Changed Host Display Information (HDI) may be captured, selectively encoded, and optionally transmitted between participants over a session. Hints indicative of which portions of the HDI may have changed are collected and used to select areas of HDI for processing. Changed HDI is encoded using an encoding process selected from a number of encoding processes by determining which process is likely to efficiently encode that portion of the HDI. Where the HDI is divided into tiles for processing the encoding method selection may take place on a tile-by-tile basis, for example by counting the number of colors in the tile to be encoded. Changed HDI may be transmitted to viewers using paint commands containing pixel information and copy commands indicating that a portion of the HDI has been moved.