tesseract  4.0.0-1-g2a2b
tesseract::TessResultRenderer Class Referenceabstract

#include <renderer.h>

Inheritance diagram for tesseract::TessResultRenderer:
tesseract::TessBoxTextRenderer tesseract::TessHOcrRenderer tesseract::TessOsdRenderer tesseract::TessPDFRenderer tesseract::TessTextRenderer tesseract::TessTsvRenderer tesseract::TessUnlvRenderer

Public Member Functions

virtual ~TessResultRenderer ()
 
void insert (TessResultRenderer *next)
 
TessResultRenderernext ()
 
bool BeginDocument (const char *title)
 
bool AddImage (TessBaseAPI *api)
 
bool EndDocument ()
 
const char * file_extension () const
 
const char * title () const
 
bool happy ()
 
int imagenum () const
 

Protected Member Functions

 TessResultRenderer (const char *outputbase, const char *extension)
 
virtual bool BeginDocumentHandler ()
 
virtual bool AddImageHandler (TessBaseAPI *api)=0
 
virtual bool EndDocumentHandler ()
 
void AppendString (const char *s)
 
void AppendData (const char *s, int len)
 

Detailed Description

Interface for rendering tesseract results into a document, such as text, HOCR or pdf. This class is abstract. Specific classes handle individual formats. This interface is then used to inject the renderer class into tesseract when processing images.

For simplicity implementing this with tesesract version 3.01, the renderer contains document state that is cleared from document to document just as the TessBaseAPI is. This way the base API can just delegate its rendering functionality to injected renderers, and the renderers can manage the associated state needed for the specific formats in addition to the heuristics for producing it.

Definition at line 45 of file renderer.h.

Constructor & Destructor Documentation

◆ ~TessResultRenderer()

tesseract::TessResultRenderer::~TessResultRenderer ( )
virtual

Definition at line 49 of file renderer.cpp.

49  {
50  if (fout_ != nullptr) {
51  if (fout_ != stdout)
52  fclose(fout_);
53  else
54  clearerr(fout_);
55  }
56  delete next_;
57 }

◆ TessResultRenderer()

tesseract::TessResultRenderer::TessResultRenderer ( const char *  outputbase,
const char *  extension 
)
protected

Called by concrete classes.

outputbase is the name of the output file excluding extension. For example, "/path/to/chocolate-chip-cookie-recipe"

extension indicates the file extension to be used for output files. For example "pdf" will produce a .pdf file, and "hocr" will produce .hocr files.

Definition at line 33 of file renderer.cpp.

35  : file_extension_(extension),
36  title_(""), imagenum_(-1),
37  fout_(stdout),
38  next_(nullptr),
39  happy_(true) {
40  if (strcmp(outputbase, "-") && strcmp(outputbase, "stdout")) {
41  STRING outfile = STRING(outputbase) + STRING(".") + STRING(file_extension_);
42  fout_ = fopen(outfile.string(), "wb");
43  if (fout_ == nullptr) {
44  happy_ = false;
45  }
46  }
47 }
const char * string() const
Definition: strngs.cpp:196
Definition: strngs.h:45

Member Function Documentation

◆ AddImage()

bool tesseract::TessResultRenderer::AddImage ( TessBaseAPI api)

Adds the recognized text from the source image to the current document. Invalid if BeginDocument not yet called.

Note that this API is a bit weird but is designed to fit into the current TessBaseAPI implementation where the api has lots of state information that we might want to add in.

Definition at line 83 of file renderer.cpp.

83  {
84  if (!happy_) return false;
85  ++imagenum_;
86  bool ok = AddImageHandler(api);
87  if (next_) {
88  ok = next_->AddImage(api) && ok;
89  }
90  return ok;
91 }
virtual bool AddImageHandler(TessBaseAPI *api)=0
bool AddImage(TessBaseAPI *api)
Definition: renderer.cpp:83

◆ AddImageHandler()

◆ AppendData()

void tesseract::TessResultRenderer::AppendData ( const char *  s,
int  len 
)
protected

Definition at line 106 of file renderer.cpp.

