2 Fall/ Winter 2002 The Problem I often receive a Word document by e-mail that is several hundred kilobytes (KB), yet only com- prises one page with a small, embedded bitmap, such as a résumé photograph or a company logo. The larger the document size, the longer it takes Word to “repaint” it while editing or view- ing, the longer it takes to print, and the longer it takes to e-mail or download from a web site. Whereas I probably would not notice any appreciable delay with a 1-page document, I would notice the difference with a typi- cal proposal document of several tens of pages, each with an embedded graphic of some kind. For example, suppose you take a picture with a digital camera of a new employee to add to their résumé. A 1-megapixel camera produces a portrait bitmap image of, typically, 864 pixels by 1152 pixels. This results in a JPEG file of around 240 KB. Now, you insert this picture into a Word document—the employee’s résumé. The picture is initially very large, so you grab the corner of the picture and shrink it down to the required size, say, 1.5 inch- es wide on the page, and you might crop some unwanted areas off the picture. Happy with your results visually, you save the document. The doc- ument now only contains a small picture, right? Sorry, you’re wrong! You have not compressed the picture, merely squashed it. The file will be around 240 KB larger than before you inserted the picture. That probably takes a 1-page Word document up to around 300 KB—or around a minute of download time over the Internet on a 56K dial-up modem. Extrapolate those figures to a typ- ical proposal document and you can end up with some enormous file sizes, and corresponding long download and printing times. Large bitmaps also slow down editing, because it takes Word longer to repaint the screen when you scroll the document. “But,” I hear you say, “I want the highest quality for my printed documents!” Don’t we all, but we don’t need huge bitmaps to achieve it. In fact, printing a bitmap at a resolution of more than 150 to 200 pixels per inch (PPI) achieves no noticeable visual increase in quality. Even high-end laser printers, such as continued on page 3.◗ How to correctly set bitmap resolution t o minimize f ile size, maximize editing and printing speed, yet maintain quality Wordman’s Production Corner The PPI Perspective
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.