tesseract/cube/char_samp.cpp
theraysmith@gmail.com e6e6c35ee1 Fixed issue 1114
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@1073 d0cd1f9f-072b-0410-8dd7-cf729c803f20
2014-04-24 00:46:11 +00:00

670 lines
20 KiB
C++

/**********************************************************************
* File: char_samp.cpp
* Description: Implementation of a Character Bitmap Sample Class
* Author: Ahmad Abdulkader
* Created: 2007
*
* (C) Copyright 2008, Google Inc.
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
** http://www.apache.org/licenses/LICENSE-2.0
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*
**********************************************************************/
#include <string.h>
#include <string>
#include "char_samp.h"
#include "cube_utils.h"
namespace tesseract {
#define MAX_LINE_LEN 1024
CharSamp::CharSamp()
: Bmp8(0, 0) {
left_ = 0;
top_ = 0;
label32_ = NULL;
page_ = -1;
}
CharSamp::CharSamp(int wid, int hgt)
: Bmp8(wid, hgt) {
left_ = 0;
top_ = 0;
label32_ = NULL;
page_ = -1;
}
CharSamp::CharSamp(int left, int top, int wid, int hgt)
: Bmp8(wid, hgt)
, left_(left)
, top_(top) {
label32_ = NULL;
page_ = -1;
}
CharSamp::~CharSamp() {
if (label32_ != NULL) {
delete []label32_;
label32_ = NULL;
}
}
// returns a UTF-8 version of the string label
string CharSamp::stringLabel() const {
string str = "";
if (label32_ != NULL) {
string_32 str32(label32_);
CubeUtils::UTF32ToUTF8(str32.c_str(), &str);
}
return str;
}
// set a the string label using a UTF encoded string
void CharSamp::SetLabel(string str) {
if (label32_ != NULL) {
delete []label32_;
label32_ = NULL;
}
string_32 str32;
CubeUtils::UTF8ToUTF32(str.c_str(), &str32);
SetLabel(reinterpret_cast<const char_32 *>(str32.c_str()));
}
// creates a CharSamp object from file
CharSamp *CharSamp::FromCharDumpFile(CachedFile *fp) {
unsigned short left;
unsigned short top;
unsigned short page;
unsigned short first_char;
unsigned short last_char;
unsigned short norm_top;
unsigned short norm_bottom;
unsigned short norm_aspect_ratio;
unsigned int val32;
char_32 *label32;
// read and check 32 bit marker
if (fp->Read(&val32, sizeof(val32)) != sizeof(val32)) {
return NULL;
}
if (val32 != 0xabd0fefe) {
return NULL;
}
// read label length,
if (fp->Read(&val32, sizeof(val32)) != sizeof(val32)) {
return NULL;
}
// the label is not null terminated in the file
if (val32 > 0 && val32 < MAX_UINT32) {
label32 = new char_32[val32 + 1];
if (label32 == NULL) {
return NULL;
}
// read label
if (fp->Read(label32, val32 * sizeof(*label32)) !=
(val32 * sizeof(*label32))) {
return NULL;
}
// null terminate
label32[val32] = 0;
} else {
label32 = NULL;
}
// read coordinates
if (fp->Read(&page, sizeof(page)) != sizeof(page)) {
return NULL;
}
if (fp->Read(&left, sizeof(left)) != sizeof(left)) {
return NULL;
}
if (fp->Read(&top, sizeof(top)) != sizeof(top)) {
return NULL;
}
if (fp->Read(&first_char, sizeof(first_char)) != sizeof(first_char)) {
return NULL;
}
if (fp->Read(&last_char, sizeof(last_char)) != sizeof(last_char)) {
return NULL;
}
if (fp->Read(&norm_top, sizeof(norm_top)) != sizeof(norm_top)) {
return NULL;
}
if (fp->Read(&norm_bottom, sizeof(norm_bottom)) != sizeof(norm_bottom)) {
return NULL;
}
if (fp->Read(&norm_aspect_ratio, sizeof(norm_aspect_ratio)) !=
sizeof(norm_aspect_ratio)) {
return NULL;
}
// create the object
CharSamp *char_samp = new CharSamp();
if (char_samp == NULL) {
return NULL;
}
// init
char_samp->label32_ = label32;
char_samp->page_ = page;
char_samp->left_ = left;
char_samp->top_ = top;
char_samp->first_char_ = first_char;
char_samp->last_char_ = last_char;
char_samp->norm_top_ = norm_top;
char_samp->norm_bottom_ = norm_bottom;
char_samp->norm_aspect_ratio_ = norm_aspect_ratio;
// load the Bmp8 part
if (char_samp->LoadFromCharDumpFile(fp) == false) {
delete char_samp;
return NULL;
}
return char_samp;
}
// Load a Char Samp from a dump file
CharSamp *CharSamp::FromCharDumpFile(FILE *fp) {
unsigned short left;
unsigned short top;
unsigned short page;
