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images

In order to add photos and images on our website, we need to assess both the quality and load time of it. There are two main factors that determine the size in bytes of the graphic element to be inserted: its dimensions and the number of colors in it. Both contribute directly to its size and therefore inversely with the load time. Moreover, the storage form of graphic or image most widespread in the construction of Web pages is limited to files of type GIF or JPG.

The First, GIFs , are suitable for icons , logos, graphics ... with 256 colors and the ability to set transparent colors and animated graphics as the main features. Additionally we can define the image is interlaced which lets you view the image gradually as it is charged.

When you want to use a color palette higher than 256 colors you must use the format JPG . This format allows up to 16 million colors, thanks to the compression system is most suitable for photos or images with a variety of colors and details which are not as important as in the case of icons or logos. There is software that optimizes the file size by reducing the number of colors and dimensions of the image while maintaining its original quality.

However the end result of the display of the page depends on the browser and settings each user's computer.

If we publish a catalog of images, we recommend using a text index that links to the page containing the image. Another possibility is to use a small version of the images that serve as the index but the size of each should be as small as possible.

Some errors when publishing images vuala are:

  1. Use large images and reduce them in the editor and not do it with a photo editing program. By acting in this way the users visiting the website, get the big picture with the cost (time and money) is involved and then the browser, which reduces it. The correct solution is that before placing the image on the site, reduce it with a photo editing program and then insert it into our web page at actual size, without reducing it. In this way the user receives the image as we will see
  2. Unlike before, you normally use a small image placed on your website and is in vuala where it is enlarged. This practice, the expansion of a small image to a larger one, is recommended neither in vuala but also in a photo editing program because the image is distorted. The solution to this problem is to get a version of the image as large as possible and then reduce it.
  3. To make changes on the photos you can use the program XnView. This is a freeware program allows us to enlarge, reduce, crop .... on images of a very simple way. For more information on this program, check the documentation that exists for that purpose in the course of "web publishing"

 

Documentation related to the inclusion of "images" on a web page using vuala.

 

Accessibility

Provide a text equivalent for every non-text element (through the alternative text .) This includes: images, graphical representations of text, image maps, animations (eg animated GIFs), graphical buttons, sounds (played with or without user interaction), sound files, audio tracks of video, and video.

Computing service AU style guide


Universidad de Alicante
Carretera de San Vicente del Raspeig s/n
03690 San Vicente del Raspeig
Alicante (Spain)

Tel: (+34) 96 590 3400

Fax: (+34) 96 590 3464

For further information: informacio@ua.es, and for enquiries on this web server: webmaster@ua.es

Carretera San Vicente del Raspeig s/n - 03690 San Vicente del Raspeig - Alicante - Tel. 96 590 3400 - Fax 96 590 3464