Vector graphics

Vector graphics. Drawing programs like Adobe Illustrator create vector graphics made up of lines and curves defined by mathematical objects called vectors. Vectors describe graphics according to their geometric characteristics . For example, a bicycle wheel in a vector graphic is formed from the mathematical definition of a circle drawn with a certain radius, at a specific position, and with a specific fill color. You can move, resize, or change the color of the wheel without losing the quality of the graphic.

Vector graphics does not depend on resolution; that is, they can be scaled to any size and printed on any output device at any resolution without losing precision or sharpness. Therefore, vector graphics are the best choice for text (especially small text) and bold graphics, such as logos, which need to keep lines sharp when scaled to different sizes.

Because computer monitors represent images on a grid, both vector and bitmap images appear on the screen as pixels.

There are different programs to deal with these two types of graphics. Programs like Photoshop or Paint Shop Pro work on bitmaps. These programs are more focused on photographic treatment and retouching. Other programs, such as Illustrator or Corel Draw work with vector graphics. These programs are most used to create images from scratch, although what we think we later convert to a bitmap, saving it as a gif or a jpg.

  • Illustrator also allows us to generate a vector graphic from a bitmap. We will see all this throughout the course.

A vector image is a digital image made up of independent geometric objects (segments, polygons, arcs, etc.), each defined by different mathematical attributes of shape, position, color, etc. For example, a red circle would be defined by the position of its center, its radius, the line thickness and its color.

This image format is completely different from the format of bitmap images, also called matrix images, which are made up of pixels. The main interest of vector graphics is to be able to enlarge an image at will without suffering the loss of quality that bitmaps suffer. In the same way, they allow images to be moved, stretched and twisted relatively easily. Its use is also very widespread in the generation of images in three dimensions, both dynamic and static.

All current computers translate vector graphics into bitmaps so that they can be represented on the screen as it is physically made up of pixels.

Summary

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  • 1 Main applications
  • 2 Vector graphic formats
  • 3 Printing
  • 4 Advantages and disadvantages
    • 1 Advantages
    • 2 Disadvantages
  • 5 Vector Graphics Editor
  • 6 Sources
  • 7 See also

Main applications

  • Graphics generation

They are used to create logos expandable at will as well as in technical design with CAD-type programs (Computer Aided Design). Very popular for generating 3D scenes. Document description languages ​​Vector graphics allow you to describe the appearance of a document regardless of the resolution of the output device. The best known formats are PostScript and PDF. Unlike matrix images, these documents can be viewed and printed without loss in any resolution.

  • Typefaces

Most current applications use text consisting of vector images. The most common examples are TrueType, OpenType, and PostScript.

  • Video game

In 3D video games it is common to use vector graphics.

  • Internet

Vector graphics found on the World Wide Web are usually in either open VML and SVG formats, or SWF in proprietary format. The latter can be viewed with Adobe Flash Player.

Vector graphic formats

  • Proprietary – Some of them have fully or partially open specifications
  • PostScript ® (PS, EPS (Encapsulated PostScript))
  • SWF Adobe Flash ®
  • DXF, Drawing eXchange Format and DWG, Autodesk AutoCAD formats.
  • HPGL: (HP Graphic Language), A de facto standard for plotters (Plotters).
  • Adobe Illustrator AI
  • Paint Tool UPS
  • Corel Draw CDR ®
  • FH9, FH10 and FH11
  • IGES
  • Windows Metafile (WMF)

Print

A key point of vector images is their practice fine-tuning at the time of printing since it is possible to scale them and increase their definition unlimitedly. For example: you can take the same vectorized logo, print it on a personal card, and then enlarge it and print it on a fence, maintaining the same level of quality in both images. The most popular examples of document formats to be printed are PDF and PostScript.

Another application where vector graphics are important is cutting chat, since this, as its name indicates, cuts color areas designed by the user from a digital file. These figures are built from vectors that are interpreted by the plotter as the limit lines through which the blade that cuts the material must pass.

Advantages and disadvantages

Advantage

Depending on each particular case, vector images may require less disk space than a bitmap. Images made up of plain colors or simple gradients are more likely to be vectorized. The less information to create the image, the smaller the file size will be. Two images with different presentation dimensions but with the same vector information will occupy the same disk space. They do not lose quality when scaled. In principle, you can scale a vector image unlimitedly. In the case of matrix images, a point is reached where it is evident that the image is made up of pixels. Vector-defined objects can be saved and modified in the future. Some formats allow animation.

Disadvantages

Vector graphics are generally not suitable for encoding photographs or videos taken in the “real world” (Nature photographs, for example), although some formats support mixed composition (vector + bitmap). Virtually all digital cameras store bitmap images. The data that describes the vector graphic must be processed, that is, the computer must be powerful enough to perform the necessary calculations to form the final image. If the data volume is high, the image representation on the screen can become slow, even when working with small images. No matter how much an image is constructed with vector graphics, its display on screen, as in most printing systems, ultimately has to be translated into pixels.

Vector Graphics Editor

A vector graphics editor is a computer application that allows the user to create and edit vector graphics images interactively on the computer screen (compared to MetaPost) and save them in one of the many vector graphics formats, such as EPS, PDF , WMF, SVG or VML.

JPEG files are normally photographs. They show continuous variations in color and tones throughout the image. In vector format, on the other hand, line and shape stand out in general. They are often art illustrations, or art sketches like maps. JPEGs cannot be enlarged without degrading the image resolution, while vector files can be enlarged without any loss of quality. There are programs (like Genuine Fractals) that use complicated algorithms to enlarge JPEG images as if they were vector images, but there are ways to approach the same result in Photoshop.

 

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