unsigned short first_char;
unsigned short last_char;
unsigned short norm_top;
unsigned short norm_bottom;
unsigned short norm_aspect_ratio;
unsigned int val32;
char_32 *label32;
// read and check 32 bit marker
if (fread(&val32, 1, sizeof(val32), fp) != sizeof(val32)) {
return NULL;
}
if (val32 != 0xabd0fefe) {
return NULL;
}
// read label length,
if (fread(&val32, 1, sizeof(val32), fp) != sizeof(val32)) {
return NULL;
}
// the label is not null terminated in the file
if (val32 > 0 && val32 < MAX_UINT32) {
label32 = new char_32[val32 + 1];
if (label32 == NULL) {
return NULL;
}
// read label
if (fread(label32, 1, val32 * sizeof(*label32), fp) !=
(val32 * sizeof(*label32))) {
delete [] label32;
return NULL;
}
// null terminate
label32[val32] = 0;
} else {
label32 = NULL;
}
// read coordinates
if (fread(&page, 1, sizeof(page), fp) != sizeof(page) ||
fread(&left, 1, sizeof(left), fp) != sizeof(left) ||
fread(&top, 1, sizeof(top), fp) != sizeof(top) ||
fread(&first_char, 1, sizeof(first_char), fp) != sizeof(first_char) ||
fread(&last_char, 1, sizeof(last_char), fp) != sizeof(last_char) ||
fread(&norm_top, 1, sizeof(norm_top), fp) != sizeof(norm_top) ||
fread(&norm_bottom, 1, sizeof(norm_bottom), fp) != sizeof(norm_bottom) ||
fread(&norm_aspect_ratio, 1, sizeof(norm_aspect_ratio), fp) !=
sizeof(norm_aspect_ratio)) {
delete [] label32;
return NULL;
}
// create the object
CharSamp *char_samp = new CharSamp();
if (char_samp == NULL) {
delete [] label32;
return NULL;
}
// init
char_samp->label32_ = label32;
char_samp->page_ = page;
char_samp->left_ = left;
char_samp->top_ = top;
char_samp->first_char_ = first_char;
char_samp->last_char_ = last_char;
char_samp->norm_top_ = norm_top;
char_samp->norm_bottom_ = norm_bottom;
char_samp->norm_aspect_ratio_ = norm_aspect_ratio;
// load the Bmp8 part
if (char_samp->LoadFromCharDumpFile(fp) == false) {
delete char_samp; // It owns label32.
return NULL;
}
return char_samp;
}
// returns a copy of the charsamp that is scaled to the
// specified width and height
CharSamp *CharSamp::Scale(int wid, int hgt, bool isotropic) {
CharSamp *scaled_samp = new CharSamp(wid, hgt);
if (scaled_samp == NULL) {
return NULL;
}
if (scaled_samp->ScaleFrom(this, isotropic) == false) {
delete scaled_samp;
return NULL;
}
scaled_samp->left_ = left_;
scaled_samp->top_ = top_;
scaled_samp->page_ = page_;
scaled_samp->SetLabel(label32_);
scaled_samp->first_char_ = first_char_;
scaled_samp->last_char_ = last_char_;
scaled_samp->norm_top_ = norm_top_;
scaled_samp->norm_bottom_ = norm_bottom_;
scaled_samp->norm_aspect_ratio_ = norm_aspect_ratio_;
return scaled_samp;
}
// Load a Char Samp from a dump file
CharSamp *CharSamp::FromRawData(int left, int top, int wid, int hgt,
unsigned char *data) {
// create the object
CharSamp *char_samp = new CharSamp(left, top, wid, hgt);
if (char_samp == NULL) {
return NULL;
}
if (char_samp->LoadFromRawData(data) == false) {
delete char_samp;
return NULL;
}
return char_samp;
}
// Saves the charsamp to a dump file
bool CharSamp::Save2CharDumpFile(FILE *fp) const {
unsigned int val32;
// write and check 32 bit marker
val32 = 0xabd0fefe;
if (fwrite(&val32, 1, sizeof(val32), fp) != sizeof(val32)) {
return false;
}
// write label length
val32 = (label32_ == NULL) ? 0 : LabelLen(label32_);
if (fwrite(&val32, 1, sizeof(val32), fp) != sizeof(val32)) {
return false;
}
// write label
if (label32_ != NULL) {
if (fwrite(label32_, 1, val32 * sizeof(*label32_), fp) !=
(val32 * sizeof(*label32_))) {
return false;
}
}
// write coordinates
if (fwrite(&page_, 1, sizeof(page_), fp) != sizeof(page_)) {
return false;
}
if (fwrite(&left_, 1, sizeof(left_), fp) != sizeof(left_)) {
return false;
}
if (fwrite(&top_, 1, sizeof(top_), fp) != sizeof(top_)) {
return false;
}
if (fwrite(&first_char_, 1, sizeof(first_char_), fp) !=
sizeof(first_char_)) {
return false;
}
if (fwrite(&last_char_, 1, sizeof(last_char_), fp) != sizeof(last_char_)) {
return false;
}
if (fwrite(&norm_top_, 1, sizeof(norm_top_), fp) != sizeof(norm_top_)) {
