預處理

改善低品質掃描和照片的輸入。使用我們的預處理濾鏡來清潔、拉直和增強困難的圖像，以達到最大的OCR精度。

輸入顏色校正濾鏡

二值化

在IronOCR中輕鬆二值化您的輸入，將圖像轉換為清晰的黑白版本。這個濾鏡有效地將文字從複雜的背景中隔離出來，降低噪聲，使文字提取更輕鬆、更可靠。

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply binarize affect
imageInput.Binarize();

// Export the modified image
imageInput.SaveAsImages("binarize.jpg");

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply binarize affect
imageInput.Binarize();

// Export the modified image
imageInput.SaveAsImages("binarize.jpg");

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput As New OcrImageInput("sample.jpg")

    ' Apply binarize affect
    imageInput.Binarize()

    ' Export the modified image
    imageInput.SaveAsImages("binarize.jpg")
End Using

灰度

將彩色圖像轉換為灰度 - 是為更先進的預處理濾鏡準備圖像的重要步驟。

瞭解如何使用:修正.NET C#中的閱讀圖像顏色

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply grayscale affect
imageInput.ToGrayScale();

// Export the modified image
imageInput.SaveAsImages("grayscale.jpg");

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply grayscale affect
imageInput.ToGrayScale();

// Export the modified image
imageInput.SaveAsImages("grayscale.jpg");

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput As New OcrImageInput("sample.jpg")

    ' Apply grayscale affect
    imageInput.ToGrayScale()

    ' Export the modified image
    imageInput.SaveAsImages("grayscale.jpg")
End Using

更改像素顏色

替換圖像中的特定顏色范圍，使您可以在OCR之前去除水印、彩色背景或其他分心元素。

瞭解如何使用:修正.NET C#中的閱讀圖像顏色

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");
IronSoftware.Drawing.Color currentColor = new IronSoftware.Drawing.Color("#DB645C");
IronSoftware.Drawing.Color newColor = IronSoftware.Drawing.Color.DarkCyan;

// Replace color
imageInput.ReplaceColor(currentColor, newColor, 80);

// Export the modified image
imageInput.SaveAsImages("replaceColor");

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");
IronSoftware.Drawing.Color currentColor = new IronSoftware.Drawing.Color("#DB645C");
IronSoftware.Drawing.Color newColor = IronSoftware.Drawing.Color.DarkCyan;

// Replace color
imageInput.ReplaceColor(currentColor, newColor, 80);

// Export the modified image
imageInput.SaveAsImages("replaceColor");

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput As New OcrImageInput("sample.jpg")
    Dim currentColor As New IronSoftware.Drawing.Color("#DB645C")
    Dim newColor As IronSoftware.Drawing.Color = IronSoftware.Drawing.Color.DarkCyan

    ' Replace color
    imageInput.ReplaceColor(currentColor, newColor, 80)

    ' Export the modified image
    imageInput.SaveAsImages("replaceColor")
End Using

輸入形態操作

膨脹

加厚圖像中的字元，這有助於連接文字中的斷線，提高對淡或細字體的識別。

瞭解如何使用:使用濾鏡修正圖像以供閱讀

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply Dilate filter
imageInput.Dilate();

// Export filtered image
imageInput.SaveAsImages("dilate.jpg");

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply Dilate filter
imageInput.Dilate();

// Export filtered image
imageInput.SaveAsImages("dilate.jpg");

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput As New OcrImageInput("sample.jpg")

    ' Apply Dilate filter
    imageInput.Dilate()

    ' Export filtered image
    imageInput.SaveAsImages("dilate.jpg")
End Using

侵蝕

削弱圖像中的字元，這對分隔接觸或混合的字元很有用。

瞭解如何使用:使用濾鏡修正圖像以供閱讀

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply Erode filter
imageInput.Erode();

// Export filtered image
imageInput.SaveAsImages("erode.jpg");

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply Erode filter
imageInput.Erode();

// Export filtered image
imageInput.SaveAsImages("erode.jpg");

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput As New OcrImageInput("sample.jpg")

    ' Apply Erode filter
    imageInput.Erode()

    ' Export filtered image
    imageInput.SaveAsImages("erode.jpg")
End Using

更改像素顏色

替換圖像中的特定顏色范圍，使您可以在OCR之前去除水印、彩色背景或其他分心元素。

瞭解如何使用:修正.NET C#中的閱讀圖像顏色

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");
IronSoftware.Drawing.Color currentColor = new IronSoftware.Drawing.Color("#DB645C");
IronSoftware.Drawing.Color newColor = IronSoftware.Drawing.Color.DarkCyan;

// Replace color
imageInput.ReplaceColor(currentColor, newColor, 80);

