<meta http-equiv="content-type" content="text/html; charset=utf-8"><div class="gmail_quote">On Sat, Sep 17, 2011 at 5:28 AM, 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;">Your best hope is if your application allows you to use a sliding<br>
window approach - i.e you want to make use of histograms for regions<br>
centred at every (or almost every) voxel. These work by updating a<br>
histogram, rather than creating it from scratch every time. Some of<br>
the review code uses this for various types of filtering, although it<br>
doesn't use the histogram infrastructure. Check the<br>
*MovingHistogramImage* filters. I guess you could look at adapting the<br>
same approach to the ITK histogram. Of course, if you only want to use<br>
8 bit images then you're best off with simple 256 entry tables because<br>
everything will be much faster.</blockquote><div><br></div><div>Hi Richard,</div><div><br></div><div>I didn't see any tests or examples of MovingHistogramImageFilter, so I started putting one together:</div><meta http-equiv="content-type" content="text/html; charset=utf-8"><a href="http://www.itk.org/Wiki/ITK/Examples/Broken/Statistics/MovingHistogramImageFilter">http://www.itk.org/Wiki/ITK/Examples/Broken/Statistics/MovingHistogramImageFilter</a><br clear="all">
<br></div><div class="gmail_quote">The two main things I am missing are:</div><div class="gmail_quote"><br></div><div class="gmail_quote">1) Is there an interface to tell which pixel the filter's kernel is current centered on? That is, if I want to store the histogram for the region around every pixel in the image, how would I know which pixel the current histogram corresponds to?</div>
<div class="gmail_quote"><br></div><div class="gmail_quote">2) (very related to 1) How do I tell when the filter has moved the kernel (i.e. when should the current histogram should be saved for the current pixel and a new one started for the next pixel)?</div>
<div class="gmail_quote"><br></div><div class="gmail_quote">Thanks,</div><div class="gmail_quote"><br><div>David </div></div>