Pengertian Vector dan Bitmap
Berikut penjelasan mengenai vector dan bitmap dalam desain grafis yang harus Anda ketahui sebelum membuat desain sebuah projek. Bagi orang awam melihat sebuah gambar itu sama saja, namun di dunia design grafis gambar dibagi menjadi 2 jenis tergantung dari tipe gambar dan model gambar. Jika Anda sudah biasa dalam dunia Graphic Design nama vector dan bitmap sudah tidak asing yang biasa digunakan untuk membedakan sebuah gambar.
Vector dan bitmap memiliki fungsi, kelebihan, dan kekurangan masing-masing tergantung kebutuhan dari sebuah design grafis. Oleh karena itu, kita akan berbagi sedikit pengertian vector dan bitmap mulai dari fungsi, kelebihan, dan kekurangan serta perbedaannya.
Pengertian Vector dan Bitmap
Pengertian Vector
Vector adalah gambar yang terbuat dari beberapa titik dan garis (poligon), kombinasi gambar jenis ini melalui proses rumus matematika khusus dalam pembuatan gambar. Setiap alur vector dapat dengan mudah ditambah atribut untuk membuat berbagai bentuk yang diinginkan. Vector juga dapat ditambahkan dan menghilangkan atribut seperti ketebalan garis, warna, warna isi, nodes dan lainnya.
Pengertian Bitmap
Bitmap adalah terbentuknya dari banyak titik dengan campuran warna di dalam grafis yang ada pada komputer. Gambar ini merupakan hasil dari susunan warna yang mewakili dari beberapa pixel warna dan tampil pada layar monitor. Pada umumnya jenis gambar bitmap, memiliki gambar yang tinggi dan lebar dalam bentuk pixel dengan jumlah bit. Ada beberapa format gambar yang sering kita temui dan tergolong dalam jenis bitmap seperti JPEG, BMP, PNG, dan GIF.
Kelebihan dan Kekurangan Vector
Kelebihan Grafis Vector
1. Gambar jenis objek vector bisa diubah dalam bentuk dan ukuran tanpa harus menurunkan kualitas grafis.
2. Proses membuat gambar dan edit gambar terbilang sangat mudah, maka akan terasa menyenangkan.
3. Hasil grafis vector bisa di print dengan kualitas terbaik dari printer.
4. Kapasitas penyimpanan objek gambar vector lebih efisien.
Kekurangan Grafis Vector
1. Saat ingin mengkonversikan objek gambar vector ke format gambar bitmap, hasilnya tidak bisa menampilkan vector utama.
2. Grafis vector tidak dapat menampilkan suatu gambar dan gradasi secara realistis atau senatural gambar umumnya.
Kelebihan dan Kekurangan Bitmap
Kelebihan Grafis Bitmap
1. Bisa memberi hasil objek gambar bitmap ke objek gambar vector dengan sangat cepat dan mudah, sementara kualitas gambar bisa kita tentukan.
2. Pemberian efek khusus bisa dilakukan dengan mudah, sehingga setiap orang bisa membuat objek tampilan yang sesuai keinginan.
3. Objek gambar bitmap bisa menangkap warna dan bentuk secara alami.
Kekurangan Grafis Bitmap
1. Ketika memberi efek pada objek gambar bitmap dan mencetaknya, gambar akan menjadi pecah serta detailnya akan berkurang jika mencetaknya dengan resolusi yang lebih rendah.
2. Objek gambar bitmap sangat bermasalah saat diubah ukuran, terutama saat gambar diperbesar dan gambar akan menjadi pecah.
Perbedaan Vector dan Bitmap
Ketika kita berbicara pengertian vector dan bitmap, maka kita harus tahu perbedaan apa saja dari ke 2 grafis tersebut.
1. Vector: terbentuk dari karya dan garis, ukuran file penyimpanan kecil, detail gambar tetap saat diperbesar dan kualitas tidak bergantung pada banyak pixel.
2. Bitmap: terbentuk dari titik atau dot, ukuran file penyimpanan besar, detail gambar menjadi tidak jelas saat diperbesar, dan kualitas bergantung pada banyak pixel.
