Hello,
I wanted to include pdf slides from:
http://ais.informatik.uni-freiburg.de/lehre/ss03/ki/slides/01-intro.pdf
by pdfTeX, but the colors in some of the images are terrible wrong.
Driver file:
% test.tex
\nopagenumbers
\pdfcompresslevel=0
\pdfximage width 297bp height 210bp page 14 {01-intro.pdf}
% similar page 9, ...
\pdfrefximage\pdflastximage
\bye
Analysis:
01-intro.pdf / test.pdf
/Page object: 107 0 / 3 0
It references via /XObject the /Image object:
/Image object: 110 0 / 8 0
With
/ColorSpace object: 111 0 / 7 0
Start of object 111 0 of 01-intro.pdf:
111 0 obj
[/Indexed
/DeviceRGB
255
<0402070402300402500402700402840402EC3502066E021585020A9A02159C02
...
Start of object 7 0 of test.pdf with one line break for readability:
7 0 obj
[/Indexed/DeviceRGB 255
(\004\002\007\004\0020\004\002P\004\002p\004\002\37777777604
\004\002\377777777545\002\006n\002\025\37777777605\002...
==> The translation of 8-bit characters that have set it eighth bit
get terrible wrong:
hex(84) --> string(\37777777604)
hex(EC) --> string(\37777777754)
It seems that the octal number is written as 32 bit number instead
of a 8 bit number.
Yours sincerely
Heiko
On Tue, 29 Jul 2003, Heiko Oberdiek wrote:
by pdfTeX, but the colors in some of the images are terrible wrong.
A typecast is missing in pdftexdir/pdftoepdf.cc, function copyObject(): pdf_puts("("); for (; *p != 0; p++) { c = (unsigned char) *p; // <--- typecast here! if (c == '(' || c == ')' || c == '\\') pdf_printf("\\%c", c); else if (c < 0x20 || c > 0x7F) pdf_printf("\\%03o", c); Greetings Hartmut
On Tue, Jul 29, 2003 at 09:15:22PM +0200, Hartmut Henkel wrote:
On Tue, 29 Jul 2003, Heiko Oberdiek wrote:
by pdfTeX, but the colors in some of the images are terrible wrong.
A typecast is missing in pdftexdir/pdftoepdf.cc, function copyObject():
pdf_puts("("); for (; *p != 0; p++) { c = (unsigned char) *p; // <--- typecast here! if (c == '(' || c == ')' || c == '\\') pdf_printf("\\%c", c); else if (c < 0x20 || c > 0x7F) pdf_printf("\\%03o", c);
Very nice, we found the same cause and fix. :-)
Best regards
Heiko
On 2003-07-29 21:15:22 +0200, Hartmut Henkel wrote:
On Tue, 29 Jul 2003, Heiko Oberdiek wrote:
by pdfTeX, but the colors in some of the images are terrible wrong.
A typecast is missing in pdftexdir/pdftoepdf.cc, function copyObject():
Still? I thought gcc -Wall -pedantic had cought these... :-( Will fix it. Best regards Martin -- Martin Schröder, MS@ArtCom-GmbH.DE ArtCom GmbH, Lise-Meitner-Str 5, 28359 Bremen, Germany Voice +49 421 20419-44 / Fax +49 421 20419-10
Hello,
and the fix for the image color problem that is a write problem
of strings in PDF syntax:
Patch 8BitString
I wanted to include pdf slides from:
http://ais.informatik.uni-freiburg.de/lehre/ss03/ki/slides/01-intro.pdf
by pdfTeX, but the colors in some of the images are terrible wrong.
Driver file:
% test.tex
\nopagenumbers
\pdfcompresslevel=0
\pdfximage width 297bp height 210bp page 14 {01-intro.pdf}
% similar page 9, ...
\pdfrefximage\pdflastximage
\bye
Analysis:
01-intro.pdf / test.pdf
/Page object: 107 0 / 3 0
It references via /XObject the /Image object:
/Image object: 110 0 / 8 0
With
/ColorSpace object: 111 0 / 7 0
Start of object 111 0 of 01-intro.pdf:
111 0 obj
[/Indexed
/DeviceRGB
255
<0402070402300402500402700402840402EC3502066E021585020A9A02159C02
...
Start of object 7 0 of test.pdf with one line break for readability:
7 0 obj
[/Indexed/DeviceRGB 255
(\004\002\007\004\0020\004\002P\004\002p\004\002\37777777604
\004\002\377777777545\002\006n\002\025\37777777605\002...
==> The translation of 8-bit characters that have set it eighth bit
get terrible wrong:
hex(84) --> string(\37777777604)
hex(EC) --> string(\37777777754)
It seems that the octal number is written as 32 bit number instead
of a 8 bit number.
Another test file scenario:
% include.tex:
\pdfinfo{/Title<0204840204>}
\nopagenumbers
\hbox{}
\bye
% test.tex:
\pdfcompresslevel=0
\pdfximage width 210bp height 297bp {test.pdf}
\pdfrefximage\pdflastximage
\nopagenumbers
\bye
==> /Title (\002\004\37777777604\002\004)
After the following patch:
==> /Title (\002\004\204\002\004)
Problem detected in pdftoepdf.cc:
static void copyObject(Object *obj)
{
...
int i, l, c;
...
else if (obj->isString()) {
s = obj->getString();
p = s->getCString();
l = s->getLength();
if (strlen(p) == (unsigned int)l) {
pdf_puts("(");
for (; *p != 0; p++) {
% original: c = *p;
% fix: c = (unsigned char)*p;
if (c == '(' || c == ')' || c == '\\')
pdf_printf("\\%c", c);
else if (c < 0x20 || c > 0x7F)
pdf_printf("\\%03o", c);
else
pdfout(c);
}
pdf_puts(")");
}
The sign extension of *p with type "signed char" (8 bit)
to c with type "signed int" (32 bit) can explain the effect.
Alternatively
pdf_printf("\\%03o", c);
can be changed to
pdf_printf("\\%03o", (unsigned char)c);
Patch files based on 2003/07/29 v1.11a:
pdftoepdf.cc.diff for TeX/texk/web2c/pdftexdir/pdftoepdf.cc
Yours sincerely
Heiko
On 2003-07-29 22:20:34 +0200, Heiko Oberdiek wrote:
*** pdftoepdf.cc.org Tue Jul 29 21:41:13 2003 --- pdftoepdf.cc Tue Jul 29 22:06:34 2003 *************** *** 559,565 **** if (strlen(p) == (unsigned int)l) { pdf_puts("("); for (; *p != 0; p++) { ! c = *p; if (c == '(' || c == ')' || c == '\\') pdf_printf("\\%c", c); else if (c < 0x20 || c > 0x7F) --- 559,565 ---- if (strlen(p) == (unsigned int)l) { pdf_puts("("); for (; *p != 0; p++) { ! c = (unsigned char)*p; if (c == '(' || c == ')' || c == '\\') pdf_printf("\\%c", c); else if (c < 0x20 || c > 0x7F)
It's in (#3496). Is there any way to catch bugs like these with gcc? Or is C just broken? Best regards Martin -- Martin Schröder, MS@ArtCom-GmbH.DE ArtCom GmbH, Lise-Meitner-Str 5, 28359 Bremen, Germany Voice +49 421 20419-44 / Fax +49 421 20419-10
participants (3)
-
Hartmut Henkel -
Heiko Oberdiek -
Martin Schroeder