Page 10 - DCAP109_GRAPHIC_TOOLS

Unit 1: Computer as a Design Tool

TIFF, PNG, and GIF, also store bitmap images (as opposed to vector graphics), but they are not Notes
usually referred to as bitmaps, since they use compressed formats internally.

Vector Graphics

Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or
polygon(s), which are all based on mathematical equations, to represent images in computer
graphics.
Vector graphics formats are complementary to raster graphics, which is the representation of
images as an array of pixels, as it is typically used for the representation of photographic
images. There are instances when working with vector tools and formats is best practice, and
instances when working with raster tools and formats is best practice. There are times when
both formats come together. An understanding of the advantages and limitations of each
technology and the relationship between them is most likely to result in efficient and effective
use of tools.

Figure 1.1: Effect of Vector Graphics versus Raster Graphics

The original vector-based illustration is at the left. The upper-right image illustrates magnification
of 7x as a vector image. The lower-right image illustrates the same magnification as a bitmap
image. Raster images are based on pixels and thus scale with loss of clarity, while vector-based
images can be scaled indefinitely without degrading.

Overview of Vector Graphic

Computer displays are made up from small dots called pixels. The picture is built up from these
dots. The smaller and closer the dots are together, the better the quality of the image, but the
bigger the file needed to store the data. If the number of pixels is kept constant, the size of each
pixel will grow and the image becomes grainy when magnified, as the resolution of the eye
enables it to pick out individual pixels.
Vector graphics files store the lines, shapes and colours that make up an image as mathematical
formulae. A vector graphics program uses these mathematical formulae to construct the screen
image, building the best quality image possible, given the screen resolution. The mathematical
formulae determine where the dots that make up the image should be placed for the best results
when displaying the image. Since these formulae can produce an image scalable to any size and

LOVELY PROFESSIONAL UNIVERSITY 3