Aplikasi Pembuat Vector dan Bitmap
Sudah banyak aplikasi yang bisa digunakan untuk membuat grafis vector dan bitmap seperti Corel Photo Paint, PT Maker, Adobe Photoshop, CorelDraw, dan masih banyak lainnya. Namun aplikasi yang banyak digunakan adalah Adobe Photoshop dan Corel Draw yang memiliki manajemen warna yang lebih lengkap. Demikian pengertian vector dan bitmap yang harus diketahui dalam desain grafis meski secara garis besar keduanya tidak jauh berbeda namun memiliki fungsi, kelebihan dan kekurangan yang berbeda.
Saat menjelaskan gambar bitmap, pikirkan Lite Brite. Anda yang cukup dimanjakan saat anak-anak bermain dengan mainan ini ingat bahwa Anda memasang pasak kecil berwarna ke dalam kotak dan kemudian membalik sakelar untuk menyalakannya.
Bitmap bekerja dengan cara yang hampir sama. Dalam istilah sederhana, grafik bitmap adalah kisi yang diisi dengan piksel berwarna kecil. Untuk menggambar grafik bitmap di layar, komputer menjabarkan sebuah kisi, katakan 100 x 100 piksel, dan kemudian memetakan warna ke setiap piksel individu. Itu 10.000 piksel untuk menggambar! Ingat, sebuah piksel berukuran 1/72 inci. Oleh karena itu, jika sebuah gambar memiliki resolusi 72 dpi dan lebar 100 piksel, maka akan muncul lebih dari satu inci lebar di layar komputer. Gambar berikut adalah tipikal dari bitmap.
Gambar vektor di Internet
Jika Anda tidak ingat Lite Brite, maka Anda tentu ingat "Hubungkan Dots." Grafik vektor menggunakan strategi yang sama. Rumus matematika menempatkan titik-titik pada layar dan kemudian menghubungkannya dengan jalur. Misalnya, untuk menggambar grafik vektor berbentuk segitiga di layar, komputer cukup meletakkan tiga titik, menghubungkannya, dan mengisinya dengan warna. Dalam contoh kedua, Anda dapat melihat beberapa poin - beberapa dengan pegangan keluar dari mereka. Gagang ini mengontrol kurva jalur antara dua titik - dikenal sebagai kurva Bézier bagi yang tahu. Gambar berikut akan berfungsi dengan baik sebagai vektor.
Jika Anda berpikir bahwa vektor dapat menggambar grafik di layar jauh lebih efisien daripada bitmap, Anda benar. Grafik vektor memiliki ukuran file yang sangat kecil, membuatnya ideal untuk pengiriman online. Namun, kedua grafik vektor dan bitmap memiliki pro dan kontra.
Vector vs. Bitmap Images
What are vector and bitmap images, and how are they different?
Vector
· Made of shapes.
· More scalable without losing quality.
· More specialized uses.
Bitmap
· Made of pixels.
· Compatible with Microsoft Paint, Adobe Photoshop, Corel Photo-Paint, Corel Paint Shop Pro, and GIMP.
· Lose quality when the image is resized larger.
Vector and bitmap images are both pictures on a screen, but they have different compositions and focuses. Bitmaps are made of pixels, while vector images are software-created and based on mathematical calculations.
Bitmaps are not only more common in everyday life but are easier to use. You can quickly convert one format of bitmap image into another, and you can't turn a bitmap into a vector without special software.
Vector images are generally smoother and more usable, and you can scale them freely without sacrificing quality. In general, vectors are for making scalable work files, while bitmaps are for making sharable final products.
Formats: Bitmaps Are More Ubiquitous
Vector
· Includes AI, CDR, CMX (Corel Metafile Exchange Image), SVG, CGM (Computer Graphics Metafile), DXF, and WMF (Windows Metafile).
Bitmap
· Includes GIF, JPG, PNG, TIFF, and PSD.
