Tenzin
I have been a bit successful training Tibetan using the Jomolhari font
on OS X. I found I needed to space the characters out a bit more when
they clumped together on he line. Then there is a bit more fiddling in
tesseractTrainer.py to merge boxes.
The merge function failed for me because the pygtk library didn't
handle unicode well. So, I wrote my own merge.
You will also have problems with sscanf reading the UTF-8 encoding for
some consonants. The Tibetan 30 character alphabet includes E0 BD 85
and E0 BD A0 characters. The file boxread.cpp uses sscanf with %s to
read UTF-8 Unicode strings. Unfortunately, U+0085 NEL (control
character next line) and U+00A0 NBSP (NO-BREAK SPACE) are treated as
whitespace by sscanf, so only the first two bytes are read. So all
scanf's doing %s reads of unicode UTF-8 chars need to be replaced by
code which does a simple scan to avoid truncating the encoding.
I'm using 2.04, but trying to get 3.0 going but the new unified file
format needs to be cracked.
Here is my fix or the sscanf problem:
bool read_next_box(int target_page, FILE* box_file, char* utf8_str,
int* x_min, int* y_min, int* x_max, int* y_max) {
static int line = 0;
int count = 0;
int page = 0;
char buff[kBoxReadBufSize]; //boxfile read buffer
char *uch;
char *buffptr = buff;
while (fgets(buff, sizeof(buff) - 1, box_file)) {
line++;
buffptr = buff;
const unsigned char *ubuf = reinterpret_cast<const unsigned char*>
(buffptr);
if (ubuf[0] == 0xef && ubuf[1] == 0xbb && ubuf[2] == 0xbf)
buffptr += 3; // Skip unicode file designation.
/* Check for blank lines in box file */
while (*buffptr == ' ' || *buffptr == '\t')
buffptr++;
// change to simply scan over the uch rather than fail on bad
unicode sscan(%s") which fails on Tibetan consonants
uch = buffptr;
while (*buffptr != ' ' && *buffptr != '\t')
buffptr++;
if (*buffptr != '\0') {
*buffptr++ = 0;
count = sscanf(buffptr, "%d %d %d %d %d",
x_min, y_min, x_max, y_max, &page);
if (count != 5) {
page = 0;
count = sscanf(buffptr, "%d %d %d %d",
x_min, y_min, x_max, y_max);
}
if (target_page >= 0 && target_page != page)
continue; // Not on the appropriate page.
if (count == 4) {
#if debug_utf8
// Print the hex codes of the utf8 code.
int x;
for (x = 0; buff[x] != '\0'; ++x)
tprintf("[%02x]", (unsigned char)buff[x]);
tprintf("\n");
for (x = 0; uch[x] != '\0'; ++x)
tprintf("[%02x]", (unsigned char)uch[x]);
tprintf(" %d %d %d %d\n", *x_min, *y_min, *x_max, *y_max);
#endif
// Validate UTF8 by making unichars with it.
int used = 0;
int uch_len = strlen(uch);
while (used < uch_len) {
UNICHAR ch(uch + used, uch_len - used);
int new_used = ch.utf8_len();
if (new_used == 0) {
tprintf("Bad utf-8 char starting with 0x%02x at col %d,
line %d \n",
(unsigned char)uch[used], used + 1, line);
count = 0;
break;
}
used += new_used;
}
if (uch_len > UNICHAR_LEN) {
tprintf("utf-8 string too long at line %d\n", line);
count = 0;
}
}
if (count < 4) {
tprintf("Box file format error on line %i ignored\n", line);
} else {
strcpy(utf8_str, uch);
return true; //read a box ok
}
}
}
fclose(box_file);
line = 0;
return false; //EOF
}
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