まず、所定のサイズの空のcv :: Matを作成してみてください。そのMatのすべてのピクセルを繰り返して、どの値を取るべきかを決定します。ここで
あなたが記述されたものに似た何かをするいくつかのコードです:
cv::Mat makeImageFromPointCloud(pcl::PointCloud<pcl::PointXYZI>::Ptr cloud, std::string dimensionToRemove, float stepSize1, float stepSize2)
{
pcl::PointXYZI cloudMin, cloudMax;
pcl::getMinMax3D(*cloud, cloudMin, cloudMax);
std::string dimen1, dimen2;
float dimen1Max, dimen1Min, dimen2Min, dimen2Max;
if (dimensionToRemove == "x")
{
dimen1 = "y";
dimen2 = "z";
dimen1Min = cloudMin.y;
dimen1Max = cloudMax.y;
dimen2Min = cloudMin.z;
dimen2Max = cloudMax.z;
}
else if (dimensionToRemove == "y")
{
dimen1 = "x";
dimen2 = "z";
dimen1Min = cloudMin.x;
dimen1Max = cloudMax.x;
dimen2Min = cloudMin.z;
dimen2Max = cloudMax.z;
}
else if (dimensionToRemove == "z")
{
dimen1 = "x";
dimen2 = "y";
dimen1Min = cloudMin.x;
dimen1Max = cloudMax.x;
dimen2Min = cloudMin.y;
dimen2Max = cloudMax.y;
}
std::vector<std::vector<int>> pointCountGrid;
int maxPoints = 0;
std::vector<upcloud> grid;
for (float i = dimen1Min; i < dimen1Max; i += stepSize1)
{
pcl::PointCloud<pcl::PointXYZI>::Ptr slice = upcl::passThroughFilter1D(cloud, dimen1, i, i + stepSize1);
grid.push_back(slice);
std::vector<int> slicePointCount;
for (float j = dimen2Min; j < dimen2Max; j += stepSize2)
{
pcl::PointCloud<pcl::PointXYZI>::Ptr grid_cell = upcl::passThroughFilter1D(slice, dimen2, j, j + stepSize2);
int gridSize = grid_cell->size();
slicePointCount.push_back(gridSize);
if (gridSize > maxPoints)
{
maxPoints = gridSize;
}
}
pointCountGrid.push_back(slicePointCount);
}
cv::Mat mat(static_cast<int>(pointCountGrid.size()), static_cast<int>(pointCountGrid.at(0).size()), CV_8UC1);
mat = cv::Scalar(0);
for (int i = 0; i < mat.rows; ++i)
{
for (int j = 0; j < mat.cols; ++j)
{
int pointCount = pointCountGrid.at(i).at(j);
float percentOfMax = (pointCount + 0.0)/(maxPoints + 0.0);
int intensity = percentOfMax * 255;
mat.at<uchar>(i, j) = intensity;
}
}
return mat;
}