Animated GIFs

Source: Wikipedia: Gif

What is a GIF? An animated GIF is typically a small image that can be used on a website to create basic animation effects.

The History of GIF

The Graphics Interchange Format (GIF) file was originally created in 1987 by CompuServe (GIF87a). It has become one of the most popular image file formats on the internet because of the fact that it is supported in most internet browsers. The result is that it has become one of the most popular image file formats on the internet, together with other popular well known formats such asJPEG and PNG.

The particularlity of GIF is that the images stored in the GIF format are limited to 256 colours so they are traditionally used in logos and simple graphics. The other formats, JPEG which works well with sharp colour contrasts. This type of colour is often be found when text is placed on a solid colour background. JPEG will try and smudge any hard edged that it finds when compressing the image.

The GIF specification was realised more in 1989 (GIF89a) to add animation capabilities as well as other features. This capability of storing multiple images within the same file, with their own 256 colour pallete displayed additionally a flag to determine the delay between image frames. Simple animations which are only 10 frames, at 20KB each, will create a file about 200KB in size. This is why most GIF animations tend to remain fairly small and basic, using as few colours as possible.

What are Distractions?

Typically animated GIF features are used on websites to create what is known as distractions. This effect is based on the fact that the human eye notices changing elements by the use of the peripheral vision. These are then recorded in the brain and compared with later viewed images. To illustrate this think of when a website wants to highlight a new feature, sometimes the designer may use a small "new" icon next to that feature. The icon is animated in some way by the use of rapidly changing background colour also known as flashing. (flashing).

Sometimes animations are too distracting for visitors especially with visitors who suffer with certain cognitive or learning disabilities. The repetitive flashing of text and graphics can make it impossible to read the main body of text.

Due to this unfortunate fact, some browsers allow visitors to stop them with the such as Firefox, by using the [esc] key. However not all browsers have this feature, and many people do not even know it even exists. This makes it quite common for visitors to leave a website if they find that trying to read the text is too difficult rather than adjusting it!

What about text in images?

Sometimes website authors will use an animated GIF to show text based information. Included with this there should be a text equivalent for visitors who are unable to view the images, for example search engine spiders and visitors who use screen readers. The text based equivalent should be provided though the alt or longdesc attributes found on the images, unless such a description does not provide any value to the document.

It should be kept in mind that text found within images may still be inaccessible to some visitors who do not use assistive technologies that provide access to the text equivalent. For example, if the text is too small, as browsers do not normally resize images when the user changes the text size. Also if the text is involved in the animation, some visitors will be unable to read it, as the movement might be distracting, or even the amount of time it is displayed might not be long enough to read.

What are Banners?

Websites have often used animated GIF's in website banners, as these capture visitor's attention and frequently cause the visitors to view the banner before the main content on the page. This advertising technique is done to increase the time spent on the sale, increase of sales and make the website more interactive and attractive.

Due to the constant viewing of so many banners the effectiveness of them is declining. The constant bombarding of basic animations and bright, high contrast colours, to which some frequent internet users have developed a phenomenon called banner blindness. This is where banners and banner-like elements on the page are simply ignored, or overlooked by the frequent internet visitor. In their place the text based adverts are becoming more commonplace, as these are small inoffensive blocks of text which are related (relevant) to the current page.

GIF benefits

Although, despite the issues listed above, animated GIF's are still useful as a simple image to explain a complex subject. Don't forget "a picture is worth a thousand words".

A alternatives can be used and they are the use of Flash animations. Usually these files can be much smaller and allow an interactive element to the animation. They can allow the visitor to start the animation when it is convenient for them, without it looping or causing a distraction when they are not using it. Giving this control to the website visitor can be particularly useful for professional website authors, as they keep to the standards set by the Web Content Accessibility Guidelines (WAI), which states that websites should avoid causing the screen to flicker.