A longstanding client asked me to help him convert a pixel based logo he design to vector based format. Converting this pixel based logo was difficult because of the heavy use of gradation and texture. My solution was to use defuse dither in Photoshop and then import that into Illustrator for auto-trace. This gave me vector gradation with ought having to use a stylized bitmap halftone.
Original Pixel (Raster) logo designed by Michael Owen