3.1.6: Application software used for presentation and communication of data

Graphics

What will you learn?

This presentation aims to help you learn two things:

› Understand how to discuss the advantages and disadvantages of using clip art images and collections of thumbnail images.

› Understand how to describe the difference between bitmap and vector images and which is suitable and when.

Clip Art

Clip art images are either supplied ‘free’ of charge with software packages or at a cost from the software manufacturer.› *free but you usually have to pay for the application!

They can be edited or used as they are and are usually easily downloaded through an application.

Clip Art and MS Office

Microsoft have an extensive library of clip art images.

Some images are quite good…and others are best left alone!

Clip Art (Pros and Cons)

Advantages Disadvantages

Images are ready when you are! Limited selection to choose from for a given topic.

Loads of images to choose from! The quality is quite diverse ranging from pretty good to not very good at all.

You can reduce costs because you don’t need to spend time designing new images and you don’t need to hire/employ a designer!

You won’t find a unique image – other people could use the same images as you do!

Extra equipment doesn’t need to be purchased – digital cameras, tablets, image software such as Photoshop.

A lot of clip art, especially when found online, is subject to copyright meaning you need to either ask permission to use it or you must pay for the right to use it.

Thumbnails

Thumbnails are used to show a library of images in a small space.

When you click on the thumbnail image the full size image appears.

Thumbnails

The aim of the thumbnail is to allow large collections of images to be browsed quickly.

Collections can have descriptions and categories making them easier to find.

They are usually low quality.› This allows them to load faster.

Microsoft Labs - Pivot

A new application by Microsoft is in development called Pivot which allows people to sort through data using images as a medium.

It uses thumbnail libraries to help convey information.

Microsoft Labs - Pivot

When you click on an area you are presented with thumbnails.

Click on a thumbnail and you are taken to a website (or websites) related to that image.

The more thumbnails you have though, the longer it takes to download them all.

Activity

List the advantages and disadvantages of using a collection of thumbnail images.

Advantages Disadvantages

Bitmap and Vector

There are different types of image that you can work with.

Bitmaps and Vector are two types which you need to learn about.

Both have their advantages and disadvantages which make them suitable for different things…but in order for you to understand those you need to understand what makes them different.

Bitmap images• Think of a Bitmap

image as loads of little squares which have their own colour.

• The squares are known as pixels.

• When a computer loads up a bitmap image it knows what colour to paint the pixels on the screen.

Bitmap Images

• This type of file is great for images that have a lot of detail in it.

• The more pixels an image has the more detail it has.

• We call the number of pixels a picture has the resolution.

Bitmap Images

• We start to encounter problems with Bitmap images when we try to change the resolution of our images.

• When we try to make images smaller the computer has to delete pixels in order for them to fit within the specified resolution.

• This can cause our images to degrade and we don’t see as much detail in the image anymore.

• When we try to enlarge our image it becomes blocky because the computer tries to guess what colour our extra pixels should be.

Going Smaller

Going Bigger

Compare original to newThis image was firstly reduced in sized and then made larger.

We have lost detail when we re-enlarged it because the computer removed some of the pixels when we downsized it!

When we re-enlarged it, the computer tried to guess what colours should be added...clearly it wasn’t the best guess!

Vector Images

• Vector images use a different method of drawing images.

• They use co-ordinates to draw lines.

• This means that images can be resized without loss of quality. All that happens is that co-ordinates are modified.

• However, they work best with simple images like clip art. They aren’t very good with complex images like the ones you take with your digital camera!

• Note: Not all images in the clip art tool are clip art images. You need to hold your mouse over the images to see what type of file they are.

Changing vector sizes

Other Image Formats

Bitmap (raster) › format made by Microsoft. › ideal use is desktop backgrounds on your PC.

Vector› Used for printing business cards, brochures, logos etc. › Easily embedded in other documents.

› Best for printing illustrations professionally. GIF (raster)

› The best choice for graphic images on the web. › Only uses 256 colours

Other Image Formats

• JPEG – Uses more colours than GIF – best choice for photos on the web. – Use to email photographs to people. – Small file sizes.

• TIFF – Very good for scanning and printing photos.– Used in commercial and professional printing. – Best for printing photos professionally.– A common format that can be used by most computers.

• WMF – Used for clipart. – Don’t support a lot of colours. – Not good for professional printing. – Used for drawing in Microsoft Windows.

Questions

Describe the difference between a bitmap image and a vector image.

Create a table which compares vector images to bitmap images. Each entry for vector should have a comparative statement next to it. For example:

Vector Bitmap

Can be resized without loss of quality.

Can’t be resized without losing some quality.

… …

Questions

Explain why a bitmap image is more suitable for photographs compared to a vector image.

Giving reasons, explain why an architect would be better off using vector images when he create blueprints for his next house design.