] = size(Img); ambang = 210; % Nilai ini bisa diubah-ubahbiner = zeros(tinggi, lebar);for baris=1 : tinggi for kolom=1 : lebar if Img(baris, kolom) >= ambang Biner(baris, kolom) = 0; else Biner(baris, kolom) = 1; end endend imshow(Biner);