ByteScout PDF Suite – C# – Select Region And Perform OCR

Home
/
Articles
/
ByteScout PDF Suite – C# – Select Region And Perform OCR

printable version:
ByteScout-PDF-Suite-C-sharp-Select-Region-And-Perform-OCR.pdf

How to select region and perform OCR in C# using ByteScout PDF Suite

Learning is essential in computer world and the tutorial below will demonstrate how to select region and perform OCR in C#

Source code documentation samples give simple and easy method to install a needed feature into your application. Want to select region and perform OCR in your C# app? ByteScout PDF Suite is designed for it. ByteScout PDF Suite is the set that includes 6 SDK products to work with PDF from generating rich PDF reports to extracting data from PDF documents and converting them to HTML. This bundle includes PDF (Generator) SDK, PDF Renderer SDK, PDF Extractor SDK, PDF to HTML SDK, PDF Viewer SDK and PDF Generator SDK for Javascript.

This prolific sample source code in C# for ByteScout PDF Suite contains various functions and other necessary options you should do calling the API to select region and perform OCR. Just copy and paste the code into your C# application’s code and follow the instructions. If you want to use these C# sample examples in one or many applications then they can be used easily.

Our website gives trial version of ByteScout PDF Suite for free. It also includes documentation and source code samples.

On-demand (REST Web API) version:
Web API (on-demand version)

On-premise offline SDK for Windows:
60 Day Free Trial (on-premise)

Form1.Designer.cs

      namespace SelectRegionAndPerformOCR
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1));
            this.toolStrip1 = new System.Windows.Forms.ToolStrip();
            this.toolStripButton1 = new System.Windows.Forms.ToolStripButton();
            this.pdfViewerControl1 = new Bytescout.PDFViewer.PDFViewerControl();
            this.btnRunOCR = new System.Windows.Forms.Button();
            this.label1 = new System.Windows.Forms.Label();
            this.toolStrip1.SuspendLayout();
            this.SuspendLayout();
            // 
            // toolStrip1
            // 
            this.toolStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.toolStripButton1});
            this.toolStrip1.Location = new System.Drawing.Point(0, 0);
            this.toolStrip1.Name = "toolStrip1";
            this.toolStrip1.Size = new System.Drawing.Size(971, 25);
            this.toolStrip1.TabIndex = 0;
            this.toolStrip1.Text = "toolStrip1";
            // 
            // toolStripButton1
            // 
            this.toolStripButton1.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point);
            this.toolStripButton1.Image = ((System.Drawing.Image)(resources.GetObject("toolStripButton1.Image")));
            this.toolStripButton1.ImageTransparentColor = System.Drawing.Color.Magenta;
            this.toolStripButton1.Name = "toolStripButton1";
            this.toolStripButton1.Size = new System.Drawing.Size(114, 22);
            this.toolStripButton1.Text = "Load document";
            this.toolStripButton1.Click += new System.EventHandler(this.toolStripButton1_Click);
            // 
            // pdfViewerControl1
            // 
            this.pdfViewerControl1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
            | System.Windows.Forms.AnchorStyles.Left) 
            | System.Windows.Forms.AnchorStyles.Right)));
            this.pdfViewerControl1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
            this.pdfViewerControl1.Location = new System.Drawing.Point(12, 28);
            this.pdfViewerControl1.MouseMode = Bytescout.PDFViewer.MouseMode.Selection;
            this.pdfViewerControl1.Name = "pdfViewerControl1";
            this.pdfViewerControl1.RegistrationKey = null;
            this.pdfViewerControl1.RegistrationName = null;
            this.pdfViewerControl1.ResetRotationOnPageChange = false;
            this.pdfViewerControl1.Scale = 100;
            this.pdfViewerControl1.SelectionColor = System.Drawing.Color.Red;
            this.pdfViewerControl1.ShowImageObjects = true;
            this.pdfViewerControl1.ShowTextObjects = true;
            this.pdfViewerControl1.ShowVectorObjects = true;
            this.pdfViewerControl1.Size = new System.Drawing.Size(766, 490);
            this.pdfViewerControl1.TabIndex = 1;
            // 
            // btnRunOCR
            // 
            this.btnRunOCR.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
            this.btnRunOCR.Enabled = false;
            this.btnRunOCR.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point);
            this.btnRunOCR.Location = new System.Drawing.Point(784, 77);
            this.btnRunOCR.Name = "btnRunOCR";
            this.btnRunOCR.Size = new System.Drawing.Size(175, 39);
            this.btnRunOCR.TabIndex = 2;
            this.btnRunOCR.Text = "Run OCR";
            this.btnRunOCR.UseVisualStyleBackColor = true;
            this.btnRunOCR.Click += new System.EventHandler(this.btnRunOCR_Click);
            // 
            // label1
            // 
            this.label1.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
            this.label1.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point);
            this.label1.Location = new System.Drawing.Point(784, 28);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(175, 46);
            this.label1.TabIndex = 3;
            this.label1.Text = "Load document, select region and press \"Run OCR\" button";
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(971, 530);
            this.Controls.Add(this.label1);
            this.Controls.Add(this.btnRunOCR);
            this.Controls.Add(this.pdfViewerControl1);
            this.Controls.Add(this.toolStrip1);
            this.Name = "Form1";
            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
            this.Text = "Form1";
            this.toolStrip1.ResumeLayout(false);
            this.toolStrip1.PerformLayout();
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.ToolStrip toolStrip1;
        private System.Windows.Forms.ToolStripButton toolStripButton1;
        private Bytescout.PDFViewer.PDFViewerControl pdfViewerControl1;
        private System.Windows.Forms.Button btnRunOCR;
        private System.Windows.Forms.Label label1;
    }
}

