What Is a Graphics Editor?

Graphics editors are programs for creating and editing graphic documents, i.e. documents with images - whether these be photographs, logos, signs, or anything else. There are, however, two basic ways in which computers can work with images - as vectors or as bitmaps.The difference between these approaches is so large that most graphics editors specialize in one of them, and can handle only the most essential functions from the other type - usually they can only import and place the other type, perhaps also reduce and enlarge it. Zoner Draw 4 is a vector graphics editor. But since it is designed especially for those users who do not care to buy expensive programs aimedat professional users, it also contains some of the most frequently used tools for editing bitmaps.

Vectors and Bitmaps

Both of these approaches for storing images are important. They are both irreplaceable for graphics creation, and they also supplement each other. Once you understand the two approaches, you will then be able to distinguish between them, and decide when and for what each of them is important.

Vector Graphics

...are based on mathematical descriptions of flat shapes - on geometry. This approach sees images as collages of objects (lines, texts, geometrical shapes, etc.), made up of "tangent vectors" or "guidelines". (Mathematically speaking, a vector is a directional segment defined by its length, its direction, and the position of its starting point). The computer thus records this data, as well as other properties (color, shadow, etc.) for basic objects and recalculates the shapes of vectors every time they are redrawn or printed. Therefore, the display quality is always high, regardless of the magnification level used, the printout quality is always as high as the printer will allow, and drawings don't need much disk space.

Bitmap Graphics

...are based on the way images are displayed and printed. This approach, therefore, sees the images as a mosaic of points - a "bit map", thus "bitmap", where every point, called a "pixel", is defined by its position and color. The computer must remember this information for every point; this causes bitmap data files to grow in proportion with the image's size. Increasing the size of a bitmap image also causes a significant decrease in its quality.

Graphics File Formats

The picture below illustrates the difference between how vector and bitmap images appear after enlargement (on the left: an image in vector format; on the right: the same image as a bitmap; the oval inside of each image is an example of its original dimensions):

There are many ways to store images in files, both for vector and for bitmap images. Each such way is called a format. This aspect of graphics is described in more detail in the chapter on working with files, but we should mention at least some basic facts here.

For bitmap images especially, the choice of formats is very important, because the relation between image quality and file size forces compromises - the only way to reduce their size is to reduce the amount of information for each pixel. It is necessary to set priorities for every purpose (one set for the Internet, another for DTP, etc.) and to decide based on these. The situation is different for vector formats, where this problem does not normally exist. Note, however, that a large (but shrinking) number of DTP studios do not accept vector-format files, and that only a special vector format, SGC, works on the Web, and not all browsers support SGC. Therefore, Zoner Draw offers export to bitmap formats.

Which Is Better: Vector Graphics or Bitmap Graphics?

Although the above information speaks against bitmap graphics, they are irreplaceable in DTP (most printers use the bitmap approach), on the Internet (Web vector graphics need a special format, and many browsers do not display them), and when using videos and photographs (their output is a bitmap or series of bitmaps).

The Elements of Vector Graphics

Vector graphics are special mostly because each object is made up of simple (fundamental) elements, and it is always possible to break an object down into these elements and edit the object on the level of these elements.

A CURVE is the lowest object in the hierarchy that can be drawn. By "curve" here, we actually mean a Bézier curve, which comprises one or more - straight or curved; multiple, connected, or merely grouped - lines.

A GEOMETRIC SHAPE is a closed shape with borders made up of a curve. In geometry, this could be, for example, a square, a rectangle, a triangle, or a hexagon. In vector graphics, we perceive geometric shapes somewhat more generally. Besides mathematical polygons, this can be any shape with borders made up of any type of curve; the only condition is that the curve must be closed. Every vector graphics editor offers a selection of tools for easily drawing basic shapes - these generally include squares, rectangles, n-polygons (with a defined number of equal sides), circles, ellipses, and sometimes also stars (with a defined number of peaks). In Zoner Draw 4, however, you can also create entirely irregular shapes. Some segments of the border curve can even cross each other.

A GROUP is a collection of multiple objects that behave as a single object. This often significantly simplifies work and creates interesting effects. Besides simple object grouping, you can create combined groups and blends between objects.

TEXT is a very important element of vector graphics. Most graphics editors lets you add text to documents, and the majority of them also offer a certain spectrum of editing options as well as formatting for longer, continuous texts using, for example, a table. At the same time, however, a text object can also be converted and edited on the level of the individual curves that define the shape of each character.