Vectors are more specialized files and tend to appear in less common formats. Every picture you see on your phone, tablet, or computer is a bitmap, even if someone created it using vector tools.
Bitmap images (also known as raster images) are made up of pixels in a grid. Pixels are picture elements, tiny squares of individual color that make up what you see on the screen. All these squares of color come together to form the images you see.
Although not as commonly used as bitmap graphics, vector graphics have a lot of virtues. Vector images are made up of many individuals, scalable objects. They always render at the highest quality because they are device-independent. Objects in a vector image might consist of lines, curves, and shapes with editable attributes such as color, fill, and outline.
Ease of Use: Vectors Are More Robust
Vector
· Resolution-independent.
· Maximum quality regardless of scale.
Bitmap
· Lose quality when scaling.
· Easier to go from vector to bitmap than the other way.
Because bitmaps are resolution-dependent, it's impossible to increase or decrease their size without sacrificing image quality. When you reduce the size of a bitmap image through your software's resample or resize option, pixels must be discarded.
When you increase the size of a bitmap image, the software creates new pixels. When creating pixels, the software has to estimate the color values of the new pixels based on the surrounding pixels. This process is called interpolation.
If a red pixel and a blue pixel are beside each other and you double the resolution, two pixels will be added between them. Interpolation determines which color those added pixels will be; the computer adds what it thinks are the correct colors.
Scaling an image does not affect the image permanently. In other words, it doesn't change the number of pixels in the image. What it does is make them bigger. However, if you scale a bitmap image to a larger size in your page layout software, you'll see a definite jagged appearance. Even if you don't see it on your screen, it will be apparent in the printed image.
Scaling a bitmap image to a smaller size doesn't have any effect. When you do this, you increase the PPI of the image so that it prints clearer. This happens because it has the same number of pixels but in a smaller area.
Vector objects are defined by mathematical equations, called Bezier Curves, rather than pixels. Changing the attributes of a vector object does not affect the object itself. You can freely change any number of object attributes without destroying the basic object. An object can be modified by changing its attributes and by shaping and transforming it using nodes and control handles.
Fonts are one type of vector object. You can see an example of the data behind a vector image in this explanation of an SVG file.
Because they're scalable, vector-based images are resolution-independent. You can increase and decrease the size of vector images to any degree, and the lines will remain crisp and sharp, both on-screen and in print.
When you convert a vector image to a bitmap, you can specify the output resolution of the final bitmap for whatever size you need. It's important to save a copy of the original vector artwork in its native format before converting it to a bitmap. Once it has been converted to a bitmap, the image loses all the qualities it had in its vector state.
The most common reason to convert a vector to a bitmap would be for use on the web. The most common and accepted format for vector images on the web is Scalable Vector Graphics (SVG).
Due to the nature of vector images, they're best converted to GIF or PNG format for use on the web. This is slowly changing because many modern browsers are able to render SVG images.
The Final Product: Cartoons vs. Photos
Vector
· Made of solid blocks of color.
· Can be any shape.
Bitmap
· Captures greater detail due to high pixel counts.
· Restricted to a square or rectangle shape.
Vector graphics are continually becoming more advanced. Today's vector tools apply bitmapped textures to objects, giving them a photo-realistic appearance. These tools also create soft blends, transparency, and shading that once was difficult to achieve in vector drawing programs.
Another advantage of vector images is that they're not restricted to a rectangular shape like bitmaps. Vector objects can be placed over other objects, and the object below will show through. A vector circle and bitmap circle appear to be the same when seen on a white background. However, when a bitmap circle is placed over another color, it has a rectangular box around it from the white pixels in the image.
Final Verdict
Vector images have many advantages, but the primary disadvantage is that they're unsuitable for producing photo-realistic imagery. Vector images usually consist of solid areas of color or gradients, but cannot depict the continuous subtle tones of a photograph. That's why most vector images tend to have a cartoon-like appearance.
Vector images primarily originate from the software. You can't scan an image and save it as a vector file without using special conversion software. On the other hand, vector images can easily be converted to bitmaps. This process is called rasterizing.
