// 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);
// Setup color for the ellipse border.
ImGearRGBQuad igRGBQuadEllipseBorder = new ImGearRGBQuad(60, 60, 255);
// Create ellipse with a solid 4 pixel border and opacity of 127 (50%)
ImGearARTEllipse igARTEllipse = new ImGearARTEllipse(
igRectangle, igRGBQuadEllipse, igRGBQuadEllipseBorder, ImGearARTPenStyle.SOLID, 4, 127
);
// Add the annotation to the ARTPage.
igARTPage.AddMark(igARTEllipse, ImGearARTCoordinatesType.IMAGE_COORD);