//
// This code is part of Document Solutions for Imaging demos.
// Copyright (c) MESCIUS inc. All rights reserved.
//
using System;
using System.IO;
using System.Drawing;
using System.Collections.Generic;
using System.Linq;
using GrapeCity.Documents.Drawing;
using GrapeCity.Documents.Text;
using GrapeCity.Documents.Imaging;

namespace DsImagingWeb.Demos
{
    // This sample takes a color JPEG, converts it to different image types
    // (such as b/w and grayscale) and creates a multi-frame TIFF from those
    // images.
    public class ImageTypesInTiff
    {
        public string DefaultMime { get => Common.Util.MimeTypes.TIFF; }

        public Stream GenerateImageStream(string targetMime, Size pixelSize, float dpi, bool opaque, string[] sampleParams = null)
        {
            if (targetMime != Common.Util.MimeTypes.TIFF)
                throw new Exception("This sample only supports TIFF output format.");

            var path = Path.Combine("Resources", "Images", "minerva.jpg");

            var ms = new MemoryStream();
            using (var tw = new GcTiffWriter(ms))
            using (var bmp = new GcBitmap(path))
            {
                // Using the green channel produces a marginally better result for this photo.
                // For a much better bi-level image produced by dithering, see DitheringInTiff.
                using (var f = bmp.ToBilevelBitmap(ColorChannel.Green))
                    tw.AppendFrame(f);
                using (var f = bmp.ToGrayscaleBitmap())
                    tw.AppendFrame(f);
                // 4bpp allows from 8 to 16 colors, we use max (16):
                using (var f = bmp.ToIndexed4bppBitmap(16))
                    tw.AppendFrame(f);
                // 8bpp allows from 8 to 256 colors, we use max (256):
                using (var f = bmp.ToIndexed8bppBitmap(256))
                    tw.AppendFrame(f);
                tw.AppendFrame(bmp);
            }
            ms.Seek(0, SeekOrigin.Begin);
            return ms;
        }
    }
}