Web Page Design
Laboratory Assignment # 9
1. The goal of the first exercise is to get caught up on late laboratory assignments. In the event that you are all caught up, you should go on to Exercise 2 and explore WWW images at a deeper level.
2. The purpose of this exercise is to examine two kinds of Web graphics (photographs & simple flat-color drawings) displayed as three file types (GIF, JPG, and PNG) and observe the resulting file sizes and image compression artifacts. Please use Graphics Converter to process the images and measure the image compression ratios.
2.1 Select a photograph from the WWW or your instructor's UWP.Scenes folder and scale it to about 4" x 5" (300 x 400 pixels). Save the image to your Zip disk in the following five formats:
2.1.1 Optimized, Interlaced GIF.89a
2.1.2 Progressive JPEG 6.0 with "Highest Quality" 
2.1.3 Progressive JPEG 6.0 with "Normal Quality" 
2.1.4 Progressive JPEG 6.0 with "Low Quality" 
2.1.5 Interlaced Adam7 PNG format with "Automatic" compression
2.2 Use Graphics Converter to reopen each of the graphics files saved in 2.1 and enter the following data in an HTML Table with column headings: "File Type", "Memory", "File Length", and "Compression Ratio".
2.3 Repeat parts 2.1 and 2.2 with a line drawing or flat-color logo with no more than three or four colors.
2.4 Embed two of the images generated above that show the following image compression artifacts:
2.4.1 Blurry edges or shadows caused by JPEG compression
2.4.2 Dithering of colors due to 256-color limitation of GIF compression
2.5 Save your work to your folder on CS220.Projects.
Revised March 13, 2001