Page 19 - Demo

Project 1: Composite Movie Ad 29STAGE 1 / Compositing Images and ArtworkThere are two primary types of digital artwork: vector graphics and raster images. %u2022 Vector graphics are made up of mathematical descriptions of lines and shapes. Vector graphics are resolution independent; they can be freely enlarged or reduced, and they are automatically output at the resolution of the device being used to print them. The shapes you create in drawing applications such as Adobe Illustrator are typically vector graphics. %u2022 Raster images, such as photographs, are made up of a grid of individual pixels (rasters or bits) in rows and columns (called a bitmap). Raster files are resolution dependent; their resolution is fixed, and is determined when you capture or create the file. You can typically reduce raster images, but you cannot significantly enlarge them without losing image quality. %u2013 Line art (also called a bitmap image) is actually a type of raster image that is made up entirely of 100% solid areas. The pixels in a line-art image have only two options: they can be all black (on) or have no color (off). Pen-and-ink drawings are an example of line art. Photoshop is what some people call a %u201cpaint%u201d program %u2014 it is primarily used to create and manipulate pixel-based, or raster, images. Raster-image quality depends directly on the resolution at which the file is created. When you create files in Photoshop, you need to understand the resolution requirements from the very beginning of the process. Pixels per inch (ppi) is the number of pixels in one horizontal or vertical inch of a digital raster file. As a general rule, commercial print jobs require 240%u2013300 pixels per inch at the final output size to achieve good image quality in the printed piece. Some digital media, such as desktop web browsers, typically use much lower resolution (commonly 72 ppi), although monitors and mobile devices with HD display capabilities support higher-resolution images. It is important to realize that you cannot significantly increase image resolution once a raster image has been created or captured. When you create files that will be used for both print and digital media %u2014 as you will for this project %u2014 you should start with the higher resolution, and then reduce it after the composition is complete.The same raster image is reproduced here at 72 ppi (left) and 300 ppi (right). Notice the obvious degradation in quality when the resolution is set to 72 ppi.Note:Why is this information important? The ad you%u2019re building in this project will be placed in print magazines, so you have to build the new file with the appropriate settings for commercial printing. When the composition is finished, you will convert it to a resolution and format that is appropriate for digital media display.