ID: 25581
Updated by: [EMAIL PROTECTED]
Reported By: willertan1980 at yahoo dot com
-Status: Open
+Status: Assigned
Bug Type: Feature/Change Request
Operating System: *
PHP Version: 4.3.3
Assigned To: helly
Previous Comments:
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[2003-09-22 00:35:43] willertan1980 at yahoo dot com
I wish to make it clear. I did not find this bug from somewhere else.
Ok, maybe I was to blame by not making a good explanation
I just installed the latest version (php 4.3.3) as told
And the problem still exists
The problem file – Bitmap file saved by using OS2/1.x or Win 2.x
header
(You can generate this file by using Photoshop, just draw something and
save it with
Save As: bmp-> file format -> choose OS/2 instead of windows)
This time, I do a check on PHP source code (php 4.3.3)
And I found this bug at
\ext\standard\image.c (lines 154)
result->width =
(((unsigned int)dim[ 3]) << 24) + (((unsigned int)dim[ 2]) << 16) +
(((unsigned int)dim[ 1]) << 8) + ((unsigned int) dim[ 0]);
result->height =
(((unsigned int)dim[ 7]) << 24) + (((unsigned int)dim[ 6]) << 16) +
(((unsigned int)dim[ 5]) << 8) + ((unsigned int) dim[ 4]);
PHP was reading 4 bytes for each width and height, that is true if for
readings >win3.x and >os2 2.x, because it is LONG integer, but for os2
1.x and win 2.x it is SHORT int, should be read as 2 bytes SHORT
OLDER VERSION - os2 1.x and win 2.x
DWORD biSize; //
SHORT biWidth;
SHORT biHeight;
WORD biPlanes;
WORD biBitCount;
NEWER VERSION >win3.x and >os2 2.x
DWORD biSize;
LONG biWidth;
LONG biHeight;
WORD biPlanes;
WORD biBitCount;
little-endian byte order
A HEX DUMP from Bitmap file that generated by Photoshop 7.0
width = 200 px = c8
height = 200 px = c8
(draw something and save it as bitmap (os2) 24bit)
// 2 bytes, magic bytes = ‘BM’
42 4d
// 4 bytes FileSize; 2 bytes Reserved1; 2 bytes Reserved2; 4 bytes
BitmapOffset
dc d4 01 00 00 00 00 00 1a 00 00 00
// 4 bytes, BiLength, bmp header length = 12
0c 00 00 00
Assumed win2.x
// 2 bytes Width; 2 bytes height; 2 bytes biplanes; 2 bytes biBitCount
c8 00 c8 00 01 00 18 00 ff ff ff ff ff
it is predicable by assuming getimagesize reads 4 bytes for width and
height, by the fact getimagesize did so.
Assumed win3.x
// 4 bytes width; 4 bytes height; 2 bytes biplanes; 2 bytes biBitCount
c8 00 c8 00 01 00 18 00 ff ff ff ff ff
Width = c8 00 c8 00
Height = 01 00 18 00
Bits = ff ff
by the fact getimagesize did this mistake in \ext\standard\image.c
(lines 154)
This is how getimagesize () flush out from
print_r(getimagesize('D:\Inetpub\New PHP artbook gen 7\Test
pic\_color\bitmap_os2.bmp' ));
Array ( [0] => 13107400 [1] => 1572865 [2] => 6 [3] => width="13107400"
height="1572865" [bits] => 65535 [mime] => image/bmp )
Width = 13107400 = 00 c8 00 c8 // 4 bytes
Height = 1572865 = 00 18 00 01 // 4 bytes
Bits = 65535 = ff ff
You can observed that by convert width values to hex (little-endian) =
c8 00 c8 00
Because os2 1.x (older version of bitmap) is 2 bytes in length but PHP
fetch it by 4 bytes.
