1. 8.2 PICTURE IT Graphic Types and Their Uses

2. What Are Graphics?  Graphics are pictures/images  They could be images taken on a digital camera or scanned from a magazine  They could be images drawn using a picture editing software  There are two main types of graphic – Vector and Bitmap

3. Pixels  All digital images are made up of small squares called pixels (PIcture Elements)  A digital photograph will be created using millions of pixels  There are approx 16 million colours available  The resolution of your screen tells you how many pixels will be displayed at any time

4. Bitmap  When you take a picture using a digital camera or scan an image you are creating a bitmap graphic  A Bitmap graphic is composed of many different parts known as pixels. It is possible to change each individual pixel on a Bitmap graphic  Bitmap graphics have large file sizes as the computer needs to save information about each pixel  When a Bitmap is resized the graphic loses quality

5. Pixelization When you resize a bitmap graphic the quality of the image is reduced. This is known as pixelization. The pixels which make up the image become clearer and the image may start to look blocky.

6. Vector  Vector graphics are created in graphics packages and are made up of objects. Each object can be edited separately i.e. Change shape, size, colour and position.  Vector graphics are scalable. This means that they can be resized with no loss to the overall quality.  This type of graphic does not store information about each pixel but instead uses mathematical relationships. This means the file size is kept small.  A Vector graphic does not look real – it tends to look like a cartoon

7. Scalability As the example shows. Vector graphics can be resized with minimal loss to quality. Clipart images are a good example of scalable graphics

8. Differences -Bitmap Vs Vector BitmapVector How are they formed? Made using different coloured pixels Objects are created using mathematics What can be edited? Pixels can be edited individually Individual objects File size Large file sizes due to computer having to save information about each pixel Small file sizes as equations are used to create objects Quality when resized?Quality is lost Quality remains constant even when resized Do they look real? Yes – photographs are a good example No – Often cartoon like. Clipart and autoshapes are good examples Common file formats.BMP.GIF.TIFF.JPEG.PNG.EPS.SVG.CGM

9. What are graphic formats?  Image file formats are standardised means of organizing and storing digital images.  Different formats mean different levels of quality and compression.  Compression makes the storage of data more efficient i.e. Smaller filer sizes  There are two types of compression  Lossless – quality remains the same  Lossy – components which would be invisible to the naked eye are removed meaning a small decrease in quality

10. Which should I Use?  When creating graphics there are a number of things to consider before choosing one format or another  Does the image need to be resized?  Does the image need to be drawn to scale?  Does the image need to look real?  Is file size important? I.e. Is it for use on a webpage?  It is important to remember that when creating graphics it is possible to combine graphic types

11. Software Tools  Most graphics software will allow you to work with Bitmap and Vector images  Common image creation software is MS Paint or Adobe Photoshop  Features of graphics software include: Cropping Adjust contrast and brightness Layering Cloning Special effects Colour adjustments Background removal