Creating Images for Print and for the Web

When creating or looking for digital images, it is very important to know how the image is going to be used. If an image is going to be displayed on a website, it is generally going to be shown at 72 pixels per inch (ppi). But if the image is going to be used in print media, the typical resolution is 300 dots per inch (dpi)*.

The means that image that 360 pixels wide will be 5 inches wide on a web page, but will only be 1.2 inches wide when added to a print document.

A 360 pixel image added to a 10 inch canvas @ 72ppi takes up approximately 25% of the canvas

The same image added to a 10 inch canvas @ 300dpi appears much smaller

Although the image is the same size (360 x 360 pixels) the resolution of the canvas has an obvious effect on the image. If we were to scale the image up, it would become pixelated and this would look unprofessional.

Therefore, we need to ensure that we work with the correct sized images from the outset and bear in mind that if the image is to be used in print media, we will need much higher resolution images.

---

*When describing screen density, we use pixels per inch (ppi). and when measuring print density we use dots per inch (dpi). However the terms are often interchangeable and may be used to refer to both. Although it is possible to measure density in pixels or dots per centimetre, the industry standard is inches. 

Basic Principles of 3D

2D images are defined as having height and width. In digital images the width of an image is defined by the "x" axis and the height by the "y" axis.

When describing image resolution we always state the width followed by the height. For example a high definition TV screen would be 1920 x 1080px.







In the early days of video games nearly all games were exclusively 2D.

This was mainly due to the limitations of the available hardware.

3D images have height, width and depth. The depth information is defined by the "z" axis.


Early 3D images were quite primitive, with little detail and no shading. As the technology improved, 3D graphics became more advanced.

Today 3D images can be seen in many forms from big budget movies such as Avatar and Toy Story to television adverts for products such as toilet duck. 





 Video games have also progressed to the point where the majority of big budget titles feature 3D graphics.

The next big development in 3D graphics is likely to be the use of glasses to produce stereoscopic 3D images.