tesseract/cube/cube_utils.cpp
2015-07-24 11:51:44 +02:00

414 lines
11 KiB
C++

/**********************************************************************
* File: cube_utils.cpp
* Description: Implementation of the Cube Utilities Class
* Author: Ahmad Abdulkader
* Created: 2008
*
* (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 <math.h>
#include <string>
#include <vector>
#include "cube_utils.h"
#include "char_set.h"
#include "unichar.h"
namespace tesseract {
CubeUtils::CubeUtils() {
}
CubeUtils::~CubeUtils() {
}
/**
* convert a prob to a cost (-ve log prob)
*/
int CubeUtils::Prob2Cost(double prob_val) {
if (prob_val < MIN_PROB) {
return MIN_PROB_COST;
}
return static_cast<int>(-log(prob_val) * PROB2COST_SCALE);
}
/**
* converts a cost to probability
*/
double CubeUtils::Cost2Prob(int cost) {
return exp(-cost / PROB2COST_SCALE);
}
/**
* computes the length of a NULL terminated char_32 string
*/
int CubeUtils::StrLen(const char_32 *char_32_ptr) {
if (char_32_ptr == NULL) {
return 0;
}
int len = -1;
while (char_32_ptr[++len]);
return len;
}
/**
* compares two char_32 strings
*/
int CubeUtils::StrCmp(const char_32 *str1, const char_32 *str2) {
const char_32 *pch1 = str1;
const char_32 *pch2 = str2;
for (; (*pch1) != 0 && (*pch2) != 0; pch1++, pch2++) {
if ((*pch1) != (*pch2)) {
return (*pch1) - (*pch2);
}
}
if ((*pch1) == 0) {
if ((*pch2) == 0) {
return 0;
} else {
return -1;
}
} else {
return 1;
}
}
/**
* Duplicates a 32-bit char buffer
*/
char_32 *CubeUtils::StrDup(const char_32 *str32) {
int len = StrLen(str32);
char_32 *new_str = new char_32[len + 1];
if (new_str == NULL) {
return NULL;
}
memcpy(new_str, str32, len * sizeof(*str32));
new_str[len] = 0;
return new_str;
}
/**
* creates a char samp from a specified portion of the image
*/
CharSamp *CubeUtils::CharSampleFromPix(Pix *pix, int left, int top,
int wid, int hgt) {
// get the raw img data from the image
unsigned char *temp_buff = GetImageData(pix, left, top, wid, hgt);
if (temp_buff == NULL) {
return NULL;
}
// create a char samp from temp buffer
CharSamp *char_samp = CharSamp::FromRawData(left, top, wid, hgt, temp_buff);
// clean up temp buffer
delete []temp_buff;
return char_samp;
}
/**
* create a B/W image from a char_sample
*/
Pix *CubeUtils::PixFromCharSample(CharSamp *char_samp) {
// parameter check
if (char_samp == NULL) {
return NULL;
}
// get the raw data
int stride = char_samp->Stride();
int wid = char_samp->Width();
int hgt = char_samp->Height();
Pix *pix = pixCreate(wid, hgt, 1);
if (pix == NULL) {
return NULL;
}
// copy the contents
unsigned char *line = char_samp->RawData();
for (int y = 0; y < hgt ; y++, line += stride) {
for (int x = 0; x < wid; x++) {
if (line[x] != 0) {
pixSetPixel(pix, x, y, 0);
} else {
pixSetPixel(pix, x, y, 255);
}
}
}
return pix;
}
/**
* creates a raw buffer from the specified location of the pix
*/
unsigned char *CubeUtils::GetImageData(Pix *pix, int left, int top,
int wid, int hgt) {
// skip invalid dimensions
if (left < 0 || top < 0 || wid < 0 || hgt < 0 ||
(left + wid) > pix->w || (top + hgt) > pix->h ||
pix->d != 1) {
return NULL;
}
// copy the char img to a temp buffer
unsigned char *temp_buff = new unsigned char[wid * hgt];
if (temp_buff == NULL) {
return NULL;
}
l_int32 w;
l_int32 h;
l_int32 d;
l_int32 wpl;
l_uint32 *line;
l_uint32 *data;
pixGetDimensions(pix, &w, &h, &d);
wpl = pixGetWpl(pix);
data = pixGetData(pix);
line = data + (top * wpl);
for (int y = 0, off = 0; y < hgt ; y++) {
for (int x = 0; x < wid; x++, off++) {
temp_buff[off] = GET_DATA_BIT(line, x + left) ? 0 : 255;
}
line += wpl;
}
return temp_buff;
}
/**
* read file contents to a string
*/
bool CubeUtils::ReadFileToString(const string &file_name, string *str) {
str->clear();
FILE *fp = fopen(file_name.c_str(), "rb");
if (fp == NULL) {
return false;
}
// get the size of the size
fseek(fp, 0, SEEK_END);
int file_size = ftell(fp);
if (file_size < 1) {
fclose(fp);
return false;
}
// adjust string size
str->reserve(file_size);
// read the contents
rewind(fp);
char *buff = new char[file_size];
if (buff == NULL) {
fclose(fp);
return false;
}
int read_bytes = fread(buff, 1, static_cast<int>(file_size), fp);
if (read_bytes == file_size) {
str->append(buff, file_size);
}
delete []buff;
fclose(fp);
return (read_bytes == file_size);
}
/**
* splits a string into vectors based on specified delimiters
*/
void CubeUtils::SplitStringUsing(const string &str,
const string &delims,
vector<string> *str_vec) {
// Optimize the common case where delims is a single character.
