python PIL YCbCr 支持

Question

尝试在 YCbCr 模式下创建 PIL 镜像甚至会在我的 ubuntu 11.04 中从 synaptic 安装新的 python/PIL 时崩溃

wim@wim-ubuntu:~$ python
Python 2.7.1+ (r271:86832, Apr 11 2011, 18:13:53) 
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import Image
>>> Image.VERSION
'1.1.7'
>>> Image.new('YCbCr', (640,480))
*** buffer overflow detected ***: python terminated
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(__fortify_fail+0x37)[0x7f4a35e4a1d7]
/lib/x86_64-linux-gnu/libc.so.6(+0xfd0f0)[0x7f4a35e490f0]
/usr/local/lib/python2.7/dist-packages/PIL/_imaging.so(ImagingNewPrologueSubtype+0x97)[0x7f4a34bfb257]
/usr/local/lib/python2.7/dist-packages/PIL/_imaging.so(ImagingNewBlock+0xb)[0x7f4a34bfb78b]
/usr/local/lib/python2.7/dist-packages/PIL/_imaging.so(ImagingNew+0x4c)[0x7f4a34bfb86c]
/usr/local/lib/python2.7/dist-packages/PIL/_imaging.so(+0xfd22)[0x7f4a34bddd22]
python(PyEval_EvalFrameEx+0x361)[0x4965f1]
python(PyEval_EvalCodeEx+0x145)[0x49d325]
python(PyEval_EvalFrameEx+0x802)[0x496a92]
python(PyEval_EvalCodeEx+0x145)[0x49d325]
python(PyEval_EvalCode+0x32)[0x4ecb02]
python[0x4fdc74]
python(PyRun_InteractiveOneFlags+0x1e2)[0x42cd9e]
python(PyRun_InteractiveLoopFlags+0xc0)[0x42cebd]
python(PyRun_AnyFileExFlags+0x39)[0x42d2e1]
python(Py_Main+0xac9)[0x418c9e]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xff)[0x7f4a35d6aeff]
python[0x4c62b1]
======= Memory map: ========
00400000-0062f000 r-xp 00000000 08:21 1049585                            /usr/bin/python2.7
0082e000-0082f000 r--p 0022e000 08:21 1049585                            /usr/bin/python2.7
0082f000-00897000 rw-p 0022f000 08:21 1049585                            /usr/bin/python2.7
00897000-008a9000 rw-p 00000000 00:00 0 
01f0a000-021a1000 rw-p 00000000 00:00 0                                  [heap]
7f4a34794000-7f4a347a9000 r-xp 00000000 08:21 659235                     /lib/x86_64-linux-gnu/libgcc_s.so.1
7f4a347a9000-7f4a349a8000 ---p 00015000 08:21 659235                     /lib/x86_64-linux-gnu/libgcc_s.so.1
7f4a349a8000-7f4a349a9000 r--p 00014000 08:21 659235                     /lib/x86_64-linux-gnu/libgcc_s.so.1
7f4a349a9000-7f4a349aa000 rw-p 00015000 08:21 659235                     /lib/x86_64-linux-gnu/libgcc_s.so.1
7f4a349aa000-7f4a349cd000 r-xp 00000000 08:21 1057568                    /usr/lib/x86_64-linux-gnu/libjpeg.so.62.0.0
7f4a349cd000-7f4a34bcc000 ---p 00023000 08:21 1057568                    /usr/lib/x86_64-linux-gnu/libjpeg.so.62.0.0
7f4a34bcc000-7f4a34bcd000 r--p 00022000 08:21 1057568                    /usr/lib/x86_64-linux-gnu/libjpeg.so.62.0.0
7f4a34bcd000-7f4a34bce000 rw-p 00023000 08:21 1057568                    /usr/lib/x86_64-linux-gnu/libjpeg.so.62.0.0
7f4a34bce000-7f4a34c0b000 r-xp 00000000 08:21 1312337                    /usr/local/lib/python2.7/dist-packages/PIL/_imaging.so
7f4a34c0b000-7f4a34e0b000 ---p 0003d000 08:21 1312337                    /usr/local/lib/python2.7/dist-packages/PIL/_imaging.so
7f4a34e0b000-7f4a34e0e000 r--p 0003d000 08:21 1312337                    /usr/local/lib/python2.7/dist-packages/PIL/_imaging.so
7f4a34e0e000-7f4a34e11000 rw-p 00040000 08:21 1312337                    /usr/local/lib/python2.7/dist-packages/PIL/_imaging.so
7f4a34e11000-7f4a34e30000 r-xp 00000000 08:21 1316665                    /usr/lib/python2.7/lib-dynload/_ctypes.so
7f4a34e30000-7f4a3502f000 ---p 0001f000 08:21 1316665                    /usr/lib/python2.7/lib-dynload/_ctypes.so
7f4a3502f000-7f4a35030000 r--p 0001e000 08:21 1316665                    /usr/lib/python2.7/lib-dynload/_ctypes.so