Bitmap versus vector graphics
Digital images can usually be divided into two distinct categories. They are either bitmap files or vector graphics. If you work in prepress, you need a good understanding of the advantages and disadvantages of both types of data. These pages try to explain the differences.
· As a general rule, digital pictures and scanned images are bitmap files. These are sometimes also called raster images.
· Drawings made in applications like Adobe Illustrator or Corel Draw are saved as vector graphics.
Technically both data formats are completely different. The end result, however, can look virtually identical in either format. As a general rule bitmaps are typically used to depict lifelike images whereas vector graphics are more often used for abstract images such as logos. There are however numerous exceptions to this rule. It is often impossible to determine whether an image is a bitmap or a vector file just by looking at it.
· Vexel art, for instance, are bitmap images that have been manipulated to look as if they are vector data. The technique is used to create attention-grabbing realistic images that have an artificial and sharpened look to them.
· Talented artists like Yukio Miyamoto can draw photorealistic images using vectors.
Photorealistic vector art from Yukio Miyamoto
You can convert a bitmap image into a vector file. A vector image can be transformed into a bitmap. There are even file formats that can combine both types of data into a single file.
Bitmap images
Bitmap images are exactly what their name says they are: a collection of bits that form an image. The image consists of a matrix of individual dots (or pixels) that all have their own color (described using bits, the smallest possible units of information for a computer).
Let’s take a look at a typical bitmap image to demonstrate the principle:
Example of a bitmap image
To the left you see an image and to the right a 250 percent enlargement of the top of one of the mountains. As you can see the image consists of hundreds of rows and columns of small elements that all have their own color. One such element is called a pixel – short for picture element. The human eye is not capable of seeing each individual pixel so we perceive a picture with smooth gradations.
The number of pixels you need to get a realistic looking image depends on the way the image will be used. One of the next pages goes into more detail on this.
Types of bitmap images
Bitmap images can contain any number of colors but there are four main categories:
1. Line-art. These are images that only contain two colors, usually black and white. Sometimes these images are referred to as bitmaps because a computer has to use only 1 bit (on=black, off=white) to define each pixel.
Example of a lineart image
2. Grayscale images, which contain various shades of gray as well as pure black and white.Typically 256 shades of gray (8-bit) are used even though the human visual system needs only 100 tints to perceive an image as life-like.
Example of a grayscale image
3. Multitones: such images contain shades of two or more colors. The most popular multitone images are duotones, which usually consist of black and a second spot color (often a Pantone color). The example below contains black and Pantone Warm Red.
Example of a duotone image
4. Full-color images. The color information can be described using a number of color spaces: RGB, CMYK or Lab for instance.
Example of a color image
Characteristics of bitmap data
Bitmap data can take up a lot of room. A CMYK A4-size picture that is optimized for medium quality printing (150 lpi) takes up 40 MB. Compression can reduce the size of the file.
The image with the enlargement showed one of the main disadvantages of bitmap images: once they are enlarged too much, they look unnatural and blocky. Reducing their sizes also has an impact on image quality as images lose a bit of sharpness.
Bitmaps are fairly simple to output, as long as your RIP or printer has sufficient memory.
Applications that can handle bitmap data
There are hundreds of applications on the market that can be used to create or modify bitmap data. In prepress, one application – Adobe Photoshop – completely dominates the market. This doesn’t mean that cheaper alternatives like Corel Photo-Paint, should be disregarded.
File formats that are used for bitmap data
Bitmap data can be saved in a wide variety of file formats. Among these are:
· BMP: an outdated and limited file format that is not suitable for use in prepress.
· EPS: a flexible file format that can contain both bitmap and vector data. It is gradually being replaced by PDF.
· GIF: mainly used for internet graphics
· JPEG: or rather the JFIF file format, which is mainly used for internet graphics
· PDF: versatile file format that can contain just about any type of data including complete pages, it is not yet widely used to exchange just images
· PICT: a file format that can contain both bitmap and vector data but that is mainly used on Macintosh computers and is not very suitable for prepress.
