Cross Media Color Control and Design
What a different world this would be without painting, engraving, photography, illustration and halftones. But effective graphic communications is not merely the result of type and images: it is the juxtaposition of the two in a way that communicates a message that would otherwise not be possible if the elements were presented independently of one another. With hypermedia, a new interactive aspect is added to this process of arriving at a profound and meaningful presentation of information. There are many ways of capturing images in the electronic publishing process: scanning of conventional photography or original (mechanical) art; digital photography; desktop images created in pixel-based, "paint" or vector-based "drawing" programs; and use of CD-based or online photo libraries, to name a few. Whatever method is used to generate or capture images, below are some critical technical issues to consider.
Printing requires the highest resolution of all media output options. Line art used for a printed piece should be scanned at 1,200 dpi. For optimum quality of photographic images, it is critical to determine the printed halftone line screen before you capture the image. (The type of paper used on the press determines the halftone line screen value.) The resolution for optimum reproduction of detail typically is twice the halftone line screen. When using an electronic image for print media, use the following formula: optimum image resolution in dpi = 2 x lpi (dpi = dots per inch and lpi = lines per inch).
Once an image is acquired and archived at a resolution sufficient for printing, the same image can be resampled, or downsampled, at a resolution appropriate for interactive display on a computer monitor (usually 72 or 96 pixels per inch).
TIP: Remember that image resolution and image size are inversely proportional. This means that increasing the dimensions of an image on a page effectively reduces image resolution. While minor increases in the scale of an image may not be noticeable to the viewer either on the printed page or the computer monitor, increases of 25 percent or more are excessive and can degrade image quality.