SVGZ vs. PNG

As the number of mobile devices used for connecting to the internet increases, the need for quick downloading and displaying complex graphics also increases. Complex graphics typically consist of large machine-generated data sets, so in order to display these images in a timely fashion with limited bandwidth, compress graphical file formats play a big role.PNG and SVG are two ways to display compressed images on the Internet. Portable Network Graphics (PNG) is an extensible file format for portable, lossless, well-compressed storage of raster images. Scalable Vector Graphics (SVG) is a language that uses XML to create two-dimensional graphics. SVG files that have been gzip compressed are called SVGZ and typically result in files that are ten times smaller. SVGZ files work the same as SVG files but use less bandwidth and disk space. Which file format can make the most use of your disk space bandwidth?

For my poster, I want to show that in large files, SVGZ gives better compression that PNG. I will create graphic files consisting of m concentric polygons with n sides where each of the m polygons will be in a different colour m and n will varied from 3 to 35000 in intervals of log2(m-1). After the SVG test files have been created, they will be converted into both PNG and SVGZ format. The file sizes for each format will be denoted by

and the normalized file sizes will be denoted as :

The results will be summarized into three graphs :

For the first two graphs, the intersection point between P(m,n) and Z(m,n) signifies when the PNG file size is larger than the SVGZ, and therefore a switch in file formats is needed. These intersection points will be used to create the last graph, the curve will represent the points where both file formats gives about the same amount of compression and either format can be used. The upper section of the graph shows when SVGZ should be utilized and the lower section of the graph shows when it's best to use PNG.