ON-PREMISE OFFLINE SDK

60 Day Free Trial or Visit ByteScout PDF Suite Home Page

Explore ByteScout PDF Suite Documentation

Explore Samples

Sign Up for ByteScout PDF Suite Online Training

ON-DEMAND REST WEB API

Get Your API Key

Explore Web API Docs

Explore Web API Samples

Form1.cs

      using System;
using System.Drawing;
using System.Windows.Forms;
using Bytescout.PDFExtractor;

namespace SelectRegionAndPerformOCR
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            using (OpenFileDialog openFileDialog = new OpenFileDialog())
            {
                openFileDialog.Title = @"Open Document";
                openFileDialog.Filter = @"All Supported Formats|*.pdf;*.jpg;*.jpeg;*.png;*.tif;*.tiff;*.bmp|PDF Files (*.pdf)|*.pdf|Image Files (*.jpg;*.png;*.tif;*.tiff;*.bmp)|*.jpg;*.jpeg;*.png;*.tif;*.tiff;*.bmp|All Files|*.*";

                if (openFileDialog.ShowDialog() == DialogResult.OK)
                {
                    pdfViewerControl1.InputFile = openFileDialog.FileName;

                    btnRunOCR.Enabled = true;
                }
            }
        }

        private void btnRunOCR_Click(object sender, EventArgs e)
        {
            TextExtractor extractor = new TextExtractor();
            extractor.RegistrationName = "demo";
            extractor.RegistrationKey = "demo";

            // Load sample PDF document
            extractor.LoadDocumentFromFile(pdfViewerControl1.InputFile);

            // Enable Optical Character Recognition (OCR)
            // in .Auto mode (SDK automatically checks if needs to use OCR or not)
            extractor.OCRMode = OCRMode.Auto;

            // Set the location of "tessdata" folder containing language data files
            extractor.OCRLanguageDataFolder = @"c:\Program Files\Bytescout PDF Extractor SDK\net4.00\tessdata\";

            // Set OCR language
            extractor.OCRLanguage = "eng"; // "eng" for english, "deu" for German, "fra" for French, "spa" for Spanish etc - according to files in /tessdata
            // Find more language files at https://github.com/tesseract-ocr/tessdata/tree/3.04.00

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


            // Set the extraction area to the viewer's selection rectangle
            RectangleF[] selection = pdfViewerControl1.SelectionInPoints;
            if (selection.Length > 0)
                extractor.SetExtractionArea(selection[0]);

            // Show wait cursor
            Cursor = Cursors.WaitCursor;

            try
            {
                // Perform OCR and save result to file
                extractor.SavePageTextToFile(pdfViewerControl1.CurrentPageIndex, "result.txt");
            }
            finally
            {
                // Revert cursor to default
                Cursor = Cursors.Default;
            }
            
            // Cleanup
            extractor.Dispose();

            // Open output file in default associated application
            System.Diagnostics.Process.Start("result.txt");
        }
    }
}

ON-PREMISE OFFLINE SDK

60 Day Free Trial or Visit ByteScout PDF Suite Home Page

Explore ByteScout PDF Suite Documentation

Explore Samples

Sign Up for ByteScout PDF Suite Online Training

ON-DEMAND REST WEB API

Get Your API Key

Explore Web API Docs

Explore Web API Samples

Program.cs

      using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace SelectRegionAndPerformOCR
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}