diff --git a/modules/matlab/README.md b/modules/matlab/README.md index 1167a5e0e1..c909af75a7 100644 --- a/modules/matlab/README.md +++ b/modules/matlab/README.md @@ -42,7 +42,7 @@ to get help on the purpose and call signature of a particular method, or to get general help regarding the OpenCV bindings. If you ever run into issues with the bindings - cv.buildInformation(); + cv.buildInformation(); will produce a printout of diagnostic information pertaining to your particular build of OS, OpenCV and Matlab. It is useful to submit this information alongside a bug report to the OpenCV team. @@ -52,46 +52,48 @@ The Matlab bindings come with a set of utilities to help you quickly write your The first thing you need to learn how to do is write a mex-file with Matlab constructs. Following is a brief example: - // include useful constructs - // this automatically includes opencv core.hpp and mex.h) - #include - using namespace cv; - using namespace std; - - // define the mex gateway - void mexFunction(int nlhs, mxArray* plhs[], - int nrhs, const mxArray* prhs[]) { - - // claim the inputs into scoped management - MxArrayVector raw_inputs(prhs, prhs+nrhs); - - // add an argument parser to automatically handle basic options - ArgumentParser parser("my function"); - parser.addVariant(1, 1, "opt"); - MxArrayVector parsed_inputs = parser.parse(inputs); - - // if we get here, we know the inputs are valid. Unpack... - BridgeVector inputs(parsed_inputs); - Mat required = inputs[0].toMat(); - string optional = inputs[1].empty() ? "Default string" : inputs[1].toString(); - - try { - // Do stuff... - } catch(Exception& e) { - error(e.what()); - } catch(...) { - error("Uncaught exception occurred"); - } - - // allocate an output - Bridge out = required; - plhs[0] = out.toMxArray().releaseOwnership(); - } +```cpp +// include useful constructs +// this automatically includes opencv core.hpp and mex.h) +#include +using namespace cv; +using namespace std; + +// define the mex gateway +void mexFunction(int nlhs, mxArray* plhs[], + int nrhs, const mxArray* prhs[]) { + + // claim the inputs into scoped management + MxArrayVector raw_inputs(prhs, prhs+nrhs); + + // add an argument parser to automatically handle basic options + ArgumentParser parser("my function"); + parser.addVariant(1, 1, "opt"); + MxArrayVector parsed_inputs = parser.parse(inputs); + + // if we get here, we know the inputs are valid. Unpack... + BridgeVector inputs(parsed_inputs); + Mat required = inputs[0].toMat(); + string optional = inputs[1].empty() ? "Default string" : inputs[1].toString(); + + try { + // Do stuff... + } catch(Exception& e) { + error(e.what()); + } catch(...) { + error("Uncaught exception occurred"); + } + + // allocate an output + Bridge out = required; + plhs[0] = out.toMxArray().releaseOwnership(); +} +``` There are a couple of important things going on in this example. Firstly, you need to include `` to enable the bridging capabilities. Once you've done this, you get some nice utilities for free. `MxArray` is a class that wraps Matlab's `mxArray*` class in an OOP-style interface. `ArgumentParser` is a class that handles default, optional and named arguments for you, along with multiple possible calling syntaxes. Finally, `Bridge` is a class that allows bidirectional conversions between OpenCV/std and Matlab types. Once you have written your file, it can be compiled with the provided mex utility: - + cv.mex('my_function.cpp'); This utility automatically links in all of the necessary OpenCV libraries to make your function work.