Unit 78, Exercise 3 Pixel's and Types of Digital Graphics

Level 3 Games Design

Unit 78: Digital Graphics for Computer Games

What is a Pixel?

A pixel is often represented as a square on many software's as it is such a simple shape and makes it easy to see each individual pixel when drawing on a computer. However as shown in this article by a former Microsoft employee "A pixel is a point sample. It exists only at a point. For a colour picture, a pixel might actually contain three samples, one for each primary colour contributing to the picture at the sampling point. We can still think of this as a point sample of a colour. But we cannot think of a pixel as a square—or anything other than a point. There are cases where the contributions to a pixel can be modelled, in a low-order way, by a little square, but not ever the pixel itself. An image is a rectilinear array of point samples". I like this quote as it goes into detail about exactly what a pixel is and is explained in such a way that it is easy to understand. You can find further information about the article here: Click Here for Article. This is an example of pixel art which uses pixels to create an image:

Types of Digital Graphics

There are two types of digital graphics, these are Raster and Vector images. A vector image is an image that is made up of polygons which allow you to have a much more detailed image, especially when you zoom in as it still keeps it's quality and stays sharp, you would use these images in a game when you want to use an image in different areas/levels however in one of them it is blown up/zoomed in so it still keeps it's quality.

Some different types of Vector images include: PSD (Photoshop) is where the image is saved from Photoshop and still has the layers that you made the image with you would use this in a game over anything else if you want to create a very detailed game where you can edit the tiniest detail and add shading to make it look better whilst sometimes actually making a layered effect for the background, WMF (Windows Metafile) was designed by windows to be used between applications however it uses both vector and bitmap, FLA (Adobe Flash) is content that can be affected by user interaction and AI (Adobe Illustrator) is the save file for a vector image created with the use of adobe illustrator, these vector images are best used for logos because it allows them to adjust the size of the image to fit different surfaces and still retain their quality.

You would only use these images for a system that uses a large storage as they take up a lot of space and therefore would not work on a phone or tablet. This is also a video explaining the differences: Click Here for Video.

This picture shows what a logo looks like in a vector image and a raster image and you can clearly see the difference in quality.

A Raster image is an image that is usually a rectangular grid of pixels, because of this when you blow up/zoom in to the image the quality of the image goes down as you start to see the pixels that make up the image that you are looking at therefore making it pixelated and at a lesser quality. You would use this in a game when you are using an image at the same size all throughout so it stays at the same quality.

Some different types of raster images include: BMP(Bitmap) is used to store images that contain one or more bits of information, GIF(Graphics Interface Format) a lossless format for image files that supports both static images and animations you would use this for when you want to insert a small animation or movie as it doesn't take a lot of storage but still retains the quality you want for a small animation, TIFF(Tagged Image File Format) is a common format for exchanging raster graphics images between application programs, it is also better than JPEG because it allows a better depth but is still compressed allowing them to be much better for phone games than JPEG images as it takes up the same space but has more quality and JPEG(Joint Photographic Export Groups) is an image format that is supported by the group, these raster images are best used for web graphics because they only need to be used at one size so it doesn't matter about the quality if you zoom in because that is not what they are used for.

You would use these images in a phone or tablet game because these files are compressed and take up less space but reduce the quality and phones and tablets don't have enough storage to use. This is a video explaining raster images: Click Here for Video. In real life raster images are often used for digital publication because it would not be a good quality if you were to print it out, however they can be used to reproduce photographs that can then be used for printing. For this information I used this website: Click Here for Website.