/// <summary>Performs basic image preprocessing using buffered image (if provided).</summary>
/// <remarks>
/// Performs basic image preprocessing using buffered image (if provided).
/// Preprocessed image will be saved in temporary directory.
/// </remarks>
/// <param name="inputFile">
/// input image
/// <see cref="System.IO.FileInfo"/>
/// </param>
/// <param name="pageNumber">number of page to be preprocessed</param>
/// <returns>
/// created preprocessed image as
/// <see cref="Tesseract.Pix"/>
/// </returns>
internal static Pix PreprocessImage(FileInfo inputFile, int pageNumber)
{
Pix pix = null;
// read image
if (IsTiffImage(inputFile))
{
pix = TesseractOcrUtil.ReadPixPageFromTiff(inputFile, pageNumber - 1);
}
else
{
pix = ReadPix(inputFile);
}
if (pix == null)
{
throw new Tesseract4OcrException(Tesseract4OcrException.CANNOT_READ_PROVIDED_IMAGE).SetMessageParams(inputFile
.FullName);
}
return(TesseractOcrUtil.PreprocessPix(pix));
}