Chapter 10: Working with Images

Overview

Advances in the graphics capability of personal computers, coupled with low-cost digital cameras , has resulted in a significant increase in the use of image-based applications. From photographs of employees being digitized and incorporated into personnel databases to photographs of automobile accidents with a digital camera being uploaded by insurance agents to the home office, we are witnessing a literal explosion in the use of image-based applications. Because local area networks (LANs) primarily support personal computer-based applications, it should come as no surprise that the transmission of images via LAN media is also increasing. In addition, the explosion in the growth of the World Wide Web has had a considerable effect on the transmission of images on both an inter- and intra-LAN basis.

For LANs connected to the Internet, the "surfing" of Web sites can considerably increase the flow of images on the corporate LAN. Even without connecting the corporate LAN to the Internet, the establishment of corporate Web server-based help desks can result in an increase in the transport of images. Although the use of images a few years ago was basically a curiosity , today they are essentially a necessity.

This chapter focuses attention on techniques to enhance the storage and transmission of images. To obtain an appreciation for the problems associated with the use of images, we will briefly review their storage requirements, as their transmission time is proportional to their storage requirements. Once this is accomplished, we will compare and contrast the effect of transmitting images upon LAN bandwidth to the use of text-based applications. Doing so will provide information that not only explains the bandwidth problems associated with transmitting images on a LAN but, in addition, provides a foundation for discussing techniques you can consider to minimize the effect of images on LAN bandwidth and server storage capacity. The preceding information will form a foundation for examining a variety of techniques that you can consider to enhance the use of images on a LAN while minimizing their effect on other network users.

In concluding this chapter, we focus attention on a very practical problem most organizations will eventually face if they have not already done so. That problem is the selection of an optimal Web server connection rate to the Internet. Because Web pages are graphic intensive and many Internet service providers (ISPs) now bill based upon the level of utilization of circuits used to connect subscribers to the Internet, we also examine the effect of image compression on both the line operating rate and potential cost of the Internet connection.