/// <summary>
/// Reads data from the provided input image file and returns retrieved
/// data as string.
/// </summary>
/// <param name="input">
/// input image
/// <see cref="System.IO.FileInfo"/>
/// </param>
/// <param name="outputFormat">
/// return
/// <see cref="OutputFormat"/>
/// result
/// </param>
/// <returns>
/// OCR result as a
/// <see cref="System.String"/>
/// that is
/// returned after processing the given image
/// </returns>
public String DoImageOcr(FileInfo input, OutputFormat outputFormat)
{
String result = "";
VerifyImageFormatValidity(input);
AbstractTesseract4OcrEngine.ITesseractOcrResult processedData = ProcessInputFiles(input, outputFormat);
if (processedData != null)
{
if (outputFormat.Equals(OutputFormat.TXT))
{
result = ((AbstractTesseract4OcrEngine.StringTesseractOcrResult)processedData).GetData();
}
else
{
StringBuilder outputText = new StringBuilder();
IDictionary <int, IList <TextInfo> > outputMap = ((AbstractTesseract4OcrEngine.TextInfoTesseractOcrResult)processedData
).GetTextInfos();
foreach (int page in outputMap.Keys)
{
StringBuilder pageText = new StringBuilder();
foreach (TextInfo textInfo in outputMap.Get(page))
{
pageText.Append(textInfo.GetText());
pageText.Append(Environment.NewLine);
}
outputText.Append(pageText);
outputText.Append(Environment.NewLine);
}
result = outputText.ToString();
}
}
return(result);
}
/// <summary>Reads data from the provided input image file.</summary>
/// <param name="input">
/// input image
/// <see cref="System.IO.FileInfo"/>
/// </param>
/// <param name="outputFormat">
///
/// <see cref="OutputFormat"/>
/// for the result returned
/// by
/// <see cref="iText.Pdfocr.IOcrEngine"/>
/// </param>
/// <returns>
///
/// <see cref="ITesseractOcrResult"/>
/// instance, either
/// <see cref="StringTesseractOcrResult"/>
/// if output format is TXT, or
/// <see cref="TextInfoTesseractOcrResult"/>
/// if the output format is HOCR
/// </returns>
private AbstractTesseract4OcrEngine.ITesseractOcrResult ProcessInputFiles(FileInfo input, OutputFormat outputFormat
)
{
IDictionary <int, IList <TextInfo> > imageData = new LinkedDictionary <int, IList <TextInfo> >();
StringBuilder data = new StringBuilder();
IList <FileInfo> tempFiles = new List <FileInfo>();
AbstractTesseract4OcrEngine.ITesseractOcrResult result = null;
try {
// image needs to be paginated only if it's tiff
// or preprocessing isn't required
int realNumOfPages = !ImagePreprocessingUtil.IsTiffImage(input) ? 1 : ImagePreprocessingUtil.GetNumberOfPageTiff
(input);
int numOfPages = GetTesseract4OcrEngineProperties().IsPreprocessingImages() ? realNumOfPages : 1;
int numOfFiles = GetTesseract4OcrEngineProperties().IsPreprocessingImages() ? 1 : realNumOfPages;
for (int page = 1; page <= numOfPages; page++)
{
String extension = outputFormat.Equals(OutputFormat.HOCR) ? ".hocr" : ".txt";
for (int i = 0; i < numOfFiles; i++)
{
tempFiles.Add(CreateTempFile(extension));
}
DoTesseractOcr(input, tempFiles, outputFormat, page);
if (outputFormat.Equals(OutputFormat.HOCR))
{
IDictionary <int, IList <TextInfo> > pageData = TesseractHelper.ParseHocrFile(tempFiles, GetTesseract4OcrEngineProperties
().GetTextPositioning());
if (GetTesseract4OcrEngineProperties().IsPreprocessingImages())
{
imageData.Put(page, pageData.Get(1));
}
else
{
imageData = pageData;
}
result = new AbstractTesseract4OcrEngine.TextInfoTesseractOcrResult(imageData);
}
else
{
foreach (FileInfo tmpFile in tempFiles)
{
if (File.Exists(System.IO.Path.Combine(tmpFile.FullName)))
{
data.Append(TesseractHelper.ReadTxtFile(tmpFile));
}
}
result = new AbstractTesseract4OcrEngine.StringTesseractOcrResult(data.ToString());
}
}
}
catch (System.IO.IOException e) {
LogManager.GetLogger(GetType()).Error(MessageFormatUtil.Format(Tesseract4LogMessageConstant.CANNOT_OCR_INPUT_FILE
, e.Message));
}
finally {
foreach (FileInfo file in tempFiles)
{
TesseractHelper.DeleteFile(file.FullName);
}
}
return(result);
}
