1. Raster Images . Raster is one of two kind of computer graphics. Raster images can also be called bitmap images. Raster is generally a rectangular grid of pixels. Raster graphics are resolution dependant, they deal more practically than vector graphics with photographs and photo – realistic images, while vector graphics are normally better for graphic design. Painter, Photoshop MS Paint and so on, revolve around editing pixels. These are all raster based. A raster image editor works by manipulating each individual pixel. Raster graphics can be scaled down without a loss of quality, but enlarged, it tends to love ‘pixelated’. A raster file is usually bigger than a vector file. Raster file types are; BMP, TIFF, GIF and JPEG files. You can convert a Vector image into a Raster. This is called Rasterization. It means taking an image described in vector graphics and converting it into a Raster image. This is so it can be shown in a video or print. When blown up, the pixels in a raster image become apparent. While this effect is sometimes a deliberate choice on the part of an artist, it is usually not desired. Depending on resolution, some raster images can be enlarged to very large sizes, while others quickly become difficult to see.
2. Vector Images . Vector graphics works as shapes. They are often used for things such as company logos as they need to be scaled to different sizes. Vector graphics use mathematical relationships between the points and paths that connect the image. A vector image remains smooth at any size. Programmes that are vector based are PostScript and TrueType. A vector graphics editor is used for editing and creating Vector graphics. The image can be changed by editing screen objects. Mathematical operators can be used to stretch, twist and colour component objects in the picture or the whole picture. Vector graphics are made up of many individual objects. Each of these objects can be defined by mathematical statements and has individual properties assigned to it such as colour, fill, and outline. Vector graphics are resolution independent because they can be output to the highest quality at any scale.
3. Anti aliasing. Anti aliasing means sampling something smooth and ongoing using a number of measurements. In Photoshop, there is a box at the top of the screen telling Photoshop about the colours and what needs to be changed etc. Anti aliasing get rid of the jagged lines. Anti Aliasing is used by people who want to perfect an image so it has no un – even edges. It also makes your images more high quality. To me, Anti aliasing means fooling the eye into thinking a jagged line is actually smooth. Anti aliasing works along side with rasterization. If you don’t use Anti aliasing and just adjust the size etc, you could lose the sharpness of the image completely. You can do this process on Adobe Photoshop mostly – there are four levels of smoothing available for the user which are, smooth, strong, crisp and sharp.
