Optimize Images with Large Areas of Solid Color Using the GIF Format
Part of the HTML5 & CSS3 For Dummies Cheat Sheet
When optimizing graphics that have text overlaid on a photorealistic image, you need to create separate slices for the areas of the image that are photorealistic as well as create additional slices for the areas of the image that contain text. Export the areas containing text using the GIF format, and export the photo-realistic areas of the image using the JPEG format. Here are some tips to help you out:
For high quality JPEG images, use a quality setting of 70 when exporting. For smaller JPEG images, you can get by with a quality setting of 50.
If you're creating a photo gallery for a product, or for a photographer, export the images in the JPEG format with a quality setting of 80.
When compressing images using the JPEG format, pay careful attention to the edges of objects in the image. When you begin to see pixels, or the edges lack definition, you've compressed the image too far.
When exporting images using the GIF file format, use the least number of colors that yields a crisp image and you'll have a fast loading image.
When you resample images for websites, the maximum resolution you need is 72 pixels per inch.
Websites with no video are becoming rarer. Video is everywhere on the Internet: it's used for entertainment, in ads, and to promote rock stars and other artists. When video is well done, it's a thing of beauty. Here are some things you need to consider when adding video to a web page:
Video takes up lots of bandwidth. If the bandwidth for a website is exceeded, the charge can be rather costly. Instead of hosting video on a website, upload it to YouTube, and then embed the video in a webpage or blog.
Don't violate copyright laws. Don't copy video from other web sites, or other people's YouTube videos and use them on your website.
Check the license: If you do use a video from a supplier or manufacturer on a commercial website, make sure you are covered by the supplier or manufacturer's license.
Use a high quality camcorder to record video: No, an iPhone is not a high quality camcorder. If you encode poor quality video for the web, you get poor quality video. Remember the old axiom: Garbage in, garbage out.
Make sure the website viewers have the necessary plug-ins to view the video.
If you create HTML5 pages with video, make sure the intended audience for the site uses HTML5-compliant browsers.
Don't use transitions when you edit multiple video clips to create a video for the web. Video transitions look great on HD video, but don't look good when you encode a video for the web.