RGB Raster Compression
Used to specify the RGB (Red/Green/Blue) raster compression mode in a PDF document.
This property affects only true color raster data, not palette color or monochrome raster. By default, true color raster is converted to palette color or monochrome when the conversion can be done without loss of color depth. When using JPEG RGB compression, this default avoidance of true color raster can actually result in larger PDF files than would otherwise be produced. Therefore, if you change the RGB compression mode to JPEG, you also may want to consider setting the Optimize Raster Color Depth property to False. However, doing so may result in unacceptably poor output of rasterized Excel spreadsheets, or any raster data consisting of thin lines.