Do you know what RASTERS and VECTORS are? Well up until this week, I had never heard the terms - I think I might have previously heard of vectors but it had nothing to do with images and the words alone, made me think of dinosaurs... So, the subject initially was pretty muddy for me because I was unfamiliar with the terminology and I had no clue about "this new technology that I was in the midst of learning".
You probably could have heard it a mile away - I gave a sigh of relief when finally, the light bulb of understanding was bright and I got it! Below, I will quickly share with you my understanding of this subject. First let me give a few pointers about the differences between the two (2) types of images, so you can easily decide which will be appropriated for your next graphic image project:
 |
http://en.wikipedia.org/wiki/File:VectorBitmapExample.svg  |
VECTORS: This image type will give you the most flexibility. And if you need to make a lot of changes to your image before you finalize it, definitely choose this type. Also, if you are not sure what size you need, have no fear with vectors, they are scalable and can reach extremely large dimensions without becoming distorted (blurred, grainy, etc.). Vector files usually end with .SVG or .TSVG.
RASTERS: If you are working with photographs - you definitely want to use raster-based images as generally, a vector-based image as a photo does not work well. You will know you have raster images because these type files usually have file names ending with .JPG, .PNG, and GIF. These "Bitmap" files can be large and take up a significant amount of space.
Now, I will explain how each image is generated and I will also provide you with examples:
 |
http://en.wikipedia.org/wiki/File:Rgb-raster-image.svg Permission granted for reuse with Wikimedia Commons. |
A raster image is created by using tiny little dots called pixels. Each pixel is assigned a color value and this arrangement of the pixels reveals the detail of the image. This arrangement makes it a great choice for the subtlety that can be involved with detailed photos. However, it is also the reason why the image can lose detail and clarity when it is enlarged - as you are spreading the pixels over a larger area.
Adobe Photoshop is a raster-based program and it works beautifully with pictures. It also offers a lot of special effects. However, once you save your image, you will not have as much flexibility when it comes to editing say - just the background - to accomplish this, you might have to actually recreate your image. Only this time, make sure you use the features you desire while you are creating your image.
Vector images are a bit more complex, they are actually created using mathematical equations - but don't worry, you will not even know the math is taking place - it's all done behind the scenes. The equations define the points and shapes of the image and if the image is resized, the equations will be recalculated accordingly so there is not a loss of detail or quality. This is the reason why size is not an issue for these images. Adobe Illustrator is a vector-based program and is excellent to work with if the potential for a lot of editing exist or you need varying sizes of your image.
To try and give you a real-life visual of the differences between rasters and vectors, below I have provided an image of each:
 |
http://en.wikipedia.org/wiki/File:Phone.jpg  |
However the image below is a vector-based image of the original raster-based image discussed above. You can clearly see that the image below, has been enlarged and it appears that the the detail is even clearer than that of the original object.
 |
| http://en.wikipedia.org/wiki/File:Phone.svg |
Another plus to using vector-based files is the file size itself, because everything is calculated using mathematical equations instead of using pixels, vector-based file size is a lot smaller than those of raster-based.
However, both image types are very important as they each have different benefits and uses. And there is reliable software available for both types like the Adobe products I mentioned earlier.
I hope the information I've shared takes the intimidation out of your next digital image project and helps to make it a bit easier...
