//
// PDFNet Copyright (c) 2001-2008 by PDFTron Systems Inc. All Rights Reserved.
//

using System;
using System.Drawing;
using System.Drawing.Imaging;

using pdftron;
using pdftron.Common;
using pdftron.PDF;
using pdftron.SDF;

namespace ImageExtractTestCS
{
	class ImageExtractTest
	{
		/// <summary>
		///-----------------------------------------------------------------------------------
		/// This sample illustrates one approach to PDF image extraction 
		/// using PDFNet.
		/// 
		/// Note: Besides direct image export, you can also convert PDF images 
		/// to GDI+ Bitmap, or extract uncompressed/compressed image data directly 
		/// using element.GetImageData() (e.g. as illustrated in ElementReaderAdv 
		/// sample project).
		///-----------------------------------------------------------------------------------
		/// </summary>

		static int image_counter = 0;

		// Relative path to the folder containing test files.
		static string input_path =  "../../../../TestFiles/";
		static string output_path = "../../../../TestFiles/Output/";

		static void ImageExtract(ElementReader reader) 
		{
			Element element; 
			while ((element = reader.Next()) != null)
			{
				switch (element.GetType()) 
				{
					case Element.Type.e_image:
					case Element.Type.e_inline_image:
					{
						Console.WriteLine("--> Image: {0}", ++image_counter);
						Console.WriteLine("    Width: {0}", element.GetImageWidth());
						Console.WriteLine("    Height: {0}", element.GetImageHeight());
						Console.WriteLine("    BPC: {0}", element.GetBitsPerComponent());

						Matrix2D ctm = element.GetCTM();
						double x2=1, y2=1;
						ctm.Mult(ref x2, ref y2);
						Console.WriteLine("    Coords: x1={0}, y1={1}, x2={2}, y2={3}", ctm.m_h, ctm.m_v, x2, y2);

						if (element.GetType() == Element.Type.e_image) 
						{
							string fname = output_path + "image_extract1_" + image_counter.ToString();
							pdftron.PDF.Image image = new pdftron.PDF.Image(element.GetXObject());
							image.Export(fname);  // or ExporAsPng() or ExporAsTiff() ...

							// Convert PDF bitmap to GDI+ Bitmap...
							//Bitmap bmp = element.GetBitmap();
							//bmp.Save(fname, ImageFormat.Png);
							//bmp.Dispose();

							// Instead of converting PDF images to a Bitmap, you can also extract 
							// uncompressed/compressed image data directly using element.GetImageData() 
							// as illustrated in ElementReaderAdv sample project.
						}
						break;
					}
					case Element.Type.e_form: // Process form XObjects
					{
						reader.FormBegin(); 
						ImageExtract(reader);
						reader.End(); 
						break; 
					}
				}
			}
		}

		static void Main(string[] args)
		{
			PDFNet.Initialize();
			PDFNet.SetResourcesPath("../../../../../resources");

			// Example 1: 
			// Extract images by traversing the display list for 
			// every page. With this approach it is possible to obtain 
			// image positioning information and DPI.
			try	
			{
				PDFDoc doc = new PDFDoc(input_path + "newsletter.pdf");
				doc.InitSecurityHandler();

				ElementReader reader = new ElementReader();
				PageIterator itr;
				for (itr=doc.GetPageIterator(); itr.HasNext(); itr.Next())	
				{				
					reader.Begin(itr.Current());
					ImageExtract(reader);
					reader.End();
				}

				doc.Close();
				Console.WriteLine("Done.");
			}
			catch (PDFNetException e)
			{
				Console.WriteLine(e.Message);
			}

			Console.WriteLine("----------------------------------------------------------------");

			// Example 2: 
			// Extract images by scanning the low-level document.
			try	
			{
				PDFDoc doc = new PDFDoc(input_path + "newsletter.pdf");
				doc.InitSecurityHandler();
				image_counter = 0;

				SDFDoc cos_doc = doc.GetSDFDoc();
				int num_objs = cos_doc.XRefSize();
				for (int i=1; i<num_objs; ++i)
				{
					Obj obj = cos_doc.GetObj(i);
					if (obj!=null && !obj.IsFree()&& obj.IsStream()) 
					{
						// Process only images
						DictIterator itr = obj.Find("Subtype");
						if (!itr.HasNext() || itr.Value().GetName() != "Image") 
							continue; 

						itr = obj.Find("Type");
						if (!itr.HasNext() || itr.Value().GetName() != "XObject") 
							continue;

						pdftron.PDF.Image image = new pdftron.PDF.Image(obj);

						Console.WriteLine("--> Image: {0}", ++image_counter);
						Console.WriteLine("    Width: {0}", image.GetImageWidth());
						Console.WriteLine("    Height: {0}", image.GetImageHeight());
						Console.WriteLine("    BPC: {0}", image.GetBitsPerComponent());

						string fname = output_path + "image_extract2_" + image_counter.ToString();
						image.Export(fname);  // or ExporAsPng() or ExporAsTiff() ...

						// Convert PDF bitmap to GDI+ Bitmap...
						//Bitmap bmp = image.GetBitmap();
						//bmp.Save(fname, ImageFormat.Png);
						//bmp.Dispose();

						// Instead of converting PDF images to a Bitmap, you can also extract 
						// uncompressed/compressed image data directly using element.GetImageData() 
						// as illustrated in ElementReaderAdv sample project.
					}
				}

				doc.Close();
				Console.WriteLine("Done.");
			}
			catch (PDFNetException e)
			{
				Console.WriteLine(e.Message);
			}


			PDFNet.Terminate();
		}
	}
}