Heatmapdotnet is a project mainly written in C#, it's free.
Heatmap generator for .Net
Implementation of a heatmap generation algorithm based on .Net. Moved in from codeplex.
The heat is caclulated based on number of 'hits'. Every hit is represented on an x,y coordinate in an image, it is divided into 2 arrays of Xs and Ys out of performance considerations. Usage is simple:
Image im = new Bitmap("TestImage/Jenna.jpg");
float[] px = new float[]{
41,
72,
73,
73,
73,
73,
73
};
float[] py = new float[]{
41,
72,
73,
73,
73,
73,
73
};
Image canvas = HeatMap.NET.HeatMap.GenerateHeatMap(im, px, py);
canvas.Save("Jenna.Heated.Jpg", ImageFormat.Jpeg);