在 IronOCR 中減少輸出 PDF 的檔案大小
如何在IronOCR中減小輸出PDF的文件大小?
IronOCR將自動放大被檢測為低質量的輸入 (低於150DPI) 以確保準確的讀取結果。
如果檢測到DPI低於150,TargetDPI (預設 225DPI) 定義了PDF的渲染DPI - 這與手動設置TargetDPI = 225\相同。
為了減少輸出文件的大小,你可以設置較低的TargetDPI,這樣會生成較小的PDF,但設置太低可能會影響OCR性能。一切需要平衡。
建議的值是96, 72, 48
// how to reduce and usage by by reducing DPI
//Example 1
using IronOcr;
var Ocr = new IronTesseract();
using (var Input = new OcrInput())
{
Input.TargetDPI = 96; // DPI of output, default is 225
Input.AddPdf("example.pdf", "password");
var Result = Ocr.Read(Input);
Console.WriteLine(Result.Text);
}
//Example 2
var ocr = new IronTesseract();
using (var ocrInput = new OcrInput())
{
ocrInput.AddPdf("img/Input.pdf", 72); //TargetDPI
var ocrResult = ocr.Read(ocrInput);
ocrResult.SaveAsSearchablePdf(@"Output.pdf");
}
// how to reduce and usage by by reducing DPI
//Example 1
using IronOcr;
var Ocr = new IronTesseract();
using (var Input = new OcrInput())
{
Input.TargetDPI = 96; // DPI of output, default is 225
Input.AddPdf("example.pdf", "password");
var Result = Ocr.Read(Input);
Console.WriteLine(Result.Text);
}
//Example 2
var ocr = new IronTesseract();
using (var ocrInput = new OcrInput())
{
ocrInput.AddPdf("img/Input.pdf", 72); //TargetDPI
var ocrResult = ocr.Read(ocrInput);
ocrResult.SaveAsSearchablePdf(@"Output.pdf");
}
' how to reduce and usage by by reducing DPI
'Example 1
Imports IronOcr
Private Ocr = New IronTesseract()
Using Input = New OcrInput()
Input.TargetDPI = 96 ' DPI of output, default is 225
Input.AddPdf("example.pdf", "password")
Dim Result = Ocr.Read(Input)
Console.WriteLine(Result.Text)
End Using
'Example 2
Dim ocr = New IronTesseract()
Using ocrInput As New OcrInput()
ocrInput.AddPdf("img/Input.pdf", 72) 'TargetDPI
Dim ocrResult = ocr.Read(ocrInput)
ocrResult.SaveAsSearchablePdf("Output.pdf")
End Using
若要禁用自動放大功能,請使用 TargetDPI = 0
。這將忽略 TargetDPI 值,並按原樣讀取輸入文件。
請參閱 API 以獲取更多信息: https://ironsoftware.com/csharp/ocr/object-reference/api/IronOcr.OcrInput.html?q=targetdpi#IronOcr_OcrInput_TargetDPI