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Multimedia on the Web: Multimedia and PowerPoint: Elsewhere on this site:
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Resources: Images from the web risk running afoul of copyright and fair use, and images from your own classroom may compromise your students. Here's a short list of image resources you can use without risk. The
tools: Good image manipulation programs are a dime a dozen. Here’s my short list, ranked by my preference (from good to less-than). For our purposes it matters little which you use (or something else not on this list) – you just have to be happy with it, and it has to do the short list of things we ask of it. This should include: resizing, color depth changes, format conversions, selecting and changing transparency color.
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Formats: For a complete discussion of image file formats, see "Image Formats" under "Images." The
rules: Here is a list of hints on how to make your Web page images smaller so they will load faster and impact bandwidth less: Ø Stick to business! Images are easy on which to go overboard. If it isn’t related specifically to the subject of the page or the navigation through the website, it’s probably just clutter and you shouldn’t be forcing someone to download it to see your site. Trash it! Ø Size to fit! Larger images make larger files (duh!). Some adjustment, of course, is inevitable, but if you know your image will occupy a 3” square corner of the screen, don’t save it as a 12” image and resize in FrontPage! Ø Don’t use images in the highest quality mode! If you’re printing pictures, you want high quality. In contrast, computer screens (and their users) are much more tolerant of low-quality images. Don’t use scanned pictures or digital photographs as-is. Decrease resolution – you can always “undo” in the software if the results hurt the image. Ø Count colors! The larger the color count, the more complex the image, and the larger the file size. If you’re starting from scratch with a banner or other GIF, don’t make the image needlessly complex by using a lot of colors and shading. If you’re converting or scanning an existing image, count! Paint Shop Pro will count colors, and will decrease color depth for you. Experiment - a JPEG will often look goofy in 16 colors, but will be fine in 256. Scanners and digital cameras save in millions of colors, and that is the JPEG format standard as well. However, if you decrease the color count before saving, it can greatly decrease file size, often with no discernable penalty to your image! In general . . . Remember – if (for example) resizing to fit reduces an image file from 54k to 5.4k, it will load ten times faster! |