<div class="gmail_quote">On Wed, Nov 3, 2010 at 7:40 PM, Richard Beare <span dir="ltr"><<a href="mailto:richard.beare@gmail.com">richard.beare@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
That image isn't a "pure" binary one (at least plotting profiles<br>
across the edge suggests that there are other values), so there is<br>
probably some antialiasing going on around the edges. You could verify<br>
this by thresholding.<br>
<br>
You could do a greyscale erosion instead - it should look more natural.<br>
<br>
At the moment the values that are close to 255 are being left<br>
untouched, leaving the speckle.<br>
<div><div></div><div class="h5"></div></div></blockquote></div><br><div><meta http-equiv="content-type" content="text/html; charset=utf-8">Ah, I see it now. I thought (assumed) it was actually a binary image. Another case of "you know what happens when you assume...". Should the filter report an error (or at least a warning) if the input image is not binary?</div>