Image Processing Reference
In-Depth Information
Figure 2.8
Optimum filter output for observations shown.
It is in fact the majority function that requires at least two of the input pixels to
be 1 for the output to be 1. In the binary case, this also corresponds to the median fil-
ter. This is the best filter that can be obtained within the three-point window and no
other function can give a smaller MAE for this window.
The optimally restored image is shown in Fig. 2.9 and has 14 pixels in error
compared to the ideal image
I
o
. Recall that the noisy image
I
n
had26pixelsiner-
ror.
The optimally restored image is still not completely fixed. In fact, a reduction
in error from 26 pixels to 14 might seem significant, but is far from perfect. It
should be noted that the restoration window is very simple and tests have shown
Figure 2.9
The optimally restored image (with a three-point window) is shown at the top right.
It has 14 pixels in error compared with 26 in the noisy image.
