Bitmaps vs Vectors

  Bitmaps vs Vectors

What You Need to Know

Digital images for the most part are broken down into two distinct categories. They are either bitmaps or vectors. If you work in print, you need a good understanding of the advantages and disadvantages of both file types.

  • Generally digital pictures and scanned images are bitmap files also called raster images.
  • Art created in applications like Adobe Illustrator or Corel Draw saved as vector graphics.

Technically both file types are completely different, however, can look virtually identical in on a computer screen in either format. Basically bitmaps are used as photographic images whereas vector graphics are more often used for abstract images such as logos. There are however many exceptions to this rule. Often times it is nearly impossible to determine whether an image is bitmap or vector just by looking at it.

It is possible to convert a bitmap image into a vector file. A vector file type can be transformed into a bitmap. Additionally, there are file formats that combine both types into a single file.

Bitmap images

Bitmap images are what their name says: 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). A good example is looking through a magnifying glass at a newspaper to expose the dots that create an image on paper.

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.
  2. Grayscale images.
  3. Full Color Image

 


 

 

Grey Scale Image Zoo Printing

Grey Scale Bitmap Image

Line Art Image Zoo Printing

Full Color Bitmap Image Zoo Printing

Bitmap characteristics

Bitmap files are very large, for example a CMYK A4-size picture that is optimized for medium quality printing (150 lpi) takes up 40 MB The main disadvantage of bitmap images: once they are enlarged too much, they look unnatural and lose a lot of detail. Decreasing their sizes may also have an impact on image quality as images lose sharpness.

Applications for bitmaps

There are hundreds of applications on the market that can be used to create or modify a bitmap file. In prepress, like – Adobe Photoshop – who dominates the market. However there are alternative less

expensive programs like Corel Photo-Paint, should be disregarded.


Vector graphics

Each individual line is made up of a vast collection of points with interconnecting lines or just a few control points that connect using Bézier curves. Bézier curves generate the best results and is used by most drawing programs.

Vector characteristics

Vectors are small files because they only contain data about the Bézier curves that form the drawing. A EPS file format that is often used to store vector drawings includes a bitmap preview image along the Bézier data. The file size of the preview image is always larger than the actual Bézier data itself.

The great advantage of a Vector drawing is that they can usually be scaled without any quality loss. Therefore, making them perfect for company logos, maps or huge art pieces that need to be resized frequently.

Applications that can handle vector data

There are many applications on the market today that can handle vector files to create or modify vector data. In prepress, Adobe Illustrator and Corel Draw are the most popular ones.

Zoo Printing

Knowing the difference between both files types for graphic images can make your print jobs run smoothly and on time minimizing production issues. If you are a print broker or graphic designer just starting out or a long time professional you can rest assured Zoo Printing will help you with any troubled files you might have. The Zoo Printing Customer Support Team & Prepress dept. is there to help you every step of the way if needed.

 

ZOO POST BY FRED A. SMITH

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