Image Guildelines
“A picture is worth a thousand words” and nowhere is that more true than the web. Good photographs, especially of people, give visitors a sense of familiarity and trust. Good informational graphics can express concepts or convey data effectively. In general, images warm up a page and help focus the reader’s attention.
Curators who will be involved in publishing images frequently should obtain Adobe Photoshop Elements image editing software (contact Information Systems to order it for your office). Use of other “cheap” image editing programs often results in poor quality and large file size.
Following guidelines apply to all images used on official EMU web pages:
- Strong, single images should be used, not a collage.
- A feeling of natural light and space should be present in the images.
- Images should be high-quality and incorporate people wherever possible. Do not use clip art or clip art-like illustrations!
- Images should follow the dimensions and format standards listed below.
Image Alternate Text
The Add Image dialog box in the CMS.
Entering alternate text for every image is the first step we can make in being accessible to visually impaired people. Alt. text also important because most search engines use this information to build search results. When inserting an image using the button on the Textile toolbar, there is a field for alternate text.
To help search engines, give your image files a name that directly corresponds to the picture. If it is a picture of a person, use their name. For example, john-paul-lederach.jpg
Image dimensions
The height and width for a picture comes from the image itself. Resize images in your image editor before attaching them. Make sure you resize proportionally so the image doesn’t look squashed.
Image formats
The easiest way for web content contributors to help keep page loading times short is through discriminate use of images. Two main image formats are used on the web: JPEG and PNG. Each is specially suited to a particular type of image.
The PNG format is best used for saving graphics and illustrations, especially those containing text. An 8-bit PNG reduces the number of colors (you choose the number of colors in the palette) and thus the file size. a 24-bit PNG has more colors but is generally much larger. Make the file size as small as you can without losing too much detail.
The JPEG format is best for photographs as it is very efficient at compressing natural looking images. JPEG images can be saved at varying levels of quality. Generally, a low quality level still provides acceptable use for display on the web. Using the Save for Web function in Photoshop, aim for a compression level of 30% and then increase it until there are no longer artifacts around faces and other important parts of the image.
To learn more about image formats, read Cleaner, Sharper GIF, JPEG, And PNG Images