It should be fix by -> If header length equal to 12, do below
result->width = (((unsigned int)dim[ 1]) << 8) + ((unsigned int) dim[
0]);
result->height = (((unsigned int)dim[ 3]) << 8) + ((unsigned int) dim[
2]);
result->bits = (((unsigned int)dim[7]) << 8) + ((unsigned int)dim[6]);
I think, more length check should be done, if PHP wishing to extend the
getimagesize() function on bmp.file
Here are some of my suggestions;
If length ==12 then read as bitmap win2.x or os/2 1.x
If length == 40 then read as bitmap win3.x
If length == 108 then read as bitmap win95 (version 4)
If length >12 and not 40 or 108 (typically 64, varying in size/fields)
then read as bitmap IBM OS/2 2.x <- this part making me really headache
:P
In addition, this is a “very old” windows bitmap structure, win1.x
typedef struct _Win1xHeader
{
WORD Type; /* File type identifier (always 0) */
WORD Width; /* Width of the bitmap in pixels */
WORD Height; /* Height of the bitmap in scan lines */
WORD ByteWidth; /* Width of bitmap in bytes */
BYTE Planes; /* Number of color planes */
BYTE BitsPerPixel; /* Number of bits per pixel */
} WIN1XHEADER;
my system
PHP 4.3.3 (bundled version)
OS: Windows sp1 on NTFS part ion
Server : IIS 5.1
Intel P4 cpu
------------------------------------------------------------------------
[2003-09-18 15:40:10] [EMAIL PROTECTED]
You realized wrong. We are only reading the 12 bytes that are the same
in all formats. Thus the error must by elsewhere. If you find out where
feel free to provide a patch. Until then we simply do not support such
images.
------------------------------------------------------------------------
[2003-09-17 16:38:14] willertan1980 at yahoo dot com
Description:
------------
getimagesize () return incorrect values on bitmap files
SYSTEM PHP 4.3.1(bundled version gd >1.6) , WinXP IIS 5.1 server, Intel
P4 CPU
TESTED image : RGB 24bits OS/2 bitmap (BM) generated by Photoshop 7.0
>>HEX DUMP image data 1st 32bytes - bitmaps header 12 bytes
4d 2c d0 01 00 00 00 00 00 1a 00 00
00 0c 00
00 f0 00 a5 00 01 00 18 00 b0 7f 6d
a9 75 62
i realized that getimagesize () read OS/2 1.x bitmap by using Windows
3.x / OS/2 2.x structure, that is the reason the output was incorrect.
>>DUMP form getimagesize () :
Array ( [0] => 10813680 [1] => 1572865 [2] => 6 [3] => width="10813680"
height="1572865" [bits] => 43373 [mime] => image/bmp )
>>DUMP from my own function, bmp_info () (identical to values that
given by WinXP properties and photoshop 7)
Array ( [width] => 240 [height] => 165 [planes] => 1 [bits] => 24
[bi_type] => Bitmap [bi_hsz] => 12 [bi_htype] => OS/2 1.x [ncolor] =>
16777216 [xdensity] => 96 [ydensity] => 96 [density_mod] => 1
[component] => 3 [compression] => 0 )
>>Header for bmp >= Windows 2.x and OS/2 1.x
typedef struct _WinBMPFileHeader, 14 bytes
{
WORD FileType;
DWORD FileSize;
WORD Reserved1;
WORD Reserved2;
DWORD BitmapOffset;
} WINBMPFILEHEADER;
Bitmap Windows 3.x should use this format, always 40 bytes
typedef struct tagBITMAPINFOHEADER{
DWORD biSize;
LONG biWidth;
LONG biHeight;
WORD biPlanes;
WORD biBitCount;
DWORD biCompression;
DWORD biSizeImage;
LONG biXPelsPerMeter;
LONG biYPelsPerMeter;
DWORD biClrUsed;
DWORD biClrImportant;
} BITMAPINFOHEADER, *PBITMAPINFOHEADER;
but Bitmap Windows 2.x and OS/2 1.x should read like this, and its
always 12 bytes
typedef struct _Win2xBitmapHeader
{
DWORD Size;
SHORT Width;
SHORT Height;
WORD Planes;
WORD BitsPerPixel;
} WIN2XBITMAPHEADER;
REFERENCE
http://netghost.narod.ru/gff/graphics/summary/os2bmp.htm
http://netghost.narod.ru/gff/graphics/summary/micbmp.htm
Windows BITMAPINFO-
http://msdn.microsoft.com/library/en-us/gdi/bitmaps_0zn6.asp?frame=true
Windows BITMAPINFOHEADER-
http://msdn.microsoft.com/library/en-us/gdi/bitmaps_1rw2.asp?frame=true
http://www.fastgraph.com/help/bmp_header_format.html
*please remove this message if outdated or solved
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Edit this bug report at http://bugs.php.net/?id=25581&edit=1
