//// This code is part of Document Solutions for Imaging demos.// Copyright (c) MESCIUS inc. All rights reserved.//using System.IO;using System.Drawing;using GrapeCity.Documents.Drawing;using GrapeCity.Documents.Text;using GrapeCity.Documents.Imaging;using GCTEXT = GrapeCity.Documents.Text;using GCDRAW = GrapeCity.Documents.Drawing;
namespace DsImagingWeb.Demos{    // This sample demonstrates how quantization and dithering    // algorithms can be used to convert a 24 bits per pixel image    // to a reasonably looking image with a limited palette    // (16 colors, 4 bits per pixel).    public class LimitedPalette    {        public GcBitmap GenerateImage(Size pixelSize, float dpi, bool opaque, string[] sampleParams = null)        {            opaque = true;
            var bmp = new GcBitmap(pixelSize.Width, pixelSize.Height, opaque, dpi, dpi);            using (var origBmp = new GcBitmap())            {                // Load a sample photo:                var imagePath = Path.Combine("Resources", "ImagesBis", "clivia.jpg");                using (var stm = new FileStream(imagePath, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, FileOptions.RandomAccess))                    origBmp.Load(stm);
                // Resize the original photo so we can place 4 samples of it                // on the resulting bitmap:                int w = pixelSize.Width / 2;                int h = pixelSize.Height / 2;                using (var sizedBmp = origBmp.Resize(w, h, InterpolationMode.Cubic))                {                    // Resized original image:                    bmp.BitBlt(sizedBmp, 0, 0);
                    // Simple dithering:                    using (var ind = sizedBmp.ToIndexed4bppBitmap(DitheringMethod.Stucki))                    using (var bm = ind.ToGcBitmap())                        bmp.BitBlt(bm, w, 0);
                    // Octree quantizer algorithm without dithering:                    using (var ind = sizedBmp.ToIndexed4bppBitmap(16))                    using (var bm = ind.ToGcBitmap())                        bmp.BitBlt(bm, 0, h);
                    // Octree quantizer + dithering:                    var pal = sizedBmp.GenerateOctreePalette(16);                    using (var ind = sizedBmp.ToIndexed4bppBitmap(pal, DitheringMethod.Stucki))                    using (var bm = ind.ToGcBitmap())                        bmp.BitBlt(bm, w, h);                }
                // Add borders between the quadrants, and captions for each:                var lineh = 2;                using (var g = bmp.CreateGraphics(null))                {                    var foreColor = Color.Yellow;                    var backColor = Color.Blue;                    var font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "FreeMono.ttf"));                    g.DrawLine(w, 0, w, h * 2, new GCDRAW.Pen(Color.Gray, lineh * 2));                    g.DrawLine(0, h, w * 2, h, new GCDRAW.Pen(Color.Gray, lineh * 2));                    var tf = new TextFormat() { Font = font, FontSize = 18, ForeColor = foreColor, BackColor = backColor, FontBold = true };                    var th = g.MeasureString("QWERTY", tf).Height;                    g.DrawString(" Original image (24bpp) ", tf, new PointF(0, h - th + lineh));                    g.DrawString(" Simple dithering (4bpp) ", tf, new PointF(w + lineh, h - th + lineh));                    g.DrawString(" Octree quantizer (4bpp) ", tf, new PointF(0, h * 2 + lineh - th + lineh));                    g.DrawString(" Octree + dithering (4bpp) ", tf, new PointF(w + lineh, h * 2 + lineh - th + lineh));                }            }            return bmp;        }    }}