RPA Robotic Process Automation – Read PDF with Scanned Image and Hindi Text – C#

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RPA Robotic Process Automation – Read PDF with Scanned Image and Hindi Text – C#

printable version:
ByteScout-Robotic-Process-Automation-C-sharp-C-sharp.pdf

How to read PDF with scanned image and hindi text in C# with ByteScout Robotic Process Automation

ByteScout Robotic Process Automation: set of tools for rapid implementation of robotic process automation applications.

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Program.cs

      using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Drawing.Imaging;
using Bytescout.PDFExtractor;
using Bytescout.PDF;
using System.Diagnostics;

namespace ReadPDFWithImageHindiText
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                // Files
                string fileName = "hindi_text_with_image.pdf";
                string destFileName = "output_hindi_text_with_image.pdf";
                string destFileName_serachable = "output_hindi_text_with_image_searchable.pdf";

                // Read all text from pdf file
                string allTextExtracted = "";
                using (TextExtractor extractor = new TextExtractor())
                {
                    // Load PDF document
                    extractor.LoadDocumentFromFile(fileName);

                    // Read all text directly
                    allTextExtracted = extractor.GetText();
                }

                // Get image from pdf file
                MemoryStream memoryStream = new MemoryStream();
                using (ImageExtractor extractor = new ImageExtractor())
                {
                    // Load PDF document
                    extractor.LoadDocumentFromFile(fileName);

                    if (extractor.GetFirstImage())
                    {
                        extractor.SaveCurrentImageToStream(memoryStream, ImageFormat.Png);
                    }
                }

                // Load image from file to System.Drawing.Image object (we need it to get the image resolution)
                using (System.Drawing.Image sysImage = System.Drawing.Image.FromStream(memoryStream))
                {
                    // Compute image size in PDF units (Points)
                    float widthInPoints = sysImage.Width / sysImage.HorizontalResolution * 72f;
                    float heightInPoints = sysImage.Height / sysImage.VerticalResolution * 72f;

                    // Create new PDF document
                    using (Document outPdfDocument = new Document())
                    {
                        outPdfDocument.RegistrationName = "demo";
                        outPdfDocument.RegistrationKey = "demo";

                        // Create page of computed size
                        Page page = new Page(widthInPoints, heightInPoints);

                        // Add page to the document
                        outPdfDocument.Pages.Add(page);

                        Canvas canvas = page.Canvas;

                        // Create Bytescout.PDF.Image object from loaded image
                        Image pdfImage = new Image(sysImage);

                        // Draw the image
                        canvas.DrawImage(pdfImage, 0, 0, widthInPoints, heightInPoints);

                        // Dispose the System.Drawing.Image object to free resources
                        sysImage.Dispose();

                        // Create brush
                        SolidBrush transparentBrush = new SolidBrush(new ColorGray(0));

                        // ... and make it transparent
                        transparentBrush.Opacity = 0;

                        // Draw text with transparent brush
                        // Need to set Font which supports hindi characters.
                        Font font16 = new Font("Arial Unicode MS", 16);
                        canvas.DrawString(allTextExtracted, font16, transparentBrush, 40, 40);

                        // Save document to file
                        outPdfDocument.Save(destFileName);
                    }
                }


                // Make PDF file with hindi text searchable to OCR.
                using (SearchablePDFMaker searchablePDFMaker = new SearchablePDFMaker())
                {
                    //Load PDF document
                    searchablePDFMaker.LoadDocumentFromFile(destFileName);

                    // Set the location of "tessdata" folder containing language data files
                    /*
                     * It used following files for hindi language support. Need to put these files into "testdata" folder. Below location contains these files.
                     * https://github.com/tesseract-ocr/tessdata/tree/3.04.00 
                     hin.traineddata
                     hin.cube.bigrams
                     hin.cube.lm
                     hin.cube.nn
                     hin.cube.params
                     hin.cube.word-freq
                     hin.tesseract_cube.nn
                     */
                    searchablePDFMaker.OCRLanguageDataFolder = @"c:\Program Files\Bytescout PDF Extractor SDK\Redistributable\net2.00\tessdata\";

