HightLight 01

        private static void ExampleHighlightAnnotation01()
        {
            var page = new Document(@"C:\tmp\pdf-sample.pdf").Pages[1];
            var tfa = new TextFragmentAbsorber(@"Adobe\W+Acrobat\W+Reader", new TextSearchOptions(true));
            tfa.Visit(page);
            var points = new Point[tfa.TextFragments[1].Segments.Count * 4];
            byte index = 0;
            foreach (var segment in tfa.TextFragments[1].Segments)
            {
                RectToQuadPoints(segment.Rectangle).CopyTo(points, index);
                index += 4;
            }

            var llx = points.Min(pt => pt.X);
            var lly = points.Min(pt => pt.Y);
            var urx = points.Max(pt => pt.X);
            var ury = points.Max(pt => pt.Y);
            var highLightAnnotation = new Aspose.Pdf.Annotations.HighlightAnnotation(page, new Rectangle(llx, lly, urx, ury))
            {
                //Name = Guid.NewGuid().ToString(),
                Subject = "Highlight",
                Title = "Andruhovski",
                Color = Color.Yellow,
                Modified = DateTime.Now,
                QuadPoints = points
            };
            page.Annotations.Add(highLightAnnotation);
            _document.Save(@"C:\tmp\pdf-sample-0.pdf");
        }