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2015-10-01 09:41:43 -0500 asked a question perspective transformation with given camera pose

Hi everyone!

I'm trying to create a program, that I will use to perform some tests.

In this program an 2D image is being displayed in 3D space in the cv:viz window, so user can change camera (viewer) position and orientation.

image description

After that, program stores camera pose and takes the snaphot of the current view (without coordinates axes):

image description

An here is the goal:

I have the snaphot (perspective view of undetermined plane or part of the plane), camera pose (especially its orientation) and camera parameters. Using these given values I would like to perform perspective transformation to compute an ortographic view of this given image (or its visible part).

I can get the camera object and compute its projection matrix:


and then decompose projection matrix:

decomposeProjectionMatrix(subProjMatrix,cameraMatrix, rotMatrix, transVect, rotMatX, rotMatY, rotMatZ);

And what should I do next? Notice, that I can't use chessboard cornersbecause the image is undetermined (it may be any image) and I can't use the corner points of the image, because user can zoom and translate the camera, so there is posibility, that no image corner point will be visible...

Thanks for any help in advance!

2015-03-25 05:44:24 -0500 received badge  Supporter (source)
2015-03-25 03:41:38 -0500 commented question opencv_objdetect300.dll - Access violation reading location

Thanks a lot, Steven!

I updated cascadedetect.hpp and cascadedetect.cpp files ( and now everything works both on CPU and GPU, and both in release and debug modes.


2015-03-24 09:00:02 -0500 asked a question opencv_objdetect300.dll - Access violation reading location

Hi everyone!

I tried to run Haar-like feature detection example code ( I have modified it a little bit (I changed the image source from video to static image) and succesfully built it (both in release and debug). Program starts properly, image is beeing read and then, while processing, error occures:

Unhandled exception at 0x000007FEF2622C1B (opencv_objdetect300.dll) in Project1.exe: 0xC0000005: Access violation reading location 0xFFFFFFFEF35FC3B8

Program breaks inside following function in cascadedetect.hpp header file:

inline float HaarEvaluator::OptFeature :: calc( const int* ptr ) const

I use Visual Studio 2012 PRO on Windows 7 x64. Opencv 3.00 has been built from source.

May anyone help me? Thanks in advance!