Misha Sillifant

Unit 19 Digital Graphics for Interactive Media

Definitions amd examples of digital graphics terminology 

 

Pixel (Picture Element) - An image is made up of millions of pixels, however they can not individually be seen due to the size of them. The pixels merge together to create a picture due to each individual pixel being a different colour. Some pictures can become 'pixelated' if there are a small amount of them creating the one photo, this is an example of a pixelated photo. 

 

 

 

 

 

Image resolution is the detail of the image. So if the resolution is higher this means that the image detail is then higher. This is then due to the amount of pixels that are in the picture, the more pixels the higher images resolution. The brightness of the pixel is called the intesity which then creates the overall brightness of the picture. 

 

Raster Image - Raster graphics is a grid made up of pixels (also known as a bitmap) and most images such as Web images and images taken from a digital camera are raster graphics. Raster graphics store lots of information meaning the larger the bitmap the larger file size that it will have. There are several file types of raster images for example JPEG (Joint Photographics Expert Group), GIF (Graphics Interchange Format), PNG (Portable Network Graphic), TIFF (Tagged Image File Format). JPEG is mostly used for still photos and is designed for compressing full colour or grey style digital images. GIF is used to compress both still and animated images. PNG is similar to GIF however it has better compression and supports more colours and TIFF is a computer file format for storing raster graphics images.

 

Lossy and Lossless - These are both types of compression. Lossless is when all the data that was in the file that was compressed remains after the file is uncompressed, GIF is a file type that contains lossless. Lossy is when unimportant information is deleted once compressed to allow the file size to shrink.

 

Vector Images - They are created on graphics editing programs by many lines, curves, points and shapes (such as polygons) which produce a picture or graphic image. An EPS (Encapsulated PostScript) file is often used for transferring files between various graphics applications. AI are file types that are used in Adobe Illustrator and were created by Adobe to make it possible to show EPS files. An FLA file is used for Adobe Flash, the Adobe Flash authoring software can edit FLA files and convert them into SWF files. This is because SWF files can then be viewed on most internet browsers if the Flash plugin is installed.

 

Bit depth (Bits per pixal) - This is the colour information within a picture. This means that if the bit depth is higher then the more colours it would be able to contain. If an image is black and white this means it is a 1 bit image meaning it can only show two colours at a time, this is also known as a monochrome. However a highcolour contains 15 bits meaning it can show a lot more colour and a truecolour containing 24 bits which again produces even more colour.