#2 Using large image will crash the DLL

[Anonymous]

Hi,
If you try to call "GetKeypoints( );" with a large image, the DLL will crash without any message. The bug is present from version 1.0 until 1.2 included!

Are you aware of this behavior?
Smaller images (2000px x 3000px) will also crash.

Regards

[Anonymous]

[zerofrog]

there was a couple of problems, i think i fixed them in revision 50. can you check out the sources from svn, compile, if it still crashes, you most likely need to add more memory to your machine.

[Anonymous]

Unfortunately, it does not solve the issue :
1) on Windows, with Visual Studio 2005 the following errors appear when compiling the SVN revision 50:
1>------ Build started: Project: libsiftfast-static, Configuration: Release Win32 ------
1>Compiling...
1>libsiftfast.cpp
1>..\libsiftfast.cpp(267) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
1>..\libsiftfast.cpp(268) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
1>..\libsiftfast.cpp(384) : error C3861: 'log2': identifier not found
1>..\libsiftfast.cpp(389) : error C2228: left of '.push_back' must have class/struct/union
1>..\libsiftfast.cpp(389) : error C3861: 'log2': identifier not found
1>..\libsiftfast.cpp(551) : error C3016: 'ikey' : index variable in OpenMP 'for' statement must have signed integral type
1>Build log was saved at "file://u:\libsiftfast-1.2Build50-src\build\libsiftfast-static.dir\Release\BuildLog.htm"
1>libsiftfast-static - 4 error(s), 2 warning(s)
========== Build: 0 succeeded, 1 failed, 1 up-to-date, 0 skipped ==========

I had to write my own "log2" function.
I had to declare the OPEN_MP for loop with "long long" instead of "unsigned int".

2) I changed you file in order to make it run correctly :
see attached file!

1>------ Build started: Project: libsiftfast-static, Configuration: Release Win32 ------
1>Building Custom Rule U:/Programmation/libSIFTFast_LPM/libsiftfast-1.2Build50-src/CMakeLists.txt
1>CMake does not need to re-run because CMakeFiles/generate.stamp is up-to-date.
1>Compiling...
1>libsiftfast.cpp
1>..\libsiftfast.cpp(277) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
1>..\libsiftfast.cpp(278) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
1>..\libsiftfast.cpp(394) : warning C4244: 'argument' : conversion from 'double' to 'unsigned int', possible loss of data
1>..\libsiftfast.cpp(562) : warning C4244: 'argument' : conversion from '__int64' to 'unsigned int', possible loss of data
1>..\libsiftfast.cpp(563) : warning C4244: 'argument' : conversion from '__int64' to 'unsigned int', possible loss of data
1>..\libsiftfast.cpp(564) : warning C4244: 'argument' : conversion from '__int64' to 'unsigned int', possible loss of data
1>..\libsiftfast.cpp(565) : warning C4244: 'argument' : conversion from '__int64' to 'unsigned int', possible loss of data
1>Creating library...
1>Build log was saved at "file://\libsiftfast-1.2Build50-src\build\Release\BuildLog.htm"
1>libsiftfast-static - 0 error(s), 7 warning(s)
========== Build: 1 succeeded, 0 failed, 1 up-to-date, 0 skipped ==========

3) The machine has 3Go of RAM. It does not seems to be a problem of RAM that causes the crash.

4) Even though, the "GetKeypoints( );" crashes...

[Anonymous]

the modification to make it run under VisualStudio 2005

[zerofrog]

thanks! i committed your changes.
it looks like the crash is occuring inside openmp when writing an sse register to a 0 memory address, i was conveniently assuming it was due to a out-of-memory issue...
another likely possibility is that openmp is using the stack space for storing the local image, and it is exhausting this...

[zerofrog]

On further inspection, the memory allocation is failing. basically i get 8 fails of 500M each on a machine with 3GB RAM. Perhaps you might want to consider testing on a x64 machine. i added error messages in r52