Image File Types

GIF FILES
What are they used for?
Gif files are considered the most popular form on the internet and in fact and are the most excellent for formatting compressed areas or images with large areas of the same colour. But this type of format is considered the easiest option in order to be able to post animation online.  The Gif89 format is  able to support transparency and interlacing.

The idea behind originally designing GIF files was to create the smallest possible image file for uploading and downloading from electronic Bulletin Board Systems thus producing a highly compressed format that minimises file transfer time over phone lines.

The most common way of reducing the size of GIF files would be to reduce the number of colours on the palette. However it is important to note that GIF already uses the LZW compression scheme internally to make images as small as possible without having to loose any data.

A GIF file is a file format for storing graphical images.

What is their colour depth?
A gif image is able to reach the maximum resolution and bit depth of: 256 colours and 8 bits.
File Size Characteristics?



JPEG FILES
What are they used for?
JPEG stands for Joint Photographic Experts Group.
JPEG files are used in a variety number of image file formats. This type of format is most commonly used by digital cameras and other photographic image capture devices. This type of format is the most common format and is basically used to store and transmit photographic images via the World Wide Web.

Remember a Jpeg photo is always compressed therefore some of the photo's original information will be lost.

Colour Depth?
A JPEG file contains 8 bits of colour for each colour channel.It means that a primary colour ( R G B) can have 256 (28) different intensity values. Mixing of primary colours leads to 16.8 (256x256x256) million different colours.
File Size Characteristics?


Animated GIF files, where are they used?
An animated Graphics Interchange Format (GIF) file is a graphic image on the Web which moves. It is used to create a twirling icon or a banner with a hand that waves or letters that magically get larger. This sort of file is specified as GIF89a that contains a single file with a set of images that are presented in a specified order. An animated GIF can loop endlessly or it can present on or few sequences and then stop the animation.

In order to create this sort of file you need to creat a series of images, each slightly different from the one before. These series of GIFS are then put together in order and are layered one on top of the other in a photo or illustration editing program.They are then layered in reverse order with the last image on top. Finally loop and speed are set to these images to create an animation.

Basically these types of files are established to create an animation through the steps listed above.
Colour Depth
 File Size Characteristics


MPEG Files
What are they used for?
MPEG stands for Moving Picture Experts Group. It is used to refer to the family of digital video compression standards and file formats developed by the group. MPEG generally produces good quality in video format.MPEG algorithms compress data to form small bits that can be easily transimitted and then decompressed. MPEG achieves its high compression rate by storing only the changes from one frame to another, instead of each entire frame. This video information is then encoded using a technique called Discrete Cosine Transform. MPEG uses a type of lossy compression, since some data is removed. However this removal of data is barely noticeable by the naked eye.
Colour Depth?
File Size Characteristics?

What is a Vector Based Map
Unlike the other types of files listed above Vector images are not made of a gride 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 even a curvy shape. These paths can be used to create simple drawings or complex diagrams. Paths are even used to define character face types.
Due to vector based images not being made of specific dots, they can be scaled to a larger size without loosing the quality of their image. For example if you were to blow up a raster graphic then it would look pixelated. However if you were to do this to a Vector graphic then the edges of the object within the graphic will stay smooth and clean. Many flash animations also use vector graphics since they scale better and take up less space.
 Vector Based image extablished on inkscape.

 A Gif image.

 JPEG image

 animated gif.