FindCandidateFormFieldsCommand Class

Summary

Extracts the candidate form fields from a bitmap using various options. There are two types of fields that can be extracted: OMR fields and text fields.

Syntax

C++/CLI

Java

Python

public class FindCandidateFormFieldsCommand : RasterCommand

public class FindCandidateFormFieldsCommand 
    extends RasterCommand

public: 
   ref class FindCandidateFormFieldsCommand : RasterCommand

class FindCandidateFormFieldsCommand(RasterCommand):

Remarks

If an image is skewed, deskew it first before running FindCandidateFormFieldsCommand.

FindCandidateFormFieldsCommand supports 8-bit, 12-bit and 16-bit grayscale images, as well as 24-bit, 32-bit, 48-bit, and 64-bit colored images. This function does not support 32-bit grayscale images. If a 32-bit grayscale image is passed to this function, it returns the ERROR_GRAY32_UNSUPPORTED error code.

FindCandidateFormFieldsCommand does not support setting rectangular regions.

Example

Runs the FindCandidateFormFieldsCommand on an image.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing.Core; 
 
 
public void FindCandidateFormFieldsCommandExample() 
{ 
 
   RasterCodecs codecs = new RasterCodecs(); 
 
   RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, @"Forms\Forms to be Recognized\OMR\AnswerSheet_Pattern.jpg"), 0, Leadtools.Codecs.CodecsLoadByteOrder.Bgr, 1, 1); 
   FindCandidateFormFieldsCommand findFields = new FindCandidateFormFieldsCommand(); 
   findFields.HorizontalLineMinimumLength = (char)10; 
   findFields.VerticalLineMinimumLength = (char)3; 
   findFields.Run(image); 
 
   TextField[] textFields = findFields.TextFieldAreas; 
   OMRField[] omrFields = findFields.OMRFieldAreas; 
 
 
   foreach (TextField field in textFields) 
   { 
      // Function TODO : Drawing rectangle field.Bounds 
      // Function TODO : Drawing rectangle field.FilledAreaBounds 
   } 
          
   foreach (OMRField field in omrFields) 
   { 
      if (field.FieldType == BoxOMR) 
      { 
         // Function TODO : Drawing rectangle field.UnFilledBound 
      } 
      { 
         // Function TODO : Drawing circle field.UnFilledBound 
      } 
   } 
          
   image.Dispose(); 
 
   codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}

Requirements

Target Platforms

Reference

FindCandidateFormFieldsCommand Members

Leadtools.ImageProcessing.Core Namespace

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Help Version 22.0.2023.3.31

Leadtools.ImageProcessing.Core Assembly

Introduction

Getting Started

Namespaces

Leadtools.ImageProcessing.Core Namespace

Assemblies