jpeg to phc conversion is typically searched by users that are looking for a way how to turn ordinary JPEG picture (perhaps a logo) to one of the many possible embroidery design tools.
What you need is a tool that offers so called digitizing function, i.e. tool that can be used to turn raster into vector and trace it to embroidery design. Works best for logos and other geometric shapes, but poorly for photographs.
Updated: November 7, 2023