Paint Shop Pro - About web graphics generally

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This is not a course. It is a...

Tip Sheet

File formats

An important consideration when designing Web pages is to keep the files small in size to facilitate quick downloading. For this reason, we use compressed image formats in Web graphics. The most common compressed image formats are JPEG (pronounced Jay Peg) and GIF (pronounced Jiff or as in gift). After creating or editing an image you should save it in one of these formats.

JPEG and GIF file formats will enable delivery (over the telephone line) of maximum quality pictures at minimum size, and therefore maximum speed (and minimum telephone costs).

JPEG

JPEG stands for Joint Photographic Experts Group. As the name suggests this is the best format for displaying photographs and other images with variable shading.

Variable shading is the term used to describe the varying degree of colour tints commonly found in photographs.

JPEG images are capable of displaying 24 bit colour, or 16.7 million colours. JPEG images can be further compressed, but quality deteriorates as compression is maximised. It is best to not further compress JPG graphics. If you want a smaller file size, try reducing the size (width and height) of the image.

GIF

GIF was developed by CompuServe and stands for Graphic Interface Format. This format can display images of 256 colours or less and is used primarily for graphic content with sharply defined colours, for example, logos. It is also used for line sketches.

An important feature of GIF is its unique transparency utility. You can specify that any colour in a GIF image is transparent. For example you may have created a logo and would like it to appear without any surrounding colour on the web document. You will then set the image’s background colour to be transparent. This feature is widely used in the World Wide Web. For example, the image to the bottom left does not have a transparent background and the image to the bottom right does have a transparent background.

An animated GIF is several GIF images composed into a single image which, when viewed, appears to be animated. Software like GifAnimator (downloadable at http://www.webutilities.com/ga .) is used to create animated GIFs.

Where to find graphics

Graphics are freely available on the World Wide Web. However, this in no way means that all graphics on the Web may be used at will. Only the graphics at sites offering free clipart are allowed to be used without permission. Use a search engine and do a search on "free clipart". You will see that there are many such sites. Here are just a few examples:

Animation Factory algebra_md_wht.gif (6195 bytes)

Absolutely Free Clipart (click on Clipart) sm_CDROM.gif (3072 bytes)

A1 All Free Clipart purponWood.gif (3116 bytes)

Most photographs on other Web pages are subject to the usual international copyright laws. Since you will be publishing your Web site in a public forum (the Web) you cannot just take a photograph and use it. However, if you write to the owner of the site and ask permission, you are most likely to be given permission to use the photograph in your site. In this case you would acknowledge this ownership by indicating the Web site where you found the graphic and that you have permission to use it.

To capture an image from a Web page

Right-Click on the image

Choose Save Image As

and save it to a folder of your choice. If you want to use it in a Web page, it is advisable to save it to the same folder.