1. Default Constructed Return Value: return {}

    It is common for C/C++ functions to return default values, for example, if some internal condition fails. This is straightforward for native return types, as in: …


  2. Drawing Arrows with OpenCV

    Here’s a little OpenCV gem I found. OpenCV has a (relatively) new function (post-2.4.9) called cv::arrowedLine() that let’s you draw a one directional arrow between 2 points. …


  3. Horizontal Matrix Concatenation in OpenCV

    Here’s a little undocumented function to horizontally concatenate two cv::Mat matrices (with the same number of rows). …