Images are an essential ingredient for Web Site design. You want visitors to have an aesthetically pleasing experience. Properly preparing your images is necessary to enhance appearance of your web site. In Part I of this article I will explain:

When to use images for your web site. What image file formats should you use on Web.

When to use images for your web site - Navigation Graphical buttons can link to other pages or resources.

Image Maps – this is a graphic that contains several links on it. It has several "hot spots" or invisible buttons, you can click on. For example you could have a photograph of your family and put a hot spot on each person's face that links to that person's web site.

Logos and Trademarks – your business or organization's trademark are crucial for name recognition and branding.

Thumbnails – this is a small, "thumbnail-sized version of an image. When you click on it, you jump to another page with a larger version of same image. The visitor can see many different, small images on first page without having to wait for larger files of larger images to load.

What are different image file formats? Web graphics can be categorized into two file formats: bitmap and vector. Bitmap – these are composed of individual values for each color displayed. The larger dimensions of image, larger associated file size will be for same graphic. When viewed with magnification, a bitmap resembles a series of little squares, each of which has a color value that contributes to overall shape. Bitmaps have a very rough appearance when viewed closely but form images when viewed from a distance.

Bitmaps are best suited for photos, drop-shadow effects and soft, glowing or blurry edges.

Vector – these store information about image in mathematical instructions that are then interpreted and displayed.

Vector graphics are best suited for line art, shapes and illustrations.

Image File Formats Graphic file formats used on Web are GIF, JPEG and PNG

Graphics Interchange Format (GIF) GIF is a platform-independent file format that is limited to a display of 256 colors. GIF has been adopted by most developers because of its small file size.

professional image for your business means your web site design must be professional also.

Part one of this article discussed when to use images for your web site and what image file formats to use on Web (www.isitebuild.com/imageoptimization1). In this article (Part

2), we will discuss how to optimize your images for Web.

Image optimization is art of making your images suitable for Web. There is a large difference in preparing your graphics for print compared to Web. In print you have to have as much data as possible to get a good graphic. The main factors that influence display of graphics for Web, are size of file and screen display quality of graphic.

Factors Affecting Web Graphics

1. File Size When you design web pages you need to create a balance between visual appeal and page download time. If your page has too many images on it, it will take too long too load and visitors will not stay around to wait.

2. Cropping This means cutting out unwanted areas of your image. It decreases file size and helps visitors to focus on your image.

3. Anti-aliasing Jagged edges of an image can be prevented by anti-aliasing. This creates a blended edge around an image. Because of extra colors necessary to create blend,

file sizes of anti-aliased GIFs are a little larger. Use anti-aliased graphics in almost all cases, except when

creating very small type as graphics.

4. Bit Depth and Screen Resolution Bit depth refers to number of colors in an image or number of colors a computer system is capable of displaying. To calculate bit depth, one bit equals 2 colors, then multiply 2 times 2 to arrive at each higher bit depth. Quality and file

size decrease as bit-depth decreases.

New computers support thousands or millions of colors (32-bit), but many older color systems can only show up to 256 (8-bit) colors at a time. This reality imposes limits on size of files and number of colors that can be included in Web graphics.