Bug in RLEImage::CleanUp() – myBuffer is itk::Image, but code uses size(), empty() and operator[]

[Joker-7-7]

Description

There is a bug in RLEImage<TPixel, VImageDimension, CounterType>::CleanUp():

itksnap/Logic/RLEImage/RLEImage.txx

Line 87 in 9709905

void RLEImage<TPixel, VImageDimension, CounterType>::CleanUp() const

The member myBuffer is defined as:

typedef typename itk::Image<RLLine, VImageDimension - 1> BufferType;
BufferType myBuffer;

However, the implementation of CleanUp() treats myBuffer as if it were a 2D std::vector:

assert(!myBuffer.empty());
if (this->GetLargestPossibleRegion().GetSize(0) == 0)
    return;

#pragma omp parallel for
for (CounterType z = 0; z < myBuffer.size(); z++)
    for (CounterType y = 0; y < myBuffer[0].size(); y++)
        CleanUpLine(myBuffer[z][y]);

itk::Image does not provide:

• empty()
• size()
• operator[]

This code cannot compile and appears inconsistent with BufferType.

It looks like an earlier version used std::vector<std::vector<RLLine>>, but later it was replaced with itk::Image<RLLine,...> while leaving the old loops in place.

Could you confirm the intended structure of myBuffer and whether this function needs refactoring?

Proposed fix

Below is a corrected version of CleanUp() using proper ITK image access and OpenMP-compatible iteration:

template< typename TPixel, unsigned int VImageDimension, typename CounterType >
void RLEImage<TPixel, VImageDimension, CounterType>::CleanUp() const
{
    if (!myBuffer) 
        return;

    if (this->GetLargestPossibleRegion().GetSize(0) == 0) 
        return;

    typedef typename BufferType::RegionType BufferRegionType;
    BufferRegionType region = myBuffer->GetBufferedRegion();

    itk::ImageRegionIterator<BufferType> it(myBuffer, region);
    for (it.GoToBegin(); !it.IsAtEnd(); ++it)
    {
        RLLine& line = it.Value();
        CleanUpLine(line);
    }
}

Notes

• This fix preserves the existing const qualifier on CleanUp() thanks to mutable myBuffer.

• The patch assumes that CleanUpLine processes each RLLine independently.

• The logic now correctly supports arbitrary (VImageDimension - 1) dimensions.

[skashtanoff]

Note:
It seems to be related to commit b2a537e. CleanUpLine was uncommented there.
Use this to reproduce:

git show b2a537e63 | grep "CleanUpLine" -B 10 -A 10