Digital illustrators use programs that are based on raster or vector interpretation of data, and all of us who have worked with Adobe Photoshop and Adobe Illustrator have experienced how different the workings of the two programs can be. Illustrator tends to be used more by illustrators and graphic designers that tend to focus more on object making. Illustrator is referred to as “object oriented” software. Photoshop tends to be used more by illustrators, photographers and designers who lean more toward making pictures. Of course these assumptions are not absolute, and the developers of both Illustrator and Photoshop have blurred the lines between raster and vector as they have evolved. This comes from each program attempting to provide a totally functional software solution. For instance, Illustrator uses some raster display effects and offers the user an option to rasterize elements and to use raster painting effects. Alternatively, Photoshop offers Bezier pen tool functionality, the option to use vector masks, and to create and save outlines. So with the cross adaptation between raster and vector, these software programs offer illustrators new options that didn’t exist a few years ago. And on top of all this, software programs like InDesign allow the use of both raster and vector components in a single document. One thing that can help illustrators and graphic designers make the decision as to which direction to go is to consider the purpose for the illustration, i.e., the software choice is determined by how the image must function. In order to make that decision an understanding of properties of raster, vector, and vexel imaging is indispensable.
Vector software is object oriented, a collection of objects that always retain their integrity. Straight and curved lines, gradients, and shapes including letterforms are an expression of mathematical descriptions. The positions, scale, and display attributes of all objects are noted mathematically using algebraic equations. Altering objects within an image results in an alteration of the mathematical data. This form of image processing preserves the integrity of the objects themselves. Because of this, there is no image degradation as a result of changing any of the objects attributes. Even when an object, say a perfect circle, cannot be viewed properly on a monitor without some distortion, because monitors display in pixels (picture elements), the circle will exist as a perfect mathematical construct. And, with the right output device will appear so.
|Illustrator vector file viewed in outline mode. © 2000 Don Arday.|
|Illustrator vector file viewed in preview mode. © 2000 Don Arday.|
|Photoshop raster version enhanced by raster image operation editing. © 2000 Don Arday.|