7f4a35030000-7f4a35034000 rw-p 0001f000 08:21 1316665                    /usr/lib/python2.7/lib-dynload/_ctypes.so
7f4a35034000-7f4a35035000 rw-p 00000000 00:00 0 
7f4a35035000-7f4a35075000 r-xp 00000000 08:21 655419                     /lib/libncurses.so.5.7
7f4a35075000-7f4a35274000 ---p 00040000 08:21 655419                     /lib/libncurses.so.5.7
7f4a35274000-7f4a35278000 r--p 0003f000 08:21 655419                     /lib/libncurses.so.5.7
7f4a35278000-7f4a35279000 rw-p 00043000 08:21 655419                     /lib/libncurses.so.5.7
7f4a35279000-7f4a352b2000 r-xp 00000000 08:21 655450                     /lib/libreadline.so.6.2
7f4a352b2000-7f4a354b2000 ---p 00039000 08:21 655450                     /lib/libreadline.so.6.2
7f4a354b2000-7f4a354b4000 r--p 00039000 08:21 655450                     /lib/libreadline.so.6.2
7f4a354b4000-7f4a354ba000 rw-p 0003b000 08:21 655450                     /lib/libreadline.so.6.2
7f4a354ba000-7f4a354bb000 rw-p 00000000 00:00 0 
7f4a354bb000-7f4a354c0000 r-xp 00000000 08:21 1316693                    /usr/lib/python2.7/lib-dynload/readline.so
7f4a354c0000-7f4a356bf000 ---p 00005000 08:21 1316693                    /usr/lib/python2.7/lib-dynload/readline.so
7f4a356bf000-7f4a356c0000 r--p 00004000 08:21 1316693                    /usr/lib/python2.7/lib-dynload/readline.so
7f4a356c0000-7f4a356c2000 rw-p 00005000 08:21 1316693                    /usr/lib/python2.7/lib-dynload/readline.so
7f4a356c2000-7f4a35d4c000 r--p 00000000 08:21 1055991                    /usr/lib/locale/locale-archive
7f4a35d4c000-7f4a35ed6000 r-xp 00000000 08:21 659207                     /lib/x86_64-linux-gnu/libc-2.13.so
7f4a35ed6000-7f4a360d5000 ---p 0018a000 08:21 659207                     /lib/x86_64-linux-gnu/libc-2.13.so
7f4a360d5000-7f4a360d9000 r--p 00189000 08:21 659207                     /lib/x86_64-linux-gnu/libc-2.13.so
7f4a360d9000-7f4a360da000 rw-p 0018d000 08:21 659207                     /lib/x86_64-linux-gnu/libc-2.13.so
7f4a360da000-7f4a360e0000 rw-p 00000000 00:00 0 
7f4a360e0000-7f4a36164000 r-xp 00000000 08:21 659244                     /lib/x86_64-linux-gnu/libm-2.13.so
7f4a36164000-7f4a36363000 ---p 00084000 08:21 659244                     /lib/x86_64-linux-gnu/libm-2.13.so
7f4a36363000-7f4a36364000 r--p 00083000 08:21 659244                     /lib/x86_64-linux-gnu/libm-2.13.so
7f4a36364000-7f4a36365000 rw-p 00084000 08:21 659244                     /lib/x86_64-linux-gnu/libm-2.13.so
7f4a36365000-7f4a3637c000 r-xp 00000000 08:21 659290                     /lib/x86_64-linux-gnu/libz.so.1.2.3.4
7f4a3637c000-7f4a3657b000 ---p 00017000 08:21 659290                     /lib/x86_64-linux-gnu/libz.so.1.2.3.4
7f4a3657b000-7f4a3657c000 r--p 00016000 08:21 659290                     /lib/x86_64-linux-gnu/libz.so.1.2.3.4
7f4a3657c000-7f4a3657d000 rw-p 00017000 08:21 659290                     /lib/x86_64-linux-gnu/libz.so.1.2.3.4
7f4a3657d000-7f4a366e3000 r-xp 00000000 08:21 655398                     /lib/libcrypto.so.0.9.8
7f4a366e3000-7f4a368e3000 ---p 00166000 08:21 655398                     /lib/libcrypto.so.0.9.8
7f4a368e3000-7f4a368f0000 r--p 00166000 08:21 655398                     /lib/libcrypto.so.0.9.8
7f4a368f0000-7f4a36909000 rw-p 00173000 08:21 655398                     /lib/libcrypto.so.0.9.8
7f4a36909000-7f4a3690c000 rw-p 00000000 00:00 0 
7f4a3690c000-7f4a36958000 r-xp 00000000 08:21 655454                     /lib/libssl.so.0.9.8Aborted
wim@wim-ubuntu:~$ 

