Graphics

Active vocabulary

Raster - Растр Vector - Вектор Pixel - Вектор Scale - Масштаб Grid - Сітка Sketch - Ескіз

Bitmap - Бітова карта Resolution - Резолюція Grainy - Зернистий Limitation - Обмеження Convenient - Належний Determine - Визначати

Jaggies - Нерівності Skew - Нахил Digital - Цифровий Curvy - Вигнутий Sharpness - Різкість Blocky - Масивний

Discussion

Think of different spheres and branches where graphic packages are used. What are they used for? And why do they have a selection of tools? What are the disadvantages and advantages of graphic design? Why do magazines use graphic packages?

Reading

Read the text below and answer the following questions

● Explain how bit-mapped packages work?

● What are the main problems with using bit-mapped packages?

● What is an advantage of using a bit-mapped package?

● Explain how vector packages work?

● What are the main problems with using vector packages?

● What is an advantage of using a vector package?

There are two kinds of computer graphics - raster (composed of pixels) and vector (composed of paths). Raster graphics are digital images represented by a matrix or grid of pixels commonly called a bitmap. Each pixel or dot displays a unique color and together all of these colored dots create an image. Every pixel in a bitmap is stored as one or more bits in computer memory. Raster graphics with a greater number of colors and pixels will require more bits and take up more memory. Typical file formats for raster graphics include .jpg, .gif, .tiff, and .bmp.

Since raster graphics are represented in a grid structure, the width and height are usually indicated by the number of rows and columns rather than a particular unit of measurement. The size of an image might be described as 640 x 480 meaning that there are 640 pixels in a row and 480 pixels in a column. The resolution or degree of sharpness present in an image is calculated by determining the number of pixels per inch (PPI) or dots per inch (DPI). A higher resolution raster graphic will have smaller pixels that result in a more detailed image. When raster graphics need to be displayed or printed at larger sizes, it is helpful to use a higher resolution so that the image does not appear grainy. Raster graphics are convenient in that they can represent photo-realistic images quite easily, but they have limitations. Because the pixels are arranged in a regular pattern, weird moire patterns can appear if they are displayed on a monitor incorrectly, or if they represent an image with a regular pattern that interacts badly with the pattern of the pixels. Likewise, if the resolution is too low and the contrast is too high, certain pixels can stand out and leave the image with the “jaggies.”

Unlike .jpg, .gif, .tiff, and .bmp images, vector graphics are not made up of a grid of pixels. Instead, vector graphics are comprised of paths, which are defined by a start and end point, along with other points, curves, and angles along the way. A path can be a line, a square, a triangle, or a curvy shape. These paths can be used to create simple drawings or complex diagrams. Paths are even used to define the characters of specific typefaces.

Because vector-based images are not made up of a specific number of dots, they can be scaled to a larger size and not lose any image quality. If you blow up a raster graphic, it will look blocky, or "pixelated." When you blow up a vector graphic, the edges of each object within the graphic stay smooth and clean. This makes vector graphics ideal for logos, which can be small enough to appear on a business card, but can also be scaled to fill a billboard. Common types of vector graphics include Adobe Illustrator, Macromedia Freehand, and EPS files. Many Flash animations also use vector graphics, since they scale better and typically take up less space than bitmap images.

Language practice

1. Decide whether the following statements are true or false:

1. When enlarged, images produced by a drawing package will look pixelated / jagged. 2. Drawing packages are the most expensive type of graphics package. 3. A drawing package stores images by remembering the properties of the objects that make up the image. 4. Drawing packages are used to design three dimensional objects.

True/False True/False True/False True/False