// Export the modified image
imageInput.SaveAsImages("replaceColor");

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");
IronSoftware.Drawing.Color currentColor = new IronSoftware.Drawing.Color("#DB645C");
IronSoftware.Drawing.Color newColor = IronSoftware.Drawing.Color.DarkCyan;

// Replace color
imageInput.ReplaceColor(currentColor, newColor, 80);

// Export the modified image
imageInput.SaveAsImages("replaceColor");

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput As New OcrImageInput("sample.jpg")
    Dim currentColor As New IronSoftware.Drawing.Color("#DB645C")
    Dim newColor As IronSoftware.Drawing.Color = IronSoftware.Drawing.Color.DarkCyan

    ' Replace color
    imageInput.ReplaceColor(currentColor, newColor, 80)

    ' Export the modified image
    imageInput.SaveAsImages("replaceColor")
End Using

輸入方向操作

去傾斜

自動檢測和拉直傾斜或歪斜的圖像，極大地提高了對不完美掃描的OCR準確率。

瞭解如何使用:修正.NET C#中的閱讀圖像方向

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("paragraph_skewed.png");

// Apply Deskew filter
imageInput.Deskew();

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("paragraph_skewed.png");

// Apply Deskew filter
imageInput.Deskew();

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput As New OcrImageInput("paragraph_skewed.png")
    ' Apply Deskew filter
    imageInput.Deskew()
End Using

旋轉

以任何角度程式化旋轉圖像，以確保文字正確定向供OCR引擎使用。

瞭解如何使用:修正.NET C#中的閱讀圖像方向

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("paragraph_skewed.png");

// Rotate the image 180 degrees clockwise
imageInput.Rotate(180);

// Export the modified image
imageInput.SaveAsImages("rotate");

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("paragraph_skewed.png");

// Rotate the image 180 degrees clockwise
imageInput.Rotate(180);

// Export the modified image
imageInput.SaveAsImages("rotate");

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput = New OcrImageInput("paragraph_skewed.png")

    ' Rotate the image 180 degrees clockwise
    imageInput.Rotate(180)

    ' Export the modified image
    imageInput.SaveAsImages("rotate")
End Using

檢測方向

自動確定頁面方向（0、90、180、270度），這在OCR之前的方向矯正中很有用。即使文件是上下顛倒掃描的，也能保證高精度。

瞭解如何使用:檢測頁面旋轉

using IronOcr;

using var input = new OcrInput();

// Load PDF document
input.LoadPdf("Clockwise90.pdf");

// Detect page rotation
var results = input.DetectPageOrientation();

// Ouput result
foreach(var result in results)
{
    Console.WriteLine(result.PageNumber);
    Console.WriteLine(result.HighConfidence);
    Console.WriteLine(result.RotationAngle);
}

using IronOcr;

using var input = new OcrInput();

// Load PDF document
input.LoadPdf("Clockwise90.pdf");

// Detect page rotation
var results = input.DetectPageOrientation();

// Ouput result
foreach(var result in results)
{
    Console.WriteLine(result.PageNumber);
    Console.WriteLine(result.HighConfidence);
    Console.WriteLine(result.RotationAngle);
}

Imports IronOcr

Dim Input As New OcrInput()

' Load PDF document
Input.LoadPdf("Clockwise90.pdf")

' Detect page rotation
Dim Results = Input.DetectPageOrientation()

' Output result
For Each Result In Results
    Console.WriteLine(Result.PageNumber)
    Console.WriteLine(Result.HighConfidence)
    Console.WriteLine(Result.RotationAngle)
Next

輸入解析度控制

比例

將圖像重新設置為OCR的最佳解析度，顯著提高低解析度原始文件的準確性。

瞭解如何使用:修正.NET C#中的閱讀圖像方向

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("paragraph_skewed.png");

// Apply scale
imageInput.Scale(70);

// Export the modified image
imageInput.SaveAsImages("rotate");

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("paragraph_skewed.png");

// Apply scale
imageInput.Scale(70);

// Export the modified image
imageInput.SaveAsImages("rotate");

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput As New OcrImageInput("paragraph_skewed.png")
    ' Apply scale
    imageInput.Scale(70)

    ' Export the modified image
    imageInput.SaveAsImages("rotate")
End Using

DPI設置

手動設置低解析圖像或缺少元資料的掃描的每英寸點數（DPI）。提供DPI值可引導OCR引擎，顯著提高識別質量。

瞭解如何使用:C# Tesseract圖像DPI

using IronOcr;
using System;

var ocrTesseract = new IronTesseract();
using var ocrInput = new OcrInput();
ocrInput.TargetDPI = 300;
ocrInput.LoadImage(@"images\image.png");
var ocrResult = ocrTesseract.Read(ocrInput);
Console.WriteLine(ocrResult.Text);

using IronOcr;
using System;

var ocrTesseract = new IronTesseract();
using var ocrInput = new OcrInput();
ocrInput.TargetDPI = 300;
ocrInput.LoadImage(@"images\image.png");
var ocrResult = ocrTesseract.Read(ocrInput);
Console.WriteLine(ocrResult.Text);

