Samuels Ait exercise
- 1. Digital imaging or digital image acquisition is the creation of digital images. The term is often assumed to imply or include the processing, compression, storage, printing, and display of such images. The most usual method is by digital photography with a digital camera but other methods are also employed. Digital imaging was developed in the 1960s and 1970s. As digital technology became cheaper in later decades it replaced the older film methods for many purposes. An image changed on the computer would be called a digital image e.g. If a photograph was taken (which would be a natural photo) and then the person who took the photo wanted to tweak it, he would have to put it on a computer. After he finishes tweaking the photo it becomes a digital image instead of a natural image.
- 2. Raster Images A raster image, also called a bitmap, is a way to represent digital images. The raster image takes a wide variety of formats, including the familiar .gif, .jpg, and .bmp. A raster image represents an image in a series of bits of information which translate into pixels on the screen. These pixels form points of colour which create an overall finished image. When a raster image is created, the image on the screen is converted into pixels. Each pixel is assigned a specific value which determines its colour. The raster image system uses the red, green, blue (RGB) colour system. In photographs with subtle shading, this can be extremely valuable.
- 3. Vector Images Vector images are created on a computer using mathematical calculations. Vector images are used for simple geometric shapes like lines and arcs. These shapes can be combined to make squares and circles. Vector graphics is based on images made up of vectors which lead through locations called control points. Each of these points have a position on the x and y axes of the work plan. Each point, as well, is a variety of database, including the location of the point in the work space and the direction of the vector (which is what defines the direction of the track. This does not affect the size of the files in a substantial way because all information resides in the structure; it describes how to draw the vector.
- 4. Raster VS Vector Usually when choosing one of these image types the user would choose Vector images over Raster. This would usually be the case because Raster images are bury when magnified while Vector images are usually defined. As you can see with the image below Raster images have a blurred edge.
- 5. Image file Formats Image file formats are standardize means of organizing and storing digital images. Image Files are made up of digital data which can be rasterized for use on a computer display. An image file format can store data in uncompressed, compressed or vector formats. Once an image is formed the image becomes a grid of pixels, each of which has a number of bits to designate its colour equal to the colour depth of the device displaying it. A raster image file format can be displayed in many different formats, e.g. Jpeg, Exif, Tiff, Raw, Png, Gif,Bmp, Ppm, Webp, Jpeg 2000.
- 6. Jpeg file format The Jpeg file format is one of the most common image file formats used around the world. One of the main advantages of the Jpeg file format is that it is smaller in file size then most other image file formats. A disadvantage of the jpeg file format is that due to its small size it loses depth and quality. Gif file format Gif was the first image file format introduced into the world wide web. One of the advantages of having the Gif file format is that it is html supported. One of the disadvantages of the Gif File format is that it has restricted file colours.
- 7. Tif File format The Tiff file format is an image file format that mainly graphic designers use. It is a flexible and adaptable file format. The Tiff file is widely used as a bitmapped file format, which stores graphics in CMYK or RGB colour model. One of the advantages of using the Tiff format is that it is good for storing information for printing. A disadvantage. of using the Tiff format is that it takes up quite a lot of room up on the hard drive compared to other file formats.
- 8. References http://en.wikipedia.org/wiki/JPEG http://en.wikipedia.org/wiki/Graphics_Interchange_F ormat http://en.wikipedia.org/wiki/Tagged_Image_File_For mat