Different Image File Formats
There are different types of image file formats, which all include different areas, for example. Some may be of bigger size images then others, some are used for different type of images. JPG (Joint Photographic Experts Group) is commonly used for photographs where as, GIF are used for small icons, texts, images containing animations etc. JPG is used to save an image and to upload it successfully on the internet. JPEG uses compression photographic images which, includes splitting the original image into minute pixel blocks, which are halved more and more until it fulfils the desired amount of compression. JPEG's can hold up to 16.7 million colours without the use of paletts, which was designed for highly detailed 'photorealistic' images. PSD is used to create and edit images on Adobe Photoshop, where it saves all layers of texts, images and you can go back to and edit and annotate onto. TIFF (tagged image file format) which contains tags, which is a flexible & adaptable format which allows many image processing applications, which is specifically designed for monitors, scanners & printers. GIF (Graphics Interchange Format) which is widely used for transmission of images across data networks. Which displays 256 colours which makes it unsuitable for images with included continuous colours. This type of format is best used for clip art, or black & white line drawings. This format includes ways of transparent areas, colours in detached areas, buttons on sites & small icons.
An example of a high resolution JPEG
Raster and Vector images
The differences between 2D graphics Raster & Vector images:
All electonic art images are divided into two groups: Raster (bitmap) or Vector images. Raster images are composed of connected dots, where as vectors use connected lines in the images. Raster
Raster images are of a collection of dots also known as pixels. A Raster image also known as 'bitmap', is a way that you can represent digital images. When a raster image is created, the image will be converted into pixels, which each individual pixel adds to the colour. Raster images holds the colours Red, Green & Blue (RGB) in the system. An RGB of the value 0,0,0 would be the colour black, & the values go up to 256 for each colour, allowing a variety of different colours, which is valuable in photographs with subtle shading. This graphic type is good when manipulationg & editing, or adding special effects to an image. They shouldn't be used if the image is of high quality which needs to be maintained for the image scale & where transparent backgrounds are preferred. Scanned Graphics & web graphics (JPEG & GIF Files) are most common forms of raster images, and there are also the following files which are raster images: BMP, TIFF, PSD. Popular bitmap programmes are, Adobe Photoshop, Microsoft Paint.
On the other hand, Vector images are a collection of connected lines and curves & shapes with joints and paths other then pixels, which enhances higher image quality. Vector graphics are editable & scalable, which gives the ability to resize and edit objects and also customize colour & texts, you can also add information onto, without any loss of quality! However, it's not possible to create a 'realistic' looking image as vector images are made up from solid colours. Also an object can be modified by not only changing attributed but also transforming and shaping. Vector images as they're scalable, are resolution indepedent, which you can decrease & increase as you like and the lines will the lines will remain sharp, on screen and printed.
How Images are displayed
Images are displayed differently on screen compared to on paper. There are two different colour formats, one is CMYK which is colour scale which is used to print & RGB which is the colour scheme of the image, which is seen on the computer screen.
Hue & Saturation: Hue is another name for Colour, for example a low Hue number, will result in the image appearing black & white. When changing/adjusting the Hue (colour) of the image, the base colour changes in correlation with the colour wheel. The saturation of the image refers to the intensity of the colours. When adjusting the hue & saturation it enhances & changes the colour of the image. An image can be dull & dark, but in contrast, once slightly changing the Hue & Saturation, the image is transformed to a brighter, enhanced image. 
CMYK: CMYK is the settings of the colours of what the printer will print out. Most printers are set to this & will print in this format. The colours which stand for CMYK & used for printing is; Cyan, Magenta, Yellow & Black, these four colours work together, which mix to get the right colour to appear on a page, similar to mixing paint to achieve a certain colour.
CMYK is used for digital printing, however it may not be able to re-produce every exact colour identically to what is seen on the screen, as the colours are limited to a certain standard when making colours with the four colours themselves.
With CMYK to produce the colour black, the value is at the highest of CMYK of 100, where as the colour white is the value of 0. This is opposite in contrast with RGB, & this shows how they work differently on paper & on screen.
Grayscale: Gray scale is more or less Black & White image. You can convert a colour image to greyscale by tools/changing the hue & saturation on Photoshop. By altering the hue/saturation & contrast/brightness you can achieve an effective image of grayscale. Grayscale is composed exclusively of shades of gray, varying from black at the weakest intensity to white at the strongest. Grayscale images can be by the result of measuring the intensity of light at each pixel in a single band.
