How could I reduce the complexity of an image map?

Question

I'm using KImageMapEditor on Linux (Ubuntu) to create an image map. The shapes in the image are a little complex so I'm using the freehand tool to draw them. However, this is really the same as the polygon tool so the shapes have ended up with a lot of points, which has made the HTML pretty huge.

Does anyone know of a way to reduce the complexity of the shapes, like "smoothing out" the lines?

I should also mention the reason I want the shapes to be fairly accurate is because I'm intending to do something like this, where each shape is highlighted on mouseover: http://davidlynch.org/js/maphilight/docs/demo%5Fusa.html

Answer 1

Since users aren't going to click to the pixel, give them some leeway and create a "sloppy" map which roughly outlines each shape instead of clinging to the actual pixel outline.

This is in the same way as you don't expect a click on a link to fail just because you click on the background which shines through the text. You expect the bounding box of the text to act as the click-able area instead of the "black pixels".

Answer 2

Algorithm: Given three consecutive points, eliminate the middle point if the angle created is less than some tolerated error e. Polygonal path simplification with angle constraint