Nimbus-C

Introduction

Here you can find our prepared Raspberry Pi OS (buster) images. Furthermore here is the official documentation.

Adding a custom processing stage

C-Interface

After having built and installed nimbus-userland (make install), all libraries are installed under /usr/local/lib, all headers are installed under /usr/local/include The header nimbusPreprocessInterface.h contains a low level c interface to libnimbus-preprocessing.so. This is useful when you want to integrate the nimbus 3d with external applications.

The following example (src/main.cpp) shows a basic implemenation to get the image data in C/C++; It is important to understand, that this implementation directly integrates into the preprocessing toolchain. Therefore, it is triggered synchronous and any runtime inside the callback will reduce the overall framerate!

Get the image data

The following Interface is being used to access the image and point cloud data. The image data is contained in a 1D array. 352*286 pixels.

uint16_t* ampl      = nimbus_seq_get_amplitude(img);   //Amplitude/Intensity of the pixels
uint8_t* conf       = nimbus_seq_get_confidence(img);  //Confidence Matrix showing the exposure state
uint16_t* radial    = nimbus_seq_get_radial_dist(img); //Radial Distance of the Measurement
int16_t* x          = nimbus_seq_get_x(img);           //X Position of all pixels
int16_t* y          = nimbus_seq_get_y(img);           //Y Position of all pixels
int16_t* z          = nimbus_seq_get_z(img);           //Z Position of all pixels
ImgHeader_t* header = nimbus_seq_get_header(img);

Exposure

It is also possible to change the exposure setting inside your c/c++ application Use the following API for this.

AutoExposureParams_t m_params;
m_params.amplitude     = amplitude;     //0.0 - ~1500.0  <-- desired amplitude for auto exposure
m_params.max_exposure  = max_exposure;  //0-32767  <-- exposure limit for auto, also functions as exposure value for manual exposure 
m_params.hdr_factor    = hdr_factor;    //0.0 - 1.0   <-- dertermines the dynamic range
m_params.exposure_mode = exposure_mode; //MANUAL = 0, MANUAL_HDR  = 1, AUTO = 2, AUTO_HDR = 3
bool set_exposure = nimbus_autoexposure_set_params(&m_params);

Run the example

1.) Create a build folder

mkdir build
cd build

2.) Run Cmake

cmake ..
make all

3.) Run the compiled program

./nimbus-c