//// This code is part of Document Solutions for PDF .NET demos.// Copyright (c) MESCIUS inc. All rights reserved.//using System.IO;using System.Drawing;using GrapeCity.Documents.Pdf;using GrapeCity.Documents.Text;using GrapeCity.Documents.Drawing;using GCTEXT = GrapeCity.Documents.Text;using GCDRAW = GrapeCity.Documents.Drawing;
namespace DsPdfWeb.Demos{    // This example shows how SaveAsImageOptions.InterpolationMode affects the result    // when a PDF is saved to raster images using SaveAsJpeg or other SaveAsXXX methods.    public class InterpolationModes    {        public int CreatePDF(Stream stream)        {            // Small image of a QRCode that will be enlarged in PDFs that are then saved as JPEGs:            using var image = GCDRAW.Image.FromFile(Path.Combine("Resources", "ImagesBis", "QRCode-57x57.png"));
            // Create 4 PDFs, each is one page on which the small image is enlarged,            // save each PDF as JPEG with different interpolation modes specified in SaveAsImageOptions:            var tmpNearestNeighbor = Path.GetTempFileName();            MakePDF(image, InterpolationMode.NearestNeighbor).SaveAsJpeg(tmpNearestNeighbor, null,                 new SaveAsImageOptions() { InterpolationMode = InterpolationMode.NearestNeighbor });            using var imgNearestNeighbor = GCDRAW.Image.FromFile(tmpNearestNeighbor);            var tmpLinear = Path.GetTempFileName();            MakePDF(image, InterpolationMode.Linear).SaveAsJpeg(tmpLinear, null,                new SaveAsImageOptions() { InterpolationMode = InterpolationMode.Linear });            using var imgLinear = GCDRAW.Image.FromFile(tmpLinear);            var tmpCubic = Path.GetTempFileName();            MakePDF(image, InterpolationMode.Cubic).SaveAsJpeg(tmpCubic, null,                new SaveAsImageOptions() { InterpolationMode = InterpolationMode.Cubic });            using var imgCubic = GCDRAW.Image.FromFile(tmpCubic);            var tmpDownscale = Path.GetTempFileName();            MakePDF(image, InterpolationMode.Downscale).SaveAsJpeg(tmpDownscale, null,                new SaveAsImageOptions() { InterpolationMode = InterpolationMode.Downscale });            using var imgDownscale = GCDRAW.Image.FromFile(tmpDownscale);
            // Draw each JPEG at its natural size onto a page of the resulting PDF:            var doc = new GcPdfDocument();            var page = doc.NewPage();            page.Graphics.DrawImage(imgNearestNeighbor, page.Bounds, null, ImageAlign.Default);            page = doc.NewPage();            page.Graphics.DrawImage(imgLinear, page.Bounds, null, ImageAlign.Default);            page = doc.NewPage();            page.Graphics.DrawImage(imgCubic, page.Bounds, null, ImageAlign.Default);            page = doc.NewPage();            page.Graphics.DrawImage(imgDownscale, page.Bounds, null, ImageAlign.Default);            // Save the resulting PDF:            doc.Save(stream);            // CLeanup:            File.Delete(tmpNearestNeighbor);            File.Delete(tmpLinear);            File.Delete(tmpCubic);            File.Delete(tmpDownscale);
            // Done:            return doc.Pages.Count;        }
        // InterpolationMode parameter here is only to show in the resulting PDF,        // GcPdfGraphics only supports InterpolationMode.NearestNeighbor:        public GcPdfDocument MakePDF(GCDRAW.Image image, InterpolationMode imode)        {            var tfCaption = new TextFormat            {                Font = StandardFonts.Times,                FontSize = 20,            };            var tf = new TextFormat            {                Font = StandardFonts.Times,                FontSize = 18,            };
            var doc = new GcPdfDocument();            var page = doc.NewPage();            var g = page.Graphics;
            var xpad = 36;            var ypad = 36;            var ip = new PointF(xpad, ypad);            g.DrawString($"SaveAsImageOptions.InterpolationMode is {imode}", tfCaption, ip);            ip.Y *= 2.5f;
            // Draw the original with the original size:            g.DrawImage(image, new RectangleF(ip.X, ip.Y, image.Width, image.Height), null, ImageAlign.Default);            g.DrawString($"⟵ Original image ({image.Width} by {image.Height} pixels)", tf, new PointF(ip.X * 2 + image.Width, ip.Y));            ip.Y += image.Height + ypad;
            // Enlarge the original small image by a factor of 8:            var f = 8;            int twidth = image.Width * f;            int theight = image.Height * f;
            // Draw the enlarged image:            g.DrawImage(image, new RectangleF(ip.X, ip.Y, twidth, theight), null, ImageAlign.StretchImage);            g.DrawString($"Image enlarged to {twidth} by {theight} pixels:", tf, new PointF(ip.X, ip.Y - ypad));
            return doc;        }    }}