[common] pcl::getMinMax3d() support for pcl::PointXY

[sibi-venti]

Describe the bug

i cannot create pcl::segmentation with pcl::PointXY , it have a default way to convert to Eigen vector 4 map
Context

What are you trying to accomplish? Providing context helps us come up with a solution that is most useful in the real world

Expected behavior

it should be able to give you min max of x y points and 0 for z and w

Current Behavior

What happens instead of the expected behavior?
compilation issue
To Reproduce

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Screenshots/Code snippets

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• code snippets: syntax for code with correct language highlights

Your Environment (please complete the following information):

• OS: [e.g. Ubuntu 16.04]
• Compiler: [:eg GCC 8.1]
• PCL Version [e.g. 1.10, HEAD]

Possible Solution

//////////////////////////////////////////////////////////////////////////
template <typename PointT> void
pcl::MaximumLikelihoodSampleConsensus<PointT>::getMinMax (
    const PointCloudConstPtr &cloud, 
    const IndicesPtr &indices,
    Eigen::Vector4f &min_p, 
    Eigen::Vector4f &max_p) const
{
  min_p.setConstant (std::numeric_limits<float>::max());
  max_p.setConstant (std::numeric_limits<float>::lowest());
  min_p[3] = max_p[3] = 0;

  for (std::size_t i = 0; i < indices->size (); ++i)
  {
    if ((*cloud)[(*indices)[i]].x < min_p[0]) min_p[0] = (*cloud)[(*indices)[i]].x;
    if ((*cloud)[(*indices)[i]].y < min_p[1]) min_p[1] = (*cloud)[(*indices)[i]].y;
    if ((*cloud)[(*indices)[i]].z < min_p[2]) min_p[2] = (*cloud)[(*indices)[i]].z;

    if ((*cloud)[(*indices)[i]].x > max_p[0]) max_p[0] = (*cloud)[(*indices)[i]].x;
    if ((*cloud)[(*indices)[i]].y > max_p[1]) max_p[1] = (*cloud)[(*indices)[i]].y;
    if ((*cloud)[(*indices)[i]].z > max_p[2]) max_p[2] = (*cloud)[(*indices)[i]].z;
  }
}

you can make this global common i cannot use it outside this class

all min max does not support the PointXY

Not obligatory, but suggest a fix/reason for the bug. Feel free to create a PR if you feel comfortable.

Additional context

Add any other context about the problem here.

[larshg]

@sibi-venti there already is a getMinMax3D or getMinMax3D in common that is templated on the pointtype.

That should suffice?

[larshg]

Oops, they might not work on PointXY - misread it the first time.

[mvieth]

@sibi-venti There is some information missing in your problem description. Which class are you trying to use with pcl::PointXY? You mention pcl::segmentation, but which class exactly? Please show your code so we can reproduce the error, and ideally also post the compiler output (the complete error message).

[the-code-samurai-97]

@mvieth pcl::segmentation

MODEL : SAC_MODEL_LINE
METHOD: SAC_MLESAC

[mvieth]

@mvieth pcl::segmentation

MODEL : SAC_MODEL_LINE METHOD: SAC_MLESAC

@the-code-samurai-97 Do you mean like this or what?

#define PCL_NO_PRECOMPILE
#include <pcl/segmentation/sac_segmentation.h>
...
  pcl::ModelCoefficients::Ptr coefficients (new pcl::ModelCoefficients);
  pcl::PointIndices::Ptr inliers (new pcl::PointIndices);
  
  auto cloud_xy = pcl::make_shared<pcl::PointCloud<pcl::PointXY>>();
  cloud_xy->emplace_back(1.0, 2.0);
  cloud_xy->emplace_back(2.0, 4.0);
  cloud_xy->emplace_back(3.0, 6.0);

  pcl::SACSegmentation<pcl::PointXY> seg();
  seg.setModelType (pcl::SACMODEL_LINE);
  seg.setMethodType (pcl::SAC_MLESAC);
  seg.setInputCloud (cloud_xy);
  seg.segment (*inliers, *coefficients);

It is really unclear what you are trying to do, please show your code!
And please describe what you want to do in general! Do you have a 2D point cloud and want to apply the MLESAC algorithm to find a line in the point cloud? Or something else?