topic ColorToDepth does not need in Software Archive

Image to color coordinates vector

Alessio_X_ — Mon, 07 Sep 2015 14:33:45 GMT

Hi folks,

I am learning how to use the SDK for R200 and I am trying to obtain 3D world coordinates.
I got how to use QueryVertices() function from a depth image, but I would like to map color coordinates with depth coordinates to correctly parse pixels in my image. Following the Projection sample, I am going to use ColorToDepth(), but I am missing the vector of color coordinates and I don't know how to construct from the PXCImage sample->color. Based on my knowledge of images as matrices in MatLab, I was thinking of creating a vector by concatenating over columns, isn't it?

Thank you in advance.

ColorToDepth does not need

Xusheng_L_Intel — Thu, 24 Sep 2015 18:10:00 GMT

ColorToDepth does not need the color image but the color x, y values. It requires the depth image from the camera (which contains the depth data as well as the camera calibration parameters.) Did I answer your question? Thanks!

Hey David, that sounds

samontab — Fri, 25 Sep 2015 04:16:24 GMT

Hey David, that sounds interesting!

So, the depth image produced by the camera not only contains the depth information, but also the camera calibration parameters? I didn't know that! I assumed those parameters were unavailable at the library level.

Where are these parameters stored? in the image metadata? Do you have any pointer for more information on this?

Hi Alessio,

jb455 — Fri, 25 Sep 2015 08:44:42 GMT

Hi Alessio,

You need to pass the ColourToDepth projection an array of points you're interested in, so if you only want to know about a single point you can pass it an array containing that one point; or if you want to project the whole colour image you'll have to loop through all pixels in the colour image and construct an array containing each point (ie, for x = 0 to width, for y = 0 to height, array.push(x,y)). Beware though, projecting each pixel in a 640*480 image takes over 60 seconds to process on my PC - if you're using a higher res image this will take even longer.You may be better off singly projecting each point as you need it.

Hope this helps!
James