![]() As the number of people using this browser continues to decline, the PNG format is being used more frequently. For many years the adoption of PNGs (especially the use of the transparency) was held back because Internet Explorer 6 ignored the transparency. A PNG also offers better transparency features than a GIF, most significantly the support of alpha channels. This means it can be used quite effectively for simple graphics as well as continuous tone photographic images. The PNG format is closer to GIFs in that it offers lossless compression and comes in two categories: 8 bit and 24 bit. The PNG format has become increasingly popular on the Web in recent years because it incorporates many of the best features of JPEGs and GIFs. However, because photographic elements such as gradients and soft edges require a large number of colors to appear convincing, GIF images containing these elements look choppy and posterized. Unlike JPEGs, GIFs excel at reproducing sharp edges and solid areas of color. Logos, illustrations, and line drawings are well-suited to this format. ![]() This means that images with a limited number of colors can be reproduced without degradation. Instead, GIFs rely on a maximum of 256 colors to reduce the size of images. Unlike the JPEG format, GIFs do not use lossy compression. GIF is an acronym for Graphics Interchange Format. The GIF format was created by CompuServe. However, reproducing sharp edges and solid areas of color often requires a higher quality setting. The goal is to reduce file size as much as possible without creating distortion and artifacts.īecause JPEGs were designed to handle photographic images, they can significantly reduce the size of images containing gradients and soft edges, without producing noticeable degradation. A low-quality image discards more information, but produces a smaller file size. A high-quality image preserves more information and results in a larger file size. When you save a JPEG, you decide how much information you are willing to sacrifice by selecting a quality level. Specifically, it uses lossy compression, which means that it selectively discards information, to reduce the size of a file. ![]() Its sole purpose is to compress photographic images. The JPEG format was created by a committee named the Joint Photographic Experts Group. While an exhaustive description of how each of these formats compresses data is beyond the scope of this book, a general overview can help you avoid some common pitfalls. ![]() The three most common image formats on the Web are JPEG, GIF, and PNG. A visitor to your website still must download the 30k file which translates to slower loading time for the image (and possibly the page) and a potentially poor user experience, especially if they have low bandwidth. However, even though the image is visually smaller, the file size remains the same. You could resize this image in Dreamweaver by 50% and the result would be a thumbnail image displayed at 75 pixels by 75 pixels. For example, a JPEG image that is 150 pixels by 150 pixels might have a file size of 30k. Specifying the width and height of an image in the Property Inspector changes the display size of the image, but it does not resample the image the way a graphic processing application like Photoshop does. While it is possible to resize images with Dreamweaver, it’s generally not a good idea. ![]() However, before you learn to insert images, you will briefly learn about web graphics. Just as lists make content friendlier and more accessible, images help to give your visitors the rich, visual experience that they’ve come to expect on the Web. Images are an essential part of most web pages. For more Adobe Dreamweaver training options, visit AGI’s Dreamweaver Classes.Īdobe Dreamweaver Tutorial: Inserting images in Dreamweaver It is the third lesson in the Adobe Dreamweaver CC Digital Classroom book. This tutorial provides you with a foundation for working with the Adobe Dreamweaver workspace. What you’ll learn in this Dreamweaver Tutorial:
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