[Insight-developers] itkHistogram.hxx - values equal to max bin are missed

Clarkson, Matt m.clarkson at ucl.ac.uk
Thu Aug 29 12:13:40 EDT 2013


Hi there,

I am upgrading from ITK 3.20 to 4.3.2 and noticed that in 4.3.2 a histogram with 64 bins (0-63), spanned by the image values 0-255 mapped the value 255 to bin 64, which was subsequently missed. This worked in 3.20, resolving to bin 63.

Comparing the code of itkHistogram.txx in 3.20, I see in method:
::GetIndex(const MeasurementVectorType & measurement,IndexType & index ) const

code that does:

    if (tempMeasurement >= m_Max[dim][end])
      {
      // one of measurement is below the minimum
      // its ok if we extend the bins to infinity.. not ok if we don't
      //Need to include the last endpoint in the last bin.
      if(!m_ClipBinsAtEnds || tempMeasurement ==  m_Max[dim][end])
        {
        index[dim] = (long) m_Size[dim]-1;
        continue;
        }

whereas in version 4.3.2 I see:






    if ( tempMeasurement >= m_Max[dim][end] )

      {

      // one of measurement is above the maximum

      // its ok if we extend the bins to infinity.. not ok if we don't

      if ( !m_ClipBinsAtEnds )

        {

        index[dim] = (IndexValueType)m_Size[dim] - 1;

        continue;


So, it looks to me like version 4.3.2 is missing the condition where if a value is exactly equal to the upper bound then it is included. Then I went to JIRA and found:
https://issues.itk.org/jira/browse/ITK-2266

which suggests that this was a bug at one point, but was fixed in 3.20.

So, did I miss a link somewhere? Can someone advise me please?
Has the spec changed such that the upper bound is no longer meant to be inclusive in version 4+?

Thanks

Matt


------------------------------------------------------
Matt Clarkson Ph.D.
CMIC Software Manager
Senior Research Associate
m.clarkson at ucl.ac.uk<mailto:m.clarkson at ucl.ac.uk>
Skype: drmattclarkson

Centre For Medical Image Computing
http://cmic.cs.ucl.ac.uk/staff/matt_clarkson/<http://cmic.cs.ucl.ac.uk/>
Tel: 020 7679 0257
Fax: 020 7679 0255
Room: 2.21 Malet Place Engineering Building

Dementia Research Centre
http://dementia.ion.ucl.ac.uk/
Fax: 020 7676 2066
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