public static WordList DoOCR(string pdf_filename, int page_number)
{
Logging.Info("+Rendering page {1} for PDF file {0}", pdf_filename, page_number);
// Do the OCR on each of the rectangles
WordList word_list = new WordList();
word_list.AddRange(ConvertToWordList());
Logging.Info("-Doing OCR");
Logging.Info("Faked {0} words ({1} @ #{2})", word_list.Count, pdf_filename, page_number);
#if false
Logging.Info("+Reordering words for columns");
WordList word_list_ordered = ColumnWordOrderer.ReorderWords(word_list);
Logging.Info("-Reordering words for columns");
word_list_ordered.WriteToFile(ocr_output_filename);
#endif
return(word_list);
}
public static ExtractionResult ExtractText(PDFRenderer pdf_renderer)
{
Logging.Info("Doing text extraction for {0}", pdf_renderer.ToString());
try
{
int page_count = pdf_renderer.PageCount;
PageDetail[] page_details = new PageDetail[page_count];
for (int i = 0; i < page_count; ++i)
{
page_details[i] = new PageDetail(i + 1);
}
bool all_pages_already_with_ocr = true;
foreach (PageDetail page_detail in page_details)
{
WordList word_list = pdf_renderer.GetOCRText(page_detail.page);
if (null != word_list)
{
Logging.Debug特("Page {0} has OCR available ({1})", page_detail.page, pdf_renderer.DocumentFingerprint);
}
else
{
Logging.Debug特("Page {0} has not had OCR done ({1})", page_detail.page, pdf_renderer.DocumentFingerprint);
all_pages_already_with_ocr = false;
}
}
if (!all_pages_already_with_ocr)
{
Logging.Info("Not all pages are ready with OCR");
return(new ExtractionResult(ExtractionResult.ResultType.OCR_NOT_COMPLETE));
}
// All pages OCR are complete, so load the words lists
foreach (PageDetail page_detail in page_details)
{
page_detail.word_list = pdf_renderer.GetOCRText(page_detail.page);
}
// Order the words on each page in a manner that makes sense of multiple columns
List <Word> words_ordered = new List <Word>();
foreach (PageDetail page_detail in page_details)
{
WordList words_ordered_for_page = ColumnWordOrderer.ReorderWords(page_detail.word_list);
words_ordered.AddRange(words_ordered_for_page);
}
// Concatenate the words
List <string> words = new List <string>();
foreach (Word word in words_ordered)
{
words.Add(word.Text);
}
// Kill some of the line-wrapping hyphenation
for (int i = words.Count - 2; i >= 0; --i)
{
if (words[i].EndsWith("-"))
{
words[i] = words[i].Substring(0, words[i].Length - 1) + words[i + 1];
words.RemoveAt(i + 1);
}
}
// Return the words
Logging.Info("Successfully extracted {0} words: {1}", words.Count, ArrayFormatter.listElements(words));
return(new ExtractionResult(ExtractionResult.ResultType.SUCCESS, words));
}
catch (Exception ex)
{
Logging.Warn(ex, "There was an exception while extracting coherent text");
return(new ExtractionResult(ExtractionResult.ResultType.EXCEPTION, ex));
}
}
public static WordList DoOCR(string pdf_filename, int page_number)
{
Logging.Info("+Rendering page {1} for PDF file {0}", pdf_filename, page_number);
using (MemoryStream ms = new MemoryStream(SoraxPDFRenderer.GetPageByDPIAsImage(pdf_filename, pdf_user_password, page_number, 200)))
{
Bitmap bitmap = (Bitmap)Image.FromStream(ms);
Logging.Info("-Rendering page #{0}", page_number);
Logging.Info("Startup directory is {0}", Environment.CurrentDirectory);
Logging.Info("Language is '{0}'", language);
using (Tesseract ocr = new Tesseract())
{
ocr.Init(null, language, false);
Logging.Info("+Doing OCR");
const int MIN_WIDTH = 0;
// Build a list of all the rectangles to process
PDFRegionLocator pdf_region_locator = new PDFRegionLocator(bitmap);
