For Bug #3714, user use the imshow() function without calling
namedWindow() properly, because user did not know the implicit rule for
imshow(). (i.e. without calling namedWindow implied calling namedWindow(
,CV__WINDOW_AUTOSIZE).
Improve the Display Image Tutorial to educate the user for such implied
rule.
Put a note on documentation for Bug#3714
Revise the documentation regarding to imshow() function to better
educate the user the implicit rule. (i.e. without creating the window
before the imshow() function is the same as creating AUTOSIZE window)
ContextImpl::currentContext contains a reference to one of the
DeviceInfoImpl objects from:
static std::vector<DeviceInfoImpl> global_devices;
ContextImpl::currentContext is destroyed in the destructor
for the statically defined object __module, and relies on its
DeviceInfoImpl reference to query some hardware features while
being destroyed.
This means that we need to ensure that the global_devices vector is
destroyed affter __module, otherwise ContextImpl::currentContext's
DeviceInfoImpl reference will no longer be valid when __module is
destroyed.
Since these variables are all confined to a single compilation unit,
they will be destruct from bottom to top, so we need to make sure
that __module is the bottom definition so it can be destroyed first.
This bug was triggered by Buildroot autobuilders [1,2], causing this
kind of failures [3,4]:
[ 14%] Building CXX object modules/core/CMakeFiles/opencv_core.dir/src/system.cpp.o
/home/test/autobuild/instance-0/output/build/opencv-2.4.10/modules/core/src/system.cpp: In function '(static initializers for /home/test/autobuild/instance-0/output/build/opencv-2.4.10/modules/core/src/system.cpp)':
/home/test/autobuild/instance-0/output/build/opencv-2.4.10/modules/core/src/system.cpp:280:10: error: inconsistent operand constraints in an 'asm'
make[3]: *** [modules/core/CMakeFiles/opencv_core.dir/src/system.cpp.o] Error 1
[1] http://buildroot.org/
[2] http://autobuild.buildroot.org/
[3] http://autobuild.buildroot.org/?reason=opencv-2.4.10
[4] http://autobuild.buildroot.org/results/483/4838285b25d6293a5cf0bb9eadd5040a7c75d766/build-end.log
Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Fixed the non-working code example for NAryMatIterator.
The documentation of NAryMatIterator in file:
modules/core/include/opencv2/core/core.hpp has a working example which
was used for these edits.
