In this tutorial, you will create a C/C++ Linux console application and use ImageGear to load PDF image and convert it to a new raster format.

1. Create file ig_sample.cpp with the content below using gedit Linux utility:

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   #include <iostream> #include "gear.h" #include "i_PDF.h" int main(int argc, char* argv[]) { // Number of ImageGear errors that occurred AT_ERRCOUNT nErrCount = 0; // Image handle HIGEAR hImage = (HIGEAR)NULL; // By default, save the image as BMP uncompressed AT_LMODE outputFormat = IG_SAVE_BMP_UNCOMP; if (argc < 3) { std::cout << "Usage: ./ig_sample <input_pdf_file> <output_file> <output_format>\n"; std::cout << "Where output_format can be BMP, PNG, JPG, TIF\n"; exit(1); } if (argc >= 4) // output format has been passed { if (strcmp(argv[2], "BMP") == 0) outputFormat = IG_SAVE_BMP_UNCOMP; else if (strcmp(argv[3], "PNG") == 0) outputFormat = IG_SAVE_PNG; else if (strcmp(argv[3], "JPG") == 0) outputFormat = IG_SAVE_JPG; else if (strcmp(argv[3], "TIF") == 0) outputFormat = IG_SAVE_TIF_UNCOMP; } // Initialize ImageGear nErrCount = IG_initialize(NULL, 0, FALSE); if (nErrCount != 0) { exit(-1); } // License ImageGear with a Runtime License // Uncomment the next three lines and update all the parameters to // these licensing functions to use Runtime Licensing //IG_lic_solution_name_set("YourSolutionName"); //IG_lic_solution_key_set(12345, 12345, 12345, 12345); //IG_lic_OEM_license_key_set("2.0..."); // Initialize PDF component IG_comm_comp_attach("PDF"); IG_PDF_initialize(NULL); // Load image file nErrCount = IG_load_file(argv[1], &hImage); if (nErrCount != 0) { exit(-1); } // Check if loaded image is valid if (IG_image_is_valid(hImage)) { // Rasterize PDF image HIGEAR hImageRasterized; nErrCount = IG_vector_data_to_dib(hImage, &hImageRasterized); if (nErrCount == 0) { // Save the PDF image with the new raster format nErrCount = IG_save_file(hImageRasterized, argv[2], outputFormat); // Delete rasterized image IG_image_delete(hImageRasterized); } // Delete the image IG_image_delete(hImage); } if (nErrCount != 0) { exit(-1); } // Terminate PDF component IG_PDF_terminate(); // Close ImageGear IG_close(NULL); return 0; }

   The above sample takes at least  two arguments, an input PDF filename and an output image filename where the resulting output image will be stored.
   A third optional parameter may be used to specify the format of the output image file.
   By default, the output format is BMP.

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   #include "gear.h" #include "i_PDF.h"

   The header files that are necessary for the main ImageGear functionality and for working with PDF component.

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   // Initialize ImageGear nErrCount = IG_initialize(NULL, 0, FALSE);

   This function initializes the ImageGear engine. This line is required before any other ImageGear function calls on Linux.

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   // License ImageGear

   To unlock the toolkit for deployment, you must call the IG_lic_solution_name_set(), IG_lic_solution_key_set() and possibly the IG_lic_OEM_license_key_set() functions.
   See Licensing section for more details.

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   // Initialize PDF component IG_comm_comp_attach("PDF"); IG_PDF_initialize(NULL);

   The first function attaches the PDF component to the main ImageGear module. The second one initializes the PDF engine.

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   // Load image file nErrCount = IG_load_file(argv[1], &hImage);

   This function loads the input image. The first parameter is the name of the image file. The second parameter is a  returned handle to the loaded image. This handle is used in all subsequent operations on the loaded image.

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   // Check if loaded image is valid if (IG_image_is_valid(hImage))

   This function checks whether the image handle is valid or not.

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   // Rasterize PDF image HIGEAR hImageRasterized; nErrCount = IG_vector_data_to_dib(hImage, &hImageRasterized);

   This function flushes the PDF data to device independent raster format and returns a handle of new raster image in hImageRasterized argument.

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   // Save the rotated image with the new raster format nErrCount = IG_save_file(hImageRasterized, argv[2], outputFormat);

   This function saves the rasterized image to the specified file in the specified format.

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   // Delete the image IG_image_delete(hImage);

   This function deletes the image handle after it is no longer needed and releases all the memory used by the image.

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   // Terminate PDF component IG_PDF_terminate();

   This function de-initializes the PDF engine.

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   // Close ImageGear IG_close(NULL);

   This function closes ImageGear and should be called before the application program exits.

2. Create CMakeList.txt file with the following content:

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   cmake_minimum_required(VERSION 2.6 FATAL_ERROR) project(ig_sample) # relative path to your ImageGear include directory; include_directories(${CMAKE_SOURCE_DIR}/../../include) # relative path to your ImageGear bin directory; link_directories(${CMAKE_SOURCE_DIR}/../../bin/) # reference to main ImageGear library IGCORE18 set(LIBRARY_NAME IGCORE18) add_definitions(-D_UNIX64) # specify input and output files; add_executable(ig_sample ig_sample.cpp) # link the program with ImageGear library. target_link_libraries(ig_sample ${LIBRARY_NAME}

3. Run the following commands:
   cmake.
   make

   The executable file, ig_sample, will be created in the current directory.

4. Copy any valid PDF file to the current directory (say, sample.pdf) and run the program:

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   ./ig_sample sample.pdf sample.png PNG

   The file, sample.pdf, will be loaded, rasterized and saved as a PNG image in sample.png.