return false;
}
if (fwrite(&norm_bottom_, 1, sizeof(norm_bottom_), fp) !=
sizeof(norm_bottom_)) {
return false;
}
if (fwrite(&norm_aspect_ratio_, 1, sizeof(norm_aspect_ratio_), fp) !=
sizeof(norm_aspect_ratio_)) {
return false;
}
if (SaveBmp2CharDumpFile(fp) == false) {
return false;
}
return true;
}
// Crop the char samp such that there are no white spaces on any side.
// The norm_top_ and norm_bottom_ fields are the character top/bottom
// with respect to whatever context the character is being recognized
// in (e.g. word bounding box) normalized to a standard size of
// 255. Here they default to 0 and 255 (word box boundaries), but
// since they are context dependent, they may need to be reset by the
// calling function.
CharSamp *CharSamp::Crop() {
// get the dimesions of the cropped img
int cropped_left = 0;
int cropped_top = 0;
int cropped_wid = wid_;
int cropped_hgt = hgt_;
Bmp8::Crop(&cropped_left, &cropped_top,
&cropped_wid, &cropped_hgt);
if (cropped_wid == 0 || cropped_hgt == 0) {
return NULL;
}
// create the cropped char samp
CharSamp *cropped_samp = new CharSamp(left_ + cropped_left,
top_ + cropped_top,
cropped_wid, cropped_hgt);
cropped_samp->SetLabel(label32_);
cropped_samp->SetFirstChar(first_char_);
cropped_samp->SetLastChar(last_char_);
// the following 3 fields may/should be reset by the calling function
// using context information, i.e., location of character box
// w.r.t. the word bounding box
cropped_samp->SetNormAspectRatio(255 *
cropped_wid / (cropped_wid + cropped_hgt));
cropped_samp->SetNormTop(0);
cropped_samp->SetNormBottom(255);
// copy the bitmap to the cropped img
Copy(cropped_left, cropped_top, cropped_wid, cropped_hgt, cropped_samp);
return cropped_samp;
}
// segment the char samp to connected components
// based on contiguity and vertical pixel density histogram
ConComp **CharSamp::Segment(int *segment_cnt, bool right_2_left,
int max_hist_wnd, int min_con_comp_size) const {
// init
(*segment_cnt) = 0;
int concomp_cnt = 0;
int seg_cnt = 0;
// find the concomps of the image
ConComp **concomp_array = FindConComps(&concomp_cnt, min_con_comp_size);
if (concomp_cnt <= 0 || !concomp_array) {
if (concomp_array)
delete []concomp_array;
return NULL;
}
ConComp **seg_array = NULL;
// segment each concomp further using vertical histogram
for (int concomp = 0; concomp < concomp_cnt; concomp++) {
int concomp_seg_cnt = 0;
// segment the concomp
ConComp **concomp_seg_array = NULL;
ConComp **concomp_alloc_seg =
concomp_array[concomp]->Segment(max_hist_wnd, &concomp_seg_cnt);
// no segments, add the whole concomp
if (concomp_alloc_seg == NULL) {
concomp_seg_cnt = 1;
concomp_seg_array = concomp_array + concomp;
} else {
// delete the original concomp, we no longer need it
concomp_seg_array = concomp_alloc_seg;
delete concomp_array[concomp];
}
// add the resulting segments
for (int seg_idx = 0; seg_idx < concomp_seg_cnt; seg_idx++) {
// too small of a segment: ignore
if (concomp_seg_array[seg_idx]->Width() < 2 &&
concomp_seg_array[seg_idx]->Height() < 2) {
delete concomp_seg_array[seg_idx];
} else {
// add the new segment
// extend the segment array
if ((seg_cnt % kConCompAllocChunk) == 0) {
ConComp **temp_segm_array =
new ConComp *[seg_cnt + kConCompAllocChunk];
if (temp_segm_array == NULL) {
fprintf(stderr, "Cube ERROR (CharSamp::Segment): could not "
"allocate additional connected components\n");
delete []concomp_seg_array;
delete []concomp_array;
delete []seg_array;
return NULL;
}
if (seg_cnt > 0) {
memcpy(temp_segm_array, seg_array, seg_cnt * sizeof(*seg_array));
delete []seg_array;
}
seg_array = temp_segm_array;
}
seg_array[seg_cnt++] = concomp_seg_array[seg_idx];
}
} // segment
if (concomp_alloc_seg != NULL) {
delete []concomp_alloc_seg;
}
} // concomp
delete []concomp_array;
// sort the concomps from Left2Right or Right2Left, based on the reading order
if (seg_cnt > 0 && seg_array != NULL) {
qsort(seg_array, seg_cnt, sizeof(*seg_array), right_2_left ?