我已经尝试过

find /usr -name Image.py | xargs grep -n YCbCr 

并找到了我认为有问题的行

216:    "YCbCr": ('|u1', 4),

YCbCr 图像应该是 3 channel ，而不是 4。我将其更改为 3 并删除了 .pyc，但是当代码进入 c 代码时仍然以相同的方式崩溃(core.fill with mode='YCbCr' )。好吧，所以我想也许这个错误以某种方式进入了构建，在包管理器中标记了 PIL 以完全删除，下载了源代码、依赖项，并将数字 4 修改为 3，经过一些路径的修改后，能够再次构建 PIL，所有自检都通过，然后安装。不幸的是，仍然是同样的崩溃。现在我不知道该怎么办 - 我需要 PIL 中的 YCbCr 颜色空间支持，但无法修复该错误。

编辑:也许这可以提供进一步的见解，我发现虽然 Image.new('YCbCr', (640,480))在 10.10 中没有崩溃，可以使用 numpy.asarray(Image.new('YCbCr', (640,480))) 引发段错误。 。这一切听起来像是 numpy 和/或 PIL 的某些 C 扩展中的内存问题，或者它们彼此交谈的方式的问题。

Answer 1

追根溯源，似乎是strcpy()在libImaging/Storage.c:186这导致了缓冲区溢出。进一步查看代码，我发现 im->mode不够大，无法容纳"YCbCr" .

要解决这个问题，只需更改 libImaging/Imaging.h:78来自char mode[4+1];至 <罢工> char mode[4+2]; char mode[6+1];并重新编译PIL。

对于numpy.asarray ，根据another post ，我认为这也是 PIL 的问题以及您对 Image.py 的修复应该可以。

编辑:之前提交了 Fedora 补丁，建议更改为 char mode[6+1];所以缓冲区足够大，可以容纳 "RGB;32" .

OOT:如果Linus would see this由于它的魔力，他肯定不会接受我的修复..