Imports IronOcr
Imports System

Dim ocrTesseract = New IronTesseract()
Using ocrInput = New OcrInput()
    ocrInput.TargetDPI = 300
    ocrInput.LoadImage("images\image.png")
    Dim ocrResult = ocrTesseract.Read(ocrInput)
    Console.WriteLine(ocrResult.Text)
End Using

增強解析度

通過算法有效提高低解析度圖像的清晰度和清晰度，以從模糊或像素化的輸入中恢復文字。

瞭解如何使用:使用濾鏡修正圖像以供閱讀

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply enhance resolution filter
imageInput.EnhanceResolution();

// Export filtered image
imageInput.SaveAsImages("sharpen.jpg");

using IronOcr;

// Instantiate IronTesseract
IronTesseract ocrTesseract = new IronTesseract();

// Add image
using var imageInput = new OcrImageInput("sample.jpg");

// Apply enhance resolution filter
imageInput.EnhanceResolution();

// Export filtered image
imageInput.SaveAsImages("sharpen.jpg");

Imports IronOcr

' Instantiate IronTesseract
Dim ocrTesseract As New IronTesseract()

' Add image
Using imageInput As New OcrImageInput("sample.jpg")
    ' Apply enhance resolution filter
    imageInput.EnhanceResolution()
    
    ' Export filtered image
    imageInput.SaveAsImages("sharpen.jpg")
End Using

濾鏡嚮導

使用一個智能方法應用預處理濾鏡的精選鏈。濾鏡向導會自動分析輸入圖像並應用最佳的更正序列以達到最佳的OCR結果。

瞭解如何使用:濾鏡嚮導

using IronOcr;

var ocrTesseract = new IronTesseract();

// WIZARD - If you are unsure which filters to use,
// use the debug-wizard to test all combinations:
string codeToRun = OcrInputFilterWizard.Run(@"images\image.png", out double confidence, ocrTesseract);
Console.WriteLine($"Confidence: {confidence}");
Console.WriteLine(codeToRun);

using IronOcr;

var ocrTesseract = new IronTesseract();

// WIZARD - If you are unsure which filters to use,
// use the debug-wizard to test all combinations:
string codeToRun = OcrInputFilterWizard.Run(@"images\image.png", out double confidence, ocrTesseract);
Console.WriteLine($"Confidence: {confidence}");
Console.WriteLine(codeToRun);

Imports IronOcr

Dim ocrTesseract = New IronTesseract()

' WIZARD - If you are unsure which filters to use,
' use the debug-wizard to test all combinations:
Dim confidence As Double
Dim codeToRun As String = OcrInputFilterWizard.Run("images\image.png", confidence, ocrTesseract)
Console.WriteLine($"Confidence: {confidence}")
Console.WriteLine(codeToRun)

OCR 圖像區域

通過僅針對包含文字的圖像的特定區域來節省處理時間。只需定義一個矩形區域即可從表單、表格或雜亂背景中隔離並提取文字。

瞭解如何使用:在C#中指定圖像區域的Tesseract OCR

using IronOcr;
using IronSoftware.Drawing;

var ocrTesseract = new IronTesseract();
using var ocrInput = new OcrInput();
var ContentArea = new Rectangle(x: 215, y: 1250, width: 1335, height: 280);
ocrInput.LoadImage("img/example.png", ContentArea);
var ocrResult = ocrTesseract.Read(ocrInput);
Console.WriteLine(ocrResult.Text);

using IronOcr;
using IronSoftware.Drawing;

var ocrTesseract = new IronTesseract();
using var ocrInput = new OcrInput();
var ContentArea = new Rectangle(x: 215, y: 1250, width: 1335, height: 280);
ocrInput.LoadImage("img/example.png", ContentArea);
var ocrResult = ocrTesseract.Read(ocrInput);
Console.WriteLine(ocrResult.Text);

Imports IronOcr
Imports IronSoftware.Drawing

Dim ocrTesseract = New IronTesseract()
Using ocrInput = New OcrInput()
    Dim ContentArea = New Rectangle(x:=215, y:=1250, width:=1335, height:=280)
    ocrInput.LoadImage("img/example.png", ContentArea)
    Dim ocrResult = ocrTesseract.Read(ocrInput)
    Console.WriteLine(ocrResult.Text)
End Using