var opt = host.StructExportOptions;
opt.AntiAliasingType = host.cdrNormalAntiAliasing; //getting error: Cannot set property 'AntiAliasingType' of undefined
opt.ImageType = host.cdrRGBColorImage;
opt.Overwrite = true;
opt.ResolutionY = 300;
exportFileName = "d:\\test.png";
host.ActiveDocument.Export(exportFileName,host.cdrPNG, host.cdrSelection, opt, undefined);
i mean instead filter= host.ActiveDocument.ExportBitmap("d:\\test.png", host.cdrPNG, ...
try use host.ActiveDocument.ExportBitmap("d:\\test.png", host.cdrPNG, ...