Bitmap and Vector image formats
Digital images can be produced as either Bitmap or Vector format images. When producing digital images the image format they should be in should be carefully considered.
Bitmap images
A bitmap image is based on pixels: small squares each containing a colour. When built up they produce an image. Bitmaps are effective for conveying subtle blends of tone and colour. Photographs taken with digital cameras are built up with pixels and computer programmes such as Adobe Photoshop produce bitmap images. File formats such
as GIF, JPEG, and TIFF are bitmap images.
Bitmap images are based on resolution, often referred to as dots per inch (dpi). The higher the images dpi, the higher the image quality. This also produces a bigger computer file. However when a bitmap image is enlarged the small pixels become visible - this can be a problem when a bitmap image is scaled up on CCTV, magnifier or photocopier.
Vector images
A vector image is built up with shapes rather than small square pixels, therefore lines are smooth and colour is crisp. File formats such as Adobe Illustrator's .ai file and CorelDraw's .cdr are examples of vector file formats. Unlike bitmap images, vector files are not dependent on resolution so when these files are scaled up with CCTV or magnifiers, there is no loss of quality to the image. Therefore vector-based images are preferable for producing crisp and clear diagrams that are easy to scale.