mengenal pengkodean dan kompresi digital

05/01/23

Author-Tim Dosen

Prodi S1 Teknik Informatika

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CSH1F2 Pengantar Teknik InformatikaPertemuan 4: Mengenal Pengkodean dan Kompresi Digital

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1. Byte dan Ukuran File

Mengenal Pengkodean dan Kompresi Digital

05/01/23

Istilah teknis untuk data 8 bit adalah sebuah Byte.Sebuah byte adalah unit dasar standar (atau “chunk size”) yang mendasari sistem komputer saat ini. “megabyte”, “kilobyte”, “gigabyte”, dan lain lain memiliki jumlah byte berbeda-beda. 8-bit byte telah menjadi unit dasar untuk mengukur “ukuran” data pada komputer

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Byte [1]

CSH1F2 Pengantar Teknik Informatika

05/01/23

in fact, today most computers only let you save data as combinations of whole bytes; even if you only want to store 1 bit of information, you have to use a whole byte to do it. And many computer systems will require you store even more than that. Messages sent over the Internet are also typically structured as messages with byte-offsets.

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Byte [2]


05/01/23

Paralleling the explosion of computing power and speed,the sheer size of the digital data now created and consumed every day is staggering. Units of measure (terabytes) that previously seemed unfathomably large are now making their way into personal computing.This rapid growth of digital data presents many new opportunities and also poses new challenges to engineers and programmers. The implications of so-called Big Data will not be investigated until later in the course, but it’s good and interesting to be thinking about the size of things now.

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Byte [3]


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in addition to the actual text of a document, it is usually necessary to store the formatting information that allows the text to be displayed correctly. We might wonder just how much extra information, i.e. how many extra bytes, we need to store when we include all of this formatting. If a single ASCII character is one byte then if we were to store the word “hello” in a plain ASCII text file in a computer, we would expect it to require 5 bytes (or 40 bits) of memory.

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Ukuran File [1]


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Misal sebuah dokumen Microsoft Word berisi 2 kata “hello world!”?

Perkirakan “Berapa bytes diperlukan sebuah dokumen Word untuk menyimpan 2 kata “hello world!” dibandingkan dengan dokumen teks?

(Demokan details/ properties file text hello.txt dan hello.docx)

Perbedaan ukuran file .txt and .docx disebabkan oleh informasi format yang disertakan bersama teks dalam docx.

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Ukuran File [2]


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1. Byte dan Ukuran File2. Kompresi Teks


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Heuristic - a problem solving approach (algorithm) to find a satisfactory solution where finding an optimal or exact solution is impractical or impossible.Video Aloe Blacc

Lossless Compression - a data compression algorithm that allows the original data to be perfectly reconstructed from the compressed data.

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Kompresi Teks


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Coba kodekan kalimat di lembar kerja

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Aktivitas 1


Sejarah komputer terus mengalami perkembangan dari generasi ke generasi. Kami akan membahas sejarah itu secara singkat namun lengkap disini. Dari pertama kali dibuat, komputer telah mengalami perubahan dan perkembangan yang sangat pesat. Kini komputer bukan sekadar untuk olah kata dan data, komputer telah menjadi barang yang "serba bisa". Kita bermain game, mendengar musik, membuat animasi dan film, menyelesaikan tugas-tugas sekolah dan lain-lain, semuanya dapat diselesaikan dengan komputer. Sistem komputer di kassa dapat membaca kode barang, di perkantoran, jaringan komputer dan internet yang menghubungkan berbagai tempat di dunia, semuanya menggunakan komputer.

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Aktivitas 1 (lanjutan)Hitung jumlah karakter dalam paragrap diatasBuat kode untuk tiap kata yang ada, satu kata dapat menggunakan satu atau lebih karakter kodeGanti tiap kata dengan kode yang anda buat.Hitung berapa karakter dokumen anda sekarangBerapa persen dokumen pengurangan karakter dalam dokumen tersebut?

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1. Byte dan Ukuran File2. Kompresi Teks3. Pengkodean gambar hitam putih


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Image - A type of data used for graphics or pictures.metadata - is data that describes other data. For example, a digital image my include metadata that describe the size of the image, number of colors, or resolution.pixel - short for "picture element" it is the fundamental unit of a digital image, typically a tiny square or dot which contains a single point of color of a larger image.Color depth: the number of bits devoted to each pixelRGB - the RGB color model uses varying intensities of (R)ed, (G)reen, and (B)lue light are added together in to reproduce a broad array of colors.

Vocabulary


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Drawing software stores a picture as a collection of lines and shapes (called object-oriented or vector graphics).Video: A little bit about pixel

Vocabulary


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Tipe file gambar serupa dengan paket data di InternetKarena gambar harus mencakup metadata, atau data tentang data. Data gambar hitam putih merupakan sederet bit yang menyatakan apakah setiap pixel on atau off.Untuk membuat gambar/ image, kita perlu tahu panjang dan lebar image agar bisa dibuat ulang secara akurat.

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Pengkodean Gambar hitam putih


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Digital images can be stored in many formats, but one of the most common formats is “raster”. Raster images store the image as an array of individual pixels, each of which has a particular color. Higher-quality images can be obtained by decreasing the size of the pixels (resolution). images on computer screens are created with light by illuminating pixels on the screen.

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Pengkodean Gambar hitam putih


05/01/23

The most common color representation scheme - RGB - typically uses 24 bits (3 bytes) with 8 bits each for Red, Green and Blue intensities. And one of the most common ways you see these colors represented is in hexadecimal. The process of rendering color on a computer screen: mixing red, green and blue light

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Pengkodean Gambar berwarna


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Mengapa file gambar perlu dikompresi?Perhatikan bahwa uncompressed image file ukurannya bisa cukup besarSebagai contoh, bahkan sebuah gambar yang relatif kecil berukuran 250x250 pixels = 62,500 pixels, masing-masing pixel membutuhkan sampai tiga bytes (24 bits) atau informasi warna, sehingga totalnya tersimpan 1.5 juta bit untuk satu image tersebut!

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Pengkodean Gambar berwarna


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1. Jelaskan mengenai 2 jenis image, yaitu raster dan vector! (Definisi, type file dan Software, dan karakteristiknya)!

2. Jelaskan mengenai kompresi file gambar, jelaskan secara rinci 2 diantaranya!

3. Jelaskan mengenai color depth atau bit depth dalam file gambar!

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Worksheet

05/01/23

THANK YOU

mengenal pengkodean dan kompresi digital

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