通过有效的色彩处理来缩短下载时间（外文文献翻译）.doc

Decreasing Download Time through Effective Color Management Kate S. Knight Several techniques make graphics smaller without losing image quality. Three prominent designers share their secrets. How do you create Web beautiful pages that download quickly? Its easy if you understand the constraints of Web color management. This article is a synthesis of interviews with three top Web designers: Craig Kosak, Art Director, Microsoft Developer Network; Nadja Vol Ochs, Interactive Media Designer, Microsoft Developer Relations Group; and Lynda Weinman, author of Designing Web Graphics (/dwg). Theyll show you how to choose the right file format, how to select colors that wont dither (interpreted and shown by the browser as a different color), and how to squeeze your file sizes down to the absolute minimum. Youll find out how to weigh image size and image quality against download speed. Why Color Management? Media for the Web requires color management just as traditional printing does. But the tools for color management on the Web are far less sophisticated than the same genre of tools available to print designers. Moving from the highly developed technology of print design to the more primitive tools of Web design can be difficult. Limited or not, these are the only tools available so far. As Lynda Weinman states, Web design has very specific constraints that it pays to understand. One of the constraints involves color management. Anyone who has spent any time on the Web knows that you spend a lot of time waiting for pages to appear. Why is downloading so time consuming? Most users of the Web are on machines with slow network connections and moderate memory. According to Nadja Vol Ochs, most users reach pages at 49 Kbps or 52 Kbps. The time required to download the site is a major concern for a designers potential clients. Large graphics files exacerbate the slow-download problem. Lynda estimates that, at 14.4, a 60KB file takes about a minute to download. Thats about 1 sec