How I Created My DVD Template

Difference Between Vector & Bitmap Based Graphics

In our weekly lessons we have currently moved on from Photoshop tutorials to Illustrator tutorials. The main difference between Photoshop and Illustrator is that Photoshop deals primarily with Bitmap graphics and Illustrator deals with Vector based graphics. 

Bitmap graphics are made up of pixels whereby each pixel has colour data recorded for it. This colour data is recorded as bits of information. The file size for a bitmap image is typically large as data is required to be stored on every single pixel. A bitmap image when enlarged loses resolution and starts to look blocky and “unattractive”.

Vector graphics on the other hand use mathematically defined objects. For example in a square box that is 100 pixels by 100 pixels in a bitmap each of those pixels will need to have a colour associated with it. That is 10,000 pixels normally requiring a 24 bit colour code for each one. In a vector based box then what would need to be stored is the x and y co-ordinate of 4 box corners. A colour code for the fill of the box, assuming it is uniform. Then a colour code and thickness of the “stroke” or line that connects the corners. This is much less data! 

So vector graphics can store data far more efficiently than bitmap graphics. Vector graphics are also scalable in a way that bitmaps are not. As the vector object is stored as part of a mathematical set of values then extra formulas or calculations can be done very easily  on the object, ie make the object twice as large or half as large. As this is not performed at a pixel level then scaling up even 1000 times does not affect the way in which any edges are defined. Scaling up a bitmap image even by a factor of 10 will often make the picture appear very blocky. Vector graphics will look just as good when scaled either very large or very small. 

However when it comes to highly detailed pictures (ie high res photo’s) then vector graphics are no longer suitable as each pixel is likely to be different. Vector graphics are really good where blocks of colours are going to be used, ie logo’s or trademarks. 

 

Creating A Template For My DVD Label

Having looked for an accurate size of a dvd I was able to locate this image on the internet which gives the exact guides for a standard DVD disc.

In illustrator I set up a new artboard with dimensions 210mm by 210mm. This would allow some space around the outside if I needed it for anything but would still fit on an A4 page. 

I then set up guide lines at 105mm (half of 210mm) on both the x and the y axis. This gave me the exact centre of the artboard (page). 

Then I select the elipse tool in Illustrator and left click on the centre to bring up a box which allows me to enter the size of a circle. I set this to 125.5mm which is the overall max diameter of a disc. 

Then I check that this is correctly centred onto the centre point. Once happy it is centred (it should be by default) I add it as a guide.

Then I need to select 3 more circles with widths of: 117.5mm (outer edge of my label, 16.7mm (inner edge of my label) and 8.7mm for the disk hub.  Once these are all selected as guides I lock the guides down so no more can be added. The template now looks as below.

Next I will need to decide on designs for my disc label and this will be discussed in a later blog post.