Trying to emulate the layout descisions made by the browser (note that there are many browser distributions and versions each doing it slightly differently) is neither anticipated by the browser developers nor a generally good design, since HTML never was supposed to give complete control of the final layout.

SVG is very easy to generate and you have much more accurate control of the layout. If you have to deal with browsers that doesn't understand it, you can use a server side tool to render a bitmap image from SVG.

Since it is an XML based standard, it is straight forward to create templates and use them much the same way you'd publish web pages. All you need to change is the content type.

Try taking a look at some SVG examples or the SVG specification.

Another obvious alternative to SVG is generating bitmap graphics straight away as suggested in other posts.