Hello everybody,
I have extracted some points using OpenCV from video. The imager esolution is ( 640X 480). The extracted coordinates are in pixel coordinates i.e. it looks like follows:

(x, y) : ( 403, 303)
(x, y): (414, 297)

Etc..


Now I would like to display the coordinates in 3D space using OpenGL. I know I need some transformation which involves rotation and translation for conversion from OpenCV to OpenGL pixel coordinates.

In my OpenGL, I also made the window resolution ( 640X480).

Now after transformation of pixel coordinates from OpenCV to OpenGL workspace, I need to display them in 3D object coordinate. Could any one let me know what I have to do for that purpose?

Thanks in advance.

Hi, I am getting the points in pixel, but I would like to draw in coordinates using glVertex3d( x , y, z); What is the easiest way to convert to coordinates from points? Do I need to do texture mapping for this? Please give me some suggestions.

I think they're asking for unprojection, though that would probably require a depth value to have any meaningful third dimension.

Are you just trying to show the video on the screen using OpenGL? - Or why do you wish to use 3D ?

If you do wish to only display the video, you should just do it in 2D, set up your scene with gluOrtho2D (or equivalent depending on version )

Enable Texturing, load your information into the texture, and draw a textured Quad.

I worked on my final year project in college using something similar to this, i was allowed to use OpenCV to get information from the webcam, but that was all - and as far as i remember, the information would be given to you in the format : ptr* char array[640x480x3] { .. r,g,b,r,g,b ... } - using this information you can build a Bitmap, then use that Bitmap for your texture.

If you really want it in 3d for some reason - do what i said above, and just draw your quad at glVertex3f( x, y, z );

Hi, I fixed that problem, Just try to identify the screen resolution in OpenGL workspace and did some translation for proper mapping. Thanks for the advice.