Extract images and real world coordinates from OpenNI oni-files to OpenCV Matrices.
The OniExtractor class can be used to write frames extracted from a given .oni file to std::vector<cv::Mat>.
OniExtractor oe(filename);
bool ok = oe.init();
You can extract the RGB images (CV_8UC3), depth images (CV_16U),
real world coordinates (CV_32FU3) and timestamps (in milliseconds).
std::vector<cv::Mat> img, depth, world;
std::vector<unsigned long> ts;
oe.extract();
oe.getRGB(img);
oe.getDepth(depth);
oe.getWorldCoords(world);
oe.getTimestamps(ts);
Additionally you can specify timestamps of interest and a margin to extract only frames at the specified timestamps within the margin. Each time value is given in milliseconds.
std::vector<unsigned long> tsoi = {1000, 2000, 3000};
margin = 100;
oe.setTimestampsOfInterest(tsoi, margin);
If your timestamps of interest are absolute (i.e., Unix) timestamps, you can specify a reference time, e.g., the creation time of the .oni file.
unsigned long ref = 946684800000; // year 2000
oe.setAbsoluteTimestampReference(ref);
oe.setTimestampsOfInterest({946684801000, 946684802000, 946684803000}, 100);
... goes to Pieter Eendebak for this post, Dirk-Jan Kroon and M. Lang.