How do I convert a file from .png to .dwg?
You can use free software to convert the linework to dwg file but even then it will not be clean drawing. You will have to redraw and scale the converted drawing to obtain exact dimensions and details. So best practice that I experienced is to attach the image in dwg file as a reference and then scale it. after that start tracing in AutoCAD.
I should also mention that we recently release rastertovector.com which allows you to convert raster images to SVG or DXF online for free.
This is a useful service for converting simple illustrations, logos, and other similar types of images to vector.
However, it’s not suitable for CAD/CNC purposes. For that, you should stick with desktop software such as Scan2CAD.