106  {
107  if (!tesseract::Serialize(fout_, s, len)) happy_ = false;
108 }
bool Serialize(FILE *fp, const char *data, size_t n)
Definition: serialis.cpp:59

◆ AppendString()

void tesseract::TessResultRenderer::AppendString ( const char *  s)
protected

Definition at line 102 of file renderer.cpp.

102  {
103  AppendData(s, strlen(s));
104 }
void AppendData(const char *s, int len)
Definition: renderer.cpp:106

◆ BeginDocument()

bool tesseract::TessResultRenderer::BeginDocument ( const char *  title)

Starts a new document with the given title. This clears the contents of the output data. Title should use UTF-8 encoding.

Definition at line 72 of file renderer.cpp.

72  {
73  if (!happy_) return false;
74  title_ = title;
75  imagenum_ = -1;
76  bool ok = BeginDocumentHandler();
77  if (next_) {
78  ok = next_->BeginDocument(title) && ok;
79  }
80  return ok;
81 }
bool BeginDocument(const char *title)
Definition: renderer.cpp:72
const char * title() const
Definition: renderer.h:81
virtual bool BeginDocumentHandler()
Definition: renderer.cpp:110

◆ BeginDocumentHandler()

bool tesseract::TessResultRenderer::BeginDocumentHandler ( )
protectedvirtual

Reimplemented in tesseract::TessPDFRenderer, tesseract::TessTsvRenderer, and tesseract::TessHOcrRenderer.

Definition at line 110 of file renderer.cpp.

110  {
111  return happy_;
112 }

◆ EndDocument()

bool tesseract::TessResultRenderer::EndDocument ( )

Finishes the document and finalizes the output data Invalid if BeginDocument not yet called.

Definition at line 93 of file renderer.cpp.

93  {
94  if (!happy_) return false;
95  bool ok = EndDocumentHandler();
96  if (next_) {
97  ok = next_->EndDocument() && ok;
98  }
99  return ok;
100 }
virtual bool EndDocumentHandler()
Definition: renderer.cpp:114

◆ EndDocumentHandler()

bool tesseract::TessResultRenderer::EndDocumentHandler ( )
protectedvirtual

Reimplemented in tesseract::TessPDFRenderer, tesseract::TessTsvRenderer, and tesseract::TessHOcrRenderer.

Definition at line 114 of file renderer.cpp.

114  {
115  return happy_;
116 }

◆ file_extension()

const char* tesseract::TessResultRenderer::file_extension ( ) const
inline

Definition at line 80 of file renderer.h.

80 { return file_extension_; }

◆ happy()

bool tesseract::TessResultRenderer::happy ( )
inline

Definition at line 84 of file renderer.h.

84 { return happy_; }

◆ imagenum()

int tesseract::TessResultRenderer::imagenum ( ) const
inline

Returns the index of the last image given to AddImage (i.e. images are incremented whether the image succeeded or not)

This is always defined. It means either the number of the current image, the last image ended, or in the completed document depending on when in the document lifecycle you are looking at it. Will return -1 if a document was never started.

Definition at line 95 of file renderer.h.

95 { return imagenum_; }

◆ insert()

void tesseract::TessResultRenderer::insert ( TessResultRenderer next)

Definition at line 59 of file renderer.cpp.

59  {
60  if (next == nullptr) return;
61 
62  TessResultRenderer* remainder = next_;
63  next_ = next;
64  if (remainder) {
65  while (next->next_ != nullptr) {
66  next = next->next_;
67  }
68  next->next_ = remainder;
69  }
70 }
TessResultRenderer * next()
Definition: renderer.h:55
struct TessResultRenderer TessResultRenderer
Definition: capi.h:83

◆ next()

TessResultRenderer* tesseract::TessResultRenderer::next ( )
inline

Definition at line 55 of file renderer.h.

55 { return next_; }

◆ title()

const char* tesseract::TessResultRenderer::title ( ) const
inline

Definition at line 81 of file renderer.h.

81 { return title_.c_str(); }
const char * c_str() const
Definition: strngs.cpp:207

The documentation for this class was generated from the following files: