Types Of Digital Graphics Used: Raster And Vector

In digital media, two types of digital graphics are used: raster and vector. Raster files are bitmaps, which are fixed grids of pixels that compose an image as each pixel is coded to a specific hue. Raster graphics are used in photographs, scans and detailed graphics. This is due to raster type images allowing for smoother colour gradients and more complex compositions than vector images. However, raster files are pixel based, which means that resizing the image in any way will lower the quality of the image. For example, when a raster image gets enlarged, it results in jagged edges as you can see the pixels that make up the image. This means that raster images are defined by a specific resolution, and as such are best displayed in that certain resolution. Raster images also have the drawback of being larger file sizes in comparison to vector files as the files have to contain information about each pixel in the image. Furthermore, a lossless raster file type such as a. psd file would have an even larger file size due to the information it's storing in order to allow the image to be edited in such a way that there is no pixel loss.

An example of a way to edit raster images are Photoshop and GIMP, which allow you to make precise edits to raster images. These are raster programs as they make pixel adjustments to images e. g. changing the colour of a pixel. However the more pixels added to an image through these programs, the higher the file size. This eventually makes the program run less efficiently. Examples of raster image file types include: JPEG, a lossy compression method results in degradation if repeatedly edited however has a very small file size; GIF, which is a lossless compressed filetype with animation capabilities, however the colour pallet is only 8 bit; BMP, an uncompressed bitmap native to the Windows OS; and PNG, which provides lossless compression and 48 bit true colour with and without alpha channel i. e. retaining transparency, at the tradeoff of a higher file size. Containers for well-known raster image editors are PSD and XCF for Photoshop and GIMP respectively.

In the context of 3D video games, raster images are best used for texture maps that you'll see closer up i. e. at a higher LOD. The drawback to them is that they make the game unnecessarily large due to their larger file size.

Vector

Vector files are images that consist of vector points and mathematical formulae conveying to the computer on how they connect to each other, resulting in primitive geometric shapes i. e. lines, squares, curves and circles. This means that a line that may take up an inordinate amount of pixels on a raster image, would only take the information of two points and the instruction to the computer to create a line between them. This also means that vector images are perfectly able to be enlarged in either direction. Because of this, vector images are not bound to a specific resolution and are instead bound by the resolution of the output device e. g. monitor and printer. However, the downside to vector images are that the colour depth achieved is much lower than that of a raster image. As well as this, vector images are unable to work with complex geometric shapes the way raster images can.