ConComp::Right2LeftComparer : ConComp::Left2RightComparer);
}
(*segment_cnt) = seg_cnt;
return seg_array;
}
// builds a char samp from a set of connected components
CharSamp *CharSamp::FromConComps(ConComp **concomp_array, int strt_concomp,
int seg_flags_size, int *seg_flags,
bool *left_most, bool *right_most,
int word_hgt) {
int concomp;
int end_concomp;
int concomp_cnt = 0;
end_concomp = strt_concomp + seg_flags_size;
// determine ID range
bool once = false;
int min_id = -1;
int max_id = -1;
for (concomp = strt_concomp; concomp < end_concomp; concomp++) {
if (!seg_flags || seg_flags[concomp - strt_concomp] != 0) {
if (!once) {
min_id = concomp_array[concomp]->ID();
max_id = concomp_array[concomp]->ID();
once = true;
} else {
UpdateRange(concomp_array[concomp]->ID(), &min_id, &max_id);
}
concomp_cnt++;
}
}
if (concomp_cnt < 1 || !once || min_id == -1 || max_id == -1) {
return NULL;
}
// alloc memo for computing leftmost and right most attributes
int id_cnt = max_id - min_id + 1;
bool *id_exist = new bool[id_cnt];
bool *left_most_exist = new bool[id_cnt];
bool *right_most_exist = new bool[id_cnt];
if (!id_exist || !left_most_exist || !right_most_exist)
return NULL;
memset(id_exist, 0, id_cnt * sizeof(*id_exist));
memset(left_most_exist, 0, id_cnt * sizeof(*left_most_exist));
memset(right_most_exist, 0, id_cnt * sizeof(*right_most_exist));
// find the dimensions of the charsamp
once = false;
int left = -1;
int right = -1;
int top = -1;
int bottom = -1;
int unq_ids = 0;
int unq_left_most = 0;
int unq_right_most = 0;
for (concomp = strt_concomp; concomp < end_concomp; concomp++) {
if (!seg_flags || seg_flags[concomp - strt_concomp] != 0) {
if (!once) {
left = concomp_array[concomp]->Left();
right = concomp_array[concomp]->Right();
top = concomp_array[concomp]->Top();
bottom = concomp_array[concomp]->Bottom();
once = true;
} else {
UpdateRange(concomp_array[concomp]->Left(),
concomp_array[concomp]->Right(), &left, &right);
UpdateRange(concomp_array[concomp]->Top(),
concomp_array[concomp]->Bottom(), &top, &bottom);
}
// count unq ids, unq left most and right mosts ids
int concomp_id = concomp_array[concomp]->ID() - min_id;
if (!id_exist[concomp_id]) {
id_exist[concomp_id] = true;
unq_ids++;
}
if (concomp_array[concomp]->LeftMost()) {
if (left_most_exist[concomp_id] == false) {
left_most_exist[concomp_id] = true;
unq_left_most++;
}
}
if (concomp_array[concomp]->RightMost()) {
if (right_most_exist[concomp_id] == false) {
right_most_exist[concomp_id] = true;
unq_right_most++;
}
}
}
}
delete []id_exist;
delete []left_most_exist;
delete []right_most_exist;
if (!once || left == -1 || top == -1 || right == -1 || bottom == -1) {
return NULL;
}
(*left_most) = (unq_left_most >= unq_ids);
(*right_most) = (unq_right_most >= unq_ids);
// create the char sample object
CharSamp *samp = new CharSamp(left, top, right - left + 1, bottom - top + 1);
if (!samp) {
return NULL;
}
// set the foreground pixels
for (concomp = strt_concomp; concomp < end_concomp; concomp++) {
if (!seg_flags || seg_flags[concomp - strt_concomp] != 0) {
ConCompPt *pt_ptr = concomp_array[concomp]->Head();
while (pt_ptr) {
samp->line_buff_[pt_ptr->y() - top][pt_ptr->x() - left] = 0;
