// Setup rectangle for the ellipse mark's location.
ImGearRectangle igRectangle = new ImGearRectangle(10, 10, 300, 100);
// Setup color for the ellipse.
ImGearRGBQuad igRGBQuadEllipse = new ImGearRGBQuad(40, 40, 200);
// Create ellipse with highlight on.
ImGearARTFilledEllipse igARTFilledEllipse = new ImGearARTFilledEllipse(
igRectangle, igRGBQuadEllipse, true
);
// Add the annotation to the ARTPage.
igARTPage.AddMark(igARTFilledEllipse, ImGearARTCoordinatesType.IMAGE_COORD);