What the difference between bitmap images vector artwork?

KeyImagery supports the uploading of two very different file types called bitmap and vector, so what is a bitmap image and what is a vector image exactly? This is a common question that most people probably don’t know the answer to, but we’ve created this small article to help simplify the answer

Pretty much all static digital image files can be categorised into two distinct file types, bitmap-based and vector-based files. These two types differ in the way the image was created and how the computer analyses and uses their file data.

Bitmap Images

This is the most common file format that digital cameras and photo editing programmes produce and handle. File names for bitmap-based images usually consist of a file extensions such as *.JPG, *.PSD, *GIF, *.TIF, or *.BMP. Almost all digital cameras produce bitmap files that are in the JPEG (*.JPG) file format so if you are taking digital photos to upload to KeyImagery, your files are already in the format we need!

PLEASE NOTE: KeyImagery accepts bitmap files in the JPEG format only.

Each bitmap-based image is made up of hundreds, thousands or maybe millions of tiny pixels (squares) of colour that are mapped into a grid. The size of the grid is based on the image's resolution. For example, a bitmap-based image of 1 inch x 1 inch with a 600 dpi resolution would be defined by a grid of 600 x 600 pixels. With that said, a bitmap-based image is essentially a mosaic of tiny square pixels with each pixel being a specific colour value. When all of these pixels are put together in an arranged manner, they form the photographic images you can see on a computer screen.

Bitmap-based files are suitable for digital photos or photo-realistic images that require complex colour variations. The downside of a bitmap image is they are not easily enlarged because each image is made up of small pixels of colour. If a bitmap image is enlarged it loses its sharpness and some of the areas within the image would appear to be jagged and ‘pixelated’.

Vector Images

Vector-based images generally contain well-defined elements such as curves and shapes filled with various colours and outlined with strokes. File names for vector-based images usually consist of extensions such as *.EPS, *.AI, *CDR, or *.DWG.

PLEASE NOTE: KeyImagery accepts vector files in the EPS and AI  formats only. Your vector AI or EPS files can also be compressed in a ZIP file along with a high resolution JPEG which may be of use to some media purchasers.

Elements contained within a vector-based image file can either be pure graphics, typefaces or mathematical shapes. Each element is defined mathematically by the computer, so for example, if a vector-based image contains a red dot, then information such as the location of the circle's centre point, the length of its radius, and the colour red would be the essential information for this image file.

Vector-based files are suitable for illustrations that require precise measurements or need to be easily scalable (which they can be due to their mathematical nature). In saying that, the vector-based file format has one major drawback. It is not good for displaying photo-realistic images such as a photograph because images of this type generally do not contain well-defined shapes and curves.

Summary

Bitmap-based image files take up a lot of computer hard disk space for file storage than vector-based files. The former contains all information for every single pixel of the image while the latter contains only the defining mathematical formulas for each element within the image. They do not rely on mathematical formulas to define their various elements.

Published: 09/12/2007 12:10 PM | 279 View(s)