PDF3D ReportGen and PDF3D.IO development SDK can be used to convert raster image formats containing elevation data to 3D PDF terrain surface representations.
When loading a PNG image, with compressed 8-bit color lookup mode (246 colors), the GDAL interface will load successfully. By default, it assumes it is an attribute and adds a legend on the side showing the LUT corresponding to the range data in the attribute. For some applications this legend is not needed.
To avoid the legend, go to bindings, select Color RGB mode rather than automatic channel binding. Then the legend bar is not produced.