· PSD: the native file format of Adobe Photoshop (which can also contain vector data such as clipping paths)
· TIFF: a popular and versatile bitmap file format
Vector graphics
Vector graphics are images that are completely described using mathematical definitions. The image below shows the principle. To the left, you see the image itself and to the right, you see the actual lines that make up the drawing.
Example of a vector image
Each individual line is made up of either a vast collection of points with lines interconnecting all of them or just a few control points that are connected using so-called Bézier curves. It is this latter method that generates the best results and that is used by most drawing programs.
To the right is an example of using Bézier curves
This drawing demonstrates the two principles. To the left, a circle is formed by connecting a number of points using straight lines. To the right, you see the same circle that is now drawn using 4 points (nodes) only.
Characteristics of vector drawings
Vector drawings are usually pretty small files because they only contain data about the Bézier curves that form the drawing. The EPS file format that is often used to store vector drawings includes a bitmap preview image along the Bézier data. The file size of this preview image is usually larger than the actual Bézier data themselves.
Vector drawings can usually be scaled without any loss in quality. This makes them ideal for company logos, maps or other objects that have to be resized frequently. Please note that not all vector drawings can be scaled as much as you like:
· Drawings containing trapping information can only be scaled up to 20 percent larger or smaller.
· Thin lines may disappear if a vector drawing is reduced too much.
· Small errors in a drawing may become visible as soon as it is enlarged too much.
It is fairly easy to create a vector based drawing that is very difficult to output. Especially the use of tiles (small objects that are repeated dozens or hundreds of times) and Corel Draw lens effects can lead to very complex files.
Applications that can handle vector data
There are hundreds of applications on the market that can be used to create or modify vector data. In prepress, Adobe Illustrator and Corel Draw are the most popular programs.
File formats that are used for vector data
Bitmap data can be saved in a wide variety of file formats. Oddly enough the most relevant formats for the printing industry are also capable of storing bitmap information:
· EPS: the most popular file format to exchange vector drawings even though PDF is quickly gaining ground.
· PDF: a versatile file format that can contain just about any type of data including complete pages.
· PSD: the native file format of Adobe Photoshop.
· AI: the native file format of Adobe Illustrator.
How to convert bitmap data to vector data and back
It is sometimes necessary to transform images from bitmap data to vector data or back. Some possible uses include:
· If you scan or photograph a logo, it is a bitmap image. If it is going to be used often in a layout it is more practical to have that logo as a vector drawing. That reduces its file size and you can change the image size without worrying about any loss in quality.
· Vector drawings often have to be converted to bitmaps if they will be used on a web page.
· Vector drawings are sometimes too complicated for a RIP to be output on film or plate. Converting them to a bitmap simplifies the file.
Luckily it is fairly easy to convert images from one mode to the other:
· From bitmap data to vector graphics: the process to convert a bitmap image to vector data is called outlining or vectorizing. Some drawing applications such as Adobe Illustrator and Corel Draw have this option built in. There are also separate programs available to vectorize bitmap images. For simple jobs the easiest solution is to put the bitmap image on the background of the canvas of a drawing application and manually draw over it.
· From vector graphics to bitmap data:
· Many drawing applications can store vector data as bitmap files as well (usually this option is hidden in the Export menu option).
· You can always view a vector file on screen, then take a screen capture and save this screen capture as a bitmap image.
· Photoshop can open some vector file formats and rasterize the file so that it becomes a bitmap file. A pop-up menu allows you to define the resolution and color mode of the bitmap data.
Demikianlah yang dapat saya sampaikan mengenai materi yang menjadi bahasan ini, tentunya banyak kekurangan dan kelemahan kerena terbatasnya pengetahuan kurangnya rujukan atau referensi yang kami peroleh hubungannya dengan ini. Penulis banyak berharap kepada para pembaca yang budiman memberikan kritik saran yang membangun. Semoga tulisan ini dapat bermanfaat bagi para pembaca khususnya pada penulis.
Referensi
https://www.lifewire.com/vector-and-bitmap-images-1701238
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