Chapter Four. Preparing Raster Images

Whether you acquire an image from a scanner, a digital camera, a royalty-free CD with 1,000,000 images, or a stock photography vendor, it's made out of pixels. Pixel is shorthand for picture element, the smallest unit of information in a digitized image. Even though pictures on your monitor look like smooth transitions of color, zoom in sufficiently and you'll see all the little square pixels that actually make up the image (Figure 4.1).

Figure 4.1. Images are made of pixels. Think of them as little-bitty mosaic tiles.