pt_ptr = pt_ptr->Next();
}
}
}
return samp;
}
// clones the object
CharSamp *CharSamp::Clone() const {
// create the cropped char samp
CharSamp *samp = new CharSamp(left_, top_, wid_, hgt_);
samp->SetLabel(label32_);
samp->SetFirstChar(first_char_);
samp->SetLastChar(last_char_);
samp->SetNormTop(norm_top_);
samp->SetNormBottom(norm_bottom_);
samp->SetNormAspectRatio(norm_aspect_ratio_);
// copy the bitmap to the cropped img
Copy(0, 0, wid_, hgt_, samp);
return samp;
}
// Load a Char Samp from a dump file
CharSamp *CharSamp::FromCharDumpFile(unsigned char **raw_data_ptr) {
unsigned int val32;
char_32 *label32;
unsigned char *raw_data = *raw_data_ptr;
// read and check 32 bit marker
memcpy(&val32, raw_data, sizeof(val32));
raw_data += sizeof(val32);
if (val32 != 0xabd0fefe) {
return NULL;
}
// read label length,
memcpy(&val32, raw_data, sizeof(val32));
raw_data += sizeof(val32);
// the label is not null terminated in the file
if (val32 > 0 && val32 < MAX_UINT32) {
label32 = new char_32[val32 + 1];
if (label32 == NULL) {
return NULL;
}
// read label
memcpy(label32, raw_data, val32 * sizeof(*label32));
raw_data += (val32 * sizeof(*label32));
// null terminate
label32[val32] = 0;
} else {
label32 = NULL;
}
// create the object
CharSamp *char_samp = new CharSamp();
if (char_samp == NULL) {
return NULL;
}
// read coordinates
char_samp->label32_ = label32;
memcpy(&char_samp->page_, raw_data, sizeof(char_samp->page_));
raw_data += sizeof(char_samp->page_);
memcpy(&char_samp->left_, raw_data, sizeof(char_samp->left_));
raw_data += sizeof(char_samp->left_);
memcpy(&char_samp->top_, raw_data, sizeof(char_samp->top_));
raw_data += sizeof(char_samp->top_);
memcpy(&char_samp->first_char_, raw_data, sizeof(char_samp->first_char_));
raw_data += sizeof(char_samp->first_char_);
memcpy(&char_samp->last_char_, raw_data, sizeof(char_samp->last_char_));
raw_data += sizeof(char_samp->last_char_);
memcpy(&char_samp->norm_top_, raw_data, sizeof(char_samp->norm_top_));
raw_data += sizeof(char_samp->norm_top_);
memcpy(&char_samp->norm_bottom_, raw_data, sizeof(char_samp->norm_bottom_));
raw_data += sizeof(char_samp->norm_bottom_);
memcpy(&char_samp->norm_aspect_ratio_, raw_data,
sizeof(char_samp->norm_aspect_ratio_));
raw_data += sizeof(char_samp->norm_aspect_ratio_);
// load the Bmp8 part
if (char_samp->LoadFromCharDumpFile(&raw_data) == false) {
delete char_samp;
return NULL;
}
(*raw_data_ptr) = raw_data;
return char_samp;
}
// computes the features corresponding to the char sample
bool CharSamp::ComputeFeatures(int conv_grid_size, float *features) {
// Create a scaled BMP
CharSamp *scaled_bmp = Scale(conv_grid_size, conv_grid_size);
if (!scaled_bmp) {
return false;
}
// prepare input
unsigned char *buff = scaled_bmp->RawData();
// bitmap features
int input;
int bmp_size = conv_grid_size * conv_grid_size;
for (input = 0; input < bmp_size; input++) {
features[input] = 255.0f - (1.0f * buff[input]);
}
// word context features
features[input++] = FirstChar();
features[input++] = LastChar();
features[input++] = NormTop();
features[input++] = NormBottom();
features[input++] = NormAspectRatio();
delete scaled_bmp;
return true;
}
} // namespace tesseract