• “The first step in calibration is to get snapshot images from all cameras.”
How do I get these dewarped snapshots and what are the resolutions needed?
A: in the deepstream_360_degree_smart_parking application, there is a model that transfers fish-eye images to dewarped images. For your only application, the “dewarped image” is the one that object detection and tracking are applied on. If you have a fish eye camera (like the 360 degree ones), probably you need to dewarp; If you have a regular camera (like a roadside traffic camera), probably you don’t need to dewarp. The calibration is to transfer the detected object location from camera domain to map domain so the first step is to get the snapshot images with the resolution that the detection will be applied on.
• And with QGIS, there’s this line “Make a note of the longitude and latitude of the origin (in this case, the center of the building).”
Does this mean that I have to get the coordinate of the center of the referenced TIF image?
A: The “global coordinates” don’t necessarily have to be the latitude and longitude. It can be any meaningful coordinates in the map domain with a user specified origin. In the cases where lat and long are not easy to get or are not optimal for the post analytics due to its scale, you may want to use your own “global coordinates” with user a specified origin. The origin doesn’t need to be the center of the maps of course.
• On the nvaisle/nvspot.csv files, what do ROI and the H values represent?
• How do I find the gx,gy coordinates? I tried just importing the latitute and longitude but they don’t work.
A: H values represent homography matrix, ideally the H values should not be part of the config files, they should be instantiated (during start) based on the values of the image and global coordinates mapping, however for ds-360 they were added as part of the config.
ROI are specific to aisle and parking spot.
gx, gy are part of the csv. [Relating to the Qs below on how to find gx, gy]. Please see header in the csv.
As above mentioned, H represents mapping from image to global plane. Each such mapping and ROI are camera specific.