PDFRegionLocator.Region last_region = pdf_region_locator.regions[0];
List <Rectangle> rectangles = new List <Rectangle>();
Rectangle last_rectangle = new Rectangle();
foreach (PDFRegionLocator.Region region in pdf_region_locator.regions)
{
int rect_height = region.y - last_region.y;
bool alarming_height = (rect_height <= 0);
Rectangle rectangle = new Rectangle();
if (last_region.state == PDFRegionLocator.SegmentState.BLANKS)
{
// LHS
{
rectangle = new Rectangle(0, last_region.y, bitmap.Width / 2, Math.Max(MIN_WIDTH, rect_height));
}
// RHS
{
rectangle = new Rectangle(bitmap.Width / 2, last_region.y, bitmap.Width / 2, Math.Max(MIN_WIDTH, rect_height));
}
}
else if (last_region.state == PDFRegionLocator.SegmentState.PIXELS)
{
// Full column
{
rectangle = new Rectangle(0, last_region.y, bitmap.Width, Math.Max(MIN_WIDTH, rect_height));
}
}
if (alarming_height || rectangle.Height <= 0)
{
Logging.Warn("Calculated region height is negative or zero: {0} :: Calculated region {1} <-- CURRENT:{2} - LAST:{3}", rect_height, rectangle, region, last_region);
// skip rectangle
}
else if (last_rectangle.X == rectangle.X && last_rectangle.Y == rectangle.Y)
{
Logging.Warn("Overlapping subsequent rectangles will be merged :: CURRENT:{0} - LAST:{1}", rectangle, last_rectangle);
last_rectangle.Width = Math.Max(last_rectangle.Width, rectangle.Width);
last_rectangle.Height = Math.Max(last_rectangle.Height, rectangle.Height);
Logging.Warn("--> Updated 'last' rectangle:{0}", last_rectangle);
}
else
{
rectangles.Add(rectangle);
last_rectangle = rectangle;
}
last_region = region;
}
// DEBUG CODE: Draw in the region rectangles
//
// When we run in NOKILL mode, we "know" we're running in a debugger or stand-alone environment
// intended for testing this code. Hence we should dump the regions image as part of the process.
if (no_kill)
{
string bitmap_diag_path = pdf_filename + @"." + page_number + @"-ocr.png";
Logging.Info("Dumping regions-augmented page {0} PNG image to file {1}", page_number, bitmap_diag_path);
Graphics g = Graphics.FromImage(bitmap);
foreach (Rectangle rectangle in rectangles)
{
if (rectangle.Width <= MIN_WIDTH && rectangle.Height > MIN_WIDTH)
{
DrawRectangleOutline(g, Pens.Purple, rectangle);
}
else if (rectangle.Width > MIN_WIDTH && rectangle.Height <= MIN_WIDTH)
{
DrawRectangleOutline(g, Pens.PowderBlue, rectangle);
}
else if (rectangle.Width <= MIN_WIDTH && rectangle.Height <= MIN_WIDTH)
{
DrawRectangleOutline(g, Pens.Red, rectangle);
}
else
{
DrawRectangleOutline(g, Pens.LawnGreen, rectangle);
}
}
bitmap.Save(bitmap_diag_path, ImageFormat.Png);
}
// Do the OCR on each of the rectangles
WordList word_list = new WordList();
foreach (Rectangle rectangle in rectangles)
{
if (0 == rectangle.Width || 0 == rectangle.Height)
{
Logging.Info("Skipping zero extent rectangle {0}", rectangle.ToString());
continue;
}
Logging.Info("Doing OCR for region {0} on bitmap WxH: {1}x{2}", rectangle.ToString(), bitmap.Width, bitmap.Height);
List <Word> result = ocr.DoOCR(bitmap, rectangle);
Logging.Info("Got {0} words", result.Count);
word_list.AddRange(ConvertToWordList(result, rectangle, bitmap));
}
Logging.Info("-Doing OCR");
Logging.Info("Found {0} words ({1} @ #{2})", word_list.Count, pdf_filename, page_number);
#if false
Logging.Info("+Reordering words for columns");
WordList word_list_ordered = ColumnWordOrderer.ReorderWords(word_list);
Logging.Info("-Reordering words for columns");
word_list_ordered.WriteToFile(ocr_output_filename);
#endif
return(word_list);
}
}
}
