PCXSLT18 translates PCX (black/white) to DXF. This program was written to handle huge CAD scanner files (unlimited size), but is also great for translating clip art files.
There are extensive methods to handle large files. Set the layer size then extract all layers or any single layer. Scan at high resolution then selectively eliminate scan lines to reduce file size. Pixel filters can be set to eliminate as much as you want. These features make it possible to extract pieces of large files for tracing and later combining.
