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.
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.
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.
Image resolution describes the detail an image holds. The term applies to raster, digital images film images, and other types of images. Higher resolution means more image detail.
Image resolution can be measured in various ways. Basically, resolution quantifies how close lines can be to each other and still be visibly resolved.
Resolution has a huge impact on an image. For example, in Photoshop we usually have to adjust the resolution levels so the image is the best quality possible. If the picture has low resolution, it’s sometimes very clear to see and noticeable.
An aspect ratio is the ratio of the width of the image to it’s height. Different ratio’s are used when it comes to films showing on a cinema screen, blu – ray and DVD. 4:3 standard is used for normal television and is the standard size and 16:9 standard is mostly used for HD TV. The number has to be greater as with HD the image you see is a lot clearer than normal so you would be able to notice if the image had just been stretched.
Below are the most common aspect ratio’s used today.
There are many different types of File Formats. There are different ones for things such as Adobe Photoshop, Microsoft Word and so on. The main File Formats are listed below;
Jpeg is mainly used in things such as Adobe Photoshop and Adobe Illustrator. It changes the format to enable you to view your work as an image instead of viewing it on the program you created it on.
Tiff means Tagged Image File Format and is a file format for storing images. This format is mostly used when doing image manipulation related things.
Eps, shortened for Encapsulated PostScript is a programme that enables you to edit things into a useable graphics file format. Eps was pretty much the first version of Adobe. This was the basic alternative. People who use this are graphic art designers.
PDF is what people use when they want to exchange a file, for example, so you can view it easily in a number of documents. You can also PDF things to show them clearer and bigger.
There are two types of colours used in Adobe, CMYK and RGB. These two are used because you can change the way your work is viewed, for example, you can control how much light you want etc. These two colours are used all the time in Adobe Photoshop.
Adobe Photoshop is used for many things these days. For example, it can be used for simple things such as editing the colour and adjusting the contrast on your picture to more advanced things such as manipulating an image. There is an endless list of things you can do on Photoshop. Photoshop is used in many situations. It’s used mainly in the celeb world. The term ‘photo shopped’ has been said a lot. This is when a celebrity has had their picture edited to make them look flawless, for example you can take away imperfections and make the image to a certain extent, how you want it to look. You can also add text on Photoshop and merge two images together. Every so often a new updated Photoshop version comes out.
Adobe Illustrator deals with vector graphics and enables you to do more technical things. For example. You can make certain shapes and add them into a picture. You can also edit the scale of your page and make mood boards etc, I think a good thing about Illustrator is whilst creating a mood board, if you have an image on there, you can edit the size of the image without the pixels going weird making the image blurred.
Adobe InDesign is run by Adobe Systems as well as Illustrator and Photoshop but InDesign is more for making brochures and leaflets etc, it’s more for the advertising side of things. Adobe InDesign is set out quite similar to Photoshop in that all of the icons etc are on the left side of the screen and all together so I think it would be quite easy to use if you were to be quite familiar with Photoshop already. I think Adobe InDesign is a little more technical that Illustrator and Photoshop because as text is a main part of Adobe InDesign there are more features.