Processing: Creative Coding and Computational Art

eally shines. And remember, as you progress in Processing, you have the freedom and
flexibility to utilize Java classes such as BufferedImage, or even work in pure Java in the
Processing environment.
Graphic formats
Those of you with lots of computer graphics application experience can probably skim this
section. I do cover a little of the inner workings of both raster and vector graphics, which
might be new or of interest, however. In computer graphics, graphic image types are generally
broken down into two basic categories: raster graphics and vector graphics. Raster
graphics are usually continuous tone images, like photographs, that are not delineated
into precise shapes with smooth edges, but are built up as a series of pixels, like a painting.
The pixels blend together to form the illusion of a single image. The BufferedImage class
is a structure designed to handle raster graphics. Vector graphics are usually simpler
images, in terms of number of colors and detail. They have distinct parts, each delineated
with a concise edge. While raster graphics are a matrix of the actual pixels displayed on the
screen (or an approximation), vector graphics are mathematically described shapes, with
color fills, strokes, and other rendering attributes. Vector graphics can require much less
memory compared to raster graphics, as they represent the plots of mathematical expressions.
Since the computer is really a glorified calculator, it grooves on equations, but having
to keep track of millions of pixels in real time is more demanding. Ultimately though,
in the rendering process to the screen, eventually everything must be converted to screen
pixels. However, before the screen rendering, vector graphics are able to be stored as simple
expressions, rather than large arrays of RGBA color values, as with raster graphics.
Raster and vector graphics each have their strengths and weaknesses, and are generally
utilized for different purposes.
Raster graphics
COMPUTER GRAPHICS, THE FUN, EASY WAY
Raster graphics are typically utilized for photographic or other highly detailed continuous
tone images, where edges are not distinct and there is a large variation in color or value.
Common raster graphic image file formats include TIF, BMP, and JPG. Raster formats also
generally utilize some compression algorithms to ease their memory storage requirements.
Compression can be lossy, in which the image quality is actually degraded with
compression, like in JPG; or lossless, with no image loss, as in LZW compression, used commonly
with the TIF file format. Raster images have variable resolution, meaning that you
can specify how many dots of image information you want to pack into each inch. The
more dots per inch (dpi), the finer the image detail or resolution, but also the higher the
memory requirements. Monitor screen resolution is 72 dpi (Mac) and 96 dpi (Windows).
That means that it is only possible to see 72 dpi on the screen on a Mac; any higher will not
improve the quality of the screen image. So why would you want more resolution if you
can’t see it? Well, if you are only working on the Web, then you don’t need any additional
resolution—you’re done (assuming the image is the size you want it). However, if you ever
need to print your images, then you need more resolution; how much more is dependent
upon how you’re going to print. Offset printers that print magazines, posters, this book,
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