what is meant create header without allocated in memory c++

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OpenCV

what is meant create header without allocated in memory c++
{ cvCreateMatHeader() ,cvCreateData()}

Posted 2-Aug-13 11:13am

Anderso0on

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Sergey Alexandrovich Kryukov · Answer 1 · 2013-08-02T11:28:00

Solution 1

It simply means that only the CvMat object is allocated and created, but not actual matrix data (not memory for the elements of the matrix themselves), which you can allocate and add later. The instance of this class without actual data still carries metadata: in this case, just the dimension of the array container and element type descriptor. One purpose of this is to allow the user-allocated data.

Please see: http://opencv.willowgarage.com/documentation/operations_on_arrays.html[^].

—SA

Posted 2-Aug-13 11:28am

Sergey Alexandrovich Kryukov

v2

Comments

Anderso0on 2-Aug-13 17:43pm

pleace give me example about data and header

Sergey Alexandrovich Kryukov 2-Aug-13 18:12pm

Example of what? The documentation is quite clear...
—SA

Anderso0on 2-Aug-13 17:46pm

and what is different between this fun
cvCreateMat()
cvCreateMatHeader()
cvMat()
cvInitMatHeader()

Sergey Alexandrovich Kryukov 2-Aug-13 18:15pm

Did anyone ever taught you that the questions about "difference" are incorrect?!
What's the use? You can read about each of the functions separately and understand what do they supposed to do. That's all that matter.
Besides, if you did not manage to figure out what one function does after my explanation and supposedly reading the documentation, how can I hope that you are going to understand others. Please, one step at a time. If you have some particular concern, please ask...
—SA