Difference Between Bitmap And Vector
Bitmap images are also called raster images and they are resolution dependent. A higher resolution for example has 300 dots per inch dpi and the standard for images on your computer will be 72 dpi. The whole image is comprised of dots on the screen or page. There is no problem with the quality you get, if you know the size you want to end up with. Where you will run into difficulty is if you change your mind and want to enlarge a photo to twice the original size. You will be bound to run into the problem of jaggies. Edges that were nice and smooth looking now have stair step lines instead. From the .BMP, .JPG and .PNG there are a load of bitmap file types.
Vectors on the other hand are mathematical descriptions of lines, shapes, angles, and colours telling the computer how to display on the computer screen. They are infinitely scalable, whether you are reducing in size or increasing in size. No jaggies in these images. You will get sharp edges and high precision from vector graphics. The files will be .AI or .SVG type files. SVG stands for Scalable Vector Graphic. It is also possible to output .EPS for vectors.
Usage of the two types of graphic
Photographs will always be bitmaps and you will be turning to Photoshop, Acorn, Pixelmator and other bitmap editors. Web sites have a lot of bitmap images on them although with HTML 5 we may see more vector images because vectors will be more efficient and give faster loading pages. If you know the size you want for a bitmap then you will have an image that is good for the job in hand.
CAD - Computer Aided Design will require precision, that is the reason why architects use vector programs to design building. These specialist programs will also work in three dimensions for architects. It is also possible to print from these applications and the end result will be the large blueprints for buildings, for instance. Sign writers use 2D vector programs to cut letters in vinyl cutting machines. A sign guy may also print small letters onto sheets vinyl to save the work involved in cutting letters and removing the background.
Applications or Programs to use
For the manipulation of bitmaps the large gorilla in the room is Photoshop by Adobe, with a price to match. There are so many other bitmap program possibilities, ranging from free, open source to intermediate prices. Gimp is a free one. Pixelmator and Acorn are cheap to buy. Photoshop Elements is a cut down version of the big program that will be good for most people.
For the creation of high art, artistic graphics, a favourite is Corel Painter. This is for an artist that would like a more painterly experience with the computer. There would be tools and brushes that are metaphors for how an artist would work with physical tools and media. Another program of this type would be ArtRage, it is cheaper and has many of the features found in Painter.