                    // Set OCR language
                    searchablePDFMaker.OCRLanguage = "hin";

                    // Need to set Font which supports hindi characters
                    searchablePDFMaker.LabelingFont = "Arial Unicode MS";

                    // Set PDF document rendering resolution
                    searchablePDFMaker.OCRResolution = 300;

                    searchablePDFMaker.MakePDFSearchable(destFileName_serachable);
                }

                // Open document in default PDF viewer app
                Process.Start(destFileName_serachable);
            }
            catch (Exception ex)
            {
                Console.WriteLine("ERROR:" + ex.Message);
            }

            Console.ReadLine();
        }
    }
}

ReadPDFWithImageHindiText.csproj

      <?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    <ProjectGuid>{99735776-2956-463D-9795-EBCE16928C30}</ProjectGuid>
    <OutputType>Exe</OutputType>
    <RootNamespace>ReadPDFWithImageHindiText</RootNamespace>
    <AssemblyName>ReadPDFWithImageHindiText</AssemblyName>
    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
    <FileAlignment>512</FileAlignment>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <PlatformTarget>AnyCPU</PlatformTarget>
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>bin\Debug\</OutputPath>
    <DefineConstants>DEBUG;TRACE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <PlatformTarget>AnyCPU</PlatformTarget>
    <DebugType>pdbonly</DebugType>
    <Optimize>true</Optimize>
    <OutputPath>bin\Release\</OutputPath>
    <DefineConstants>TRACE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="Bytescout.PDF, Version=1.8.2.254, Culture=neutral, PublicKeyToken=f7dd1bd9d40a50eb, processorArchitecture=MSIL">
      <SpecificVersion>False</SpecificVersion>
      <HintPath>c:\Program Files\Bytescout PDF SDK\net2.0\Bytescout.PDF.dll</HintPath>
    </Reference>
    <Reference Include="Bytescout.PDFExtractor, Version=9.1.0.3170, Culture=neutral, PublicKeyToken=f7dd1bd9d40a50eb, processorArchitecture=MSIL">
      <SpecificVersion>False</SpecificVersion>
      <HintPath>c:\Program Files\Bytescout PDF Extractor SDK\net2.00\Bytescout.PDFExtractor.dll</HintPath>
    </Reference>
    <Reference Include="System" />
    <Reference Include="System.Data" />
    <Reference Include="System.Drawing" />
    <Reference Include="System.Xml" />
  </ItemGroup>
  <ItemGroup>
    <Compile Include="Program.cs" />
  </ItemGroup>
  <ItemGroup>
    <None Include="hindi_text_with_image.pdf">
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </None>
  </ItemGroup>
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
</Project>

ReadPDFWithImageHindiText.sln

      
Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio 15
VisualStudioVersion = 15.0.27703.2026
MinimumVisualStudioVersion = 10.0.40219.1
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ReadHindiText", "ReadPDFWithImageHindiText.csproj", "{99735776-2956-463D-9795-EBCE16928C30}"
EndProject
Global
	GlobalSection(SolutionConfigurationPlatforms) = preSolution
		Debug|Any CPU = Debug|Any CPU
		Release|Any CPU = Release|Any CPU
	EndGlobalSection
	GlobalSection(ProjectConfigurationPlatforms) = postSolution
		{99735776-2956-463D-9795-EBCE16928C30}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
		{99735776-2956-463D-9795-EBCE16928C30}.Debug|Any CPU.Build.0 = Debug|Any CPU
		{99735776-2956-463D-9795-EBCE16928C30}.Release|Any CPU.ActiveCfg = Release|Any CPU
		{99735776-2956-463D-9795-EBCE16928C30}.Release|Any CPU.Build.0 = Release|Any CPU
	EndGlobalSection
	GlobalSection(SolutionProperties) = preSolution
		HideSolutionNode = FALSE
	EndGlobalSection
	GlobalSection(ExtensibilityGlobals) = postSolution
		SolutionGuid = {3ABE3EEF-B212-4E8B-9A74-67A52FD333AC}
	EndGlobalSection
EndGlobal