/usr/include/vxl/contrib/mul/vpdfl/ is in libvxl1-dev 1.17.0.dfsg2-4.
This file is owned by root:root, with mode 0o755.
..
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_add_all_binary_loaders.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_all.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_axis_gaussian.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_axis_gaussian_builder.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_axis_gaussian_sampler.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_builder_base.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_calc_mean_var.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_gaussian.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_gaussian_builder.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_gaussian_kernel_pdf.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_gaussian_kernel_pdf_builder.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_gaussian_kernel_pdf_sampler.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_gaussian_sampler.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_kernel_pdf.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_kernel_pdf_builder.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_mixture.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_mixture_builder.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_mixture_sampler.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_pc_gaussian.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_pc_gaussian_builder.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_pc_gaussian_sampler.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_pdf_base.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_prob_chi2.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_resample.h
/usr/include/vxl/contrib/mul/vpdfl/vpdfl_sampler_base.h