Feature Preservation using Resistive Fuses

When applied to an image, a resistive grid has the effect of smoothing out noise from the image. However, it also has the effect of smoothing out features, such as object boundaries. An effective system needs to be intelligent enough to detect these boundaries and prevent the smoothing operation from destroying them. One simple way of doing this is to replace the resistances between nodes by resistive fuses. A resistive fuse acts just like a resistor until the voltage across it reaches a certain threshold. It then cuts off, with the current through it dropping to zero. If the voltage across the fuse drops back below the threshold then it begins conducting again. The characteristic of an ideal resistive fuse is shown in Figure 3.4.

Figure 3.4: Ideal resistive fuse characteristic