if (delims[0] != '\0' && delims[1] == '\0') {
char c = delims[0];
const char* p = str.data();
const char* end = p + str.size();
while (p != end) {
if (*p == c) {
++p;
} else {
const char* start = p;
while (++p != end && *p != c);
str_vec->push_back(string(start, p - start));
}
}
return;
}
string::size_type begin_index, end_index;
begin_index = str.find_first_not_of(delims);
while (begin_index != string::npos) {
end_index = str.find_first_of(delims, begin_index);
if (end_index == string::npos) {
str_vec->push_back(str.substr(begin_index));
return;
}
str_vec->push_back(str.substr(begin_index, (end_index - begin_index)));
begin_index = str.find_first_not_of(delims, end_index);
}
}
/**
* UTF-8 to UTF-32 conversion functions
*/
void CubeUtils::UTF8ToUTF32(const char *utf8_str, string_32 *str32) {
str32->clear();
int len = strlen(utf8_str);
int step = 0;
for (int ch = 0; ch < len; ch += step) {
step = UNICHAR::utf8_step(utf8_str + ch);
if (step > 0) {
UNICHAR uni_ch(utf8_str + ch, step);
(*str32) += uni_ch.first_uni();
}
}
}
/**
* UTF-32 to UTF-8 conversion functions
*/
void CubeUtils::UTF32ToUTF8(const char_32 *utf32_str, string *str) {
str->clear();
for (const char_32 *ch_32 = utf32_str; (*ch_32) != 0; ch_32++) {
UNICHAR uni_ch((*ch_32));
char *utf8 = uni_ch.utf8_str();
if (utf8 != NULL) {
(*str) += utf8;
delete []utf8;
}
}
}
bool CubeUtils::IsCaseInvariant(const char_32 *str32, CharSet *char_set) {
bool all_one_case = true;
bool capitalized;
bool prev_upper;
bool prev_lower;
bool first_upper;
bool first_lower;
bool cur_upper;
bool cur_lower;
string str8;
if (!char_set) {
// If cube char_set is missing, use C-locale-dependent functions
// on UTF8 characters to determine case properties.
first_upper = isupper(str32[0]);
first_lower = islower(str32[0]);
if (first_upper)
capitalized = true;
prev_upper = first_upper;
prev_lower = islower(str32[0]);
for (int c = 1; str32[c] != 0; ++c) {
cur_upper = isupper(str32[c]);
cur_lower = islower(str32[c]);
if ((prev_upper && cur_lower) || (prev_lower && cur_upper))
all_one_case = false;
if (cur_upper)
capitalized = false;
prev_upper = cur_upper;
prev_lower = cur_lower;
}
} else {
UNICHARSET *unicharset = char_set->InternalUnicharset();
// Use UNICHARSET functions to determine case properties
first_upper = unicharset->get_isupper(char_set->ClassID(str32[0]));
first_lower = unicharset->get_islower(char_set->ClassID(str32[0]));
if (first_upper)
capitalized = true;
prev_upper = first_upper;
prev_lower = unicharset->get_islower(char_set->ClassID(str32[0]));
for (int c = 1; c < StrLen(str32); ++c) {
cur_upper = unicharset->get_isupper(char_set->ClassID(str32[c]));
cur_lower = unicharset->get_islower(char_set->ClassID(str32[c]));
if ((prev_upper && cur_lower) || (prev_lower && cur_upper))
all_one_case = false;
if (cur_upper)
capitalized = false;
prev_upper = cur_upper;
prev_lower = cur_lower;
}
}
return all_one_case || capitalized;
}
char_32 *CubeUtils::ToLower(const char_32 *str32, CharSet *char_set) {
if (!char_set) {
return NULL;
}
UNICHARSET *unicharset = char_set->InternalUnicharset();
int len = StrLen(str32);
char_32 *lower = new char_32[len + 1];
if (!lower)
return NULL;
for (int i = 0; i < len; ++i) {
char_32 ch = str32[i];
if (ch == INVALID_UNICHAR_ID) {
delete [] lower;
return NULL;
}
// convert upper-case characters to lower-case
if (unicharset->get_isupper(char_set->ClassID(ch))) {
UNICHAR_ID uid_lower = unicharset->get_other_case(char_set->ClassID(ch));
const char_32 *str32_lower = char_set->ClassString(uid_lower);
// expect lower-case version of character to be a single character
if (!str32_lower || StrLen(str32_lower) != 1) {
delete [] lower;
return NULL;
}
lower[i] = str32_lower[0];
} else {
lower[i] = ch;
}
}
lower[len] = 0;
return lower;
}
char_32 *CubeUtils::ToUpper(const char_32 *str32, CharSet *char_set) {
if (!char_set) {
return NULL;
}
UNICHARSET *unicharset = char_set->InternalUnicharset();
int len = StrLen(str32);
char_32 *upper = new char_32[len + 1];
if (!upper)
return NULL;
for (int i = 0; i < len; ++i) {
char_32 ch = str32[i];
if (ch == INVALID_UNICHAR_ID) {
delete [] upper;
return NULL;
}
// convert lower-case characters to upper-case
if (unicharset->get_islower(char_set->ClassID(ch))) {
UNICHAR_ID uid_upper = unicharset->get_other_case(char_set->ClassID(ch));
const char_32 *str32_upper = char_set->ClassString(uid_upper);
// expect upper-case version of character to be a single character
if (!str32_upper || StrLen(str32_upper) != 1) {
delete [] upper;
return NULL;
}
upper[i] = str32_upper[0];
} else {
upper[i] = ch;
}
}
upper[len] = 0;
return upper;
}
} // namespace tesseract