Viola-Jones | Viola Jones implementation using CUDA | GPU library

Perhaps the biggest danger to Undefined Behaviour is not that it'll blow up in your face, but that it very, very often won't, and appears to be working fine until you change something else, such as running environment or hardware, the good old "it works on my machine" scenario; another UB area; or even nothing at all, such as a race condition.

Undefined Behaviour is not lazy terminology for a catastrophic error like segmentation fault or stackoverflow, nor a coy way of avoiding documentation for develop-specific errors. It may sometimes be a cop-out to examining a weird and technically incorrect code path, but ultimately undefined most often means inconsistent.

Check out this paper, seems exactly what you're looking for. You'll need a handle on VHDL or some hardware-description-language as well as some sort of breakout board like the Altera they are using.

Project Files and Source Code

Yes this is possible. For such a binary selection, it is easiest to use a bool argument:

It's hard to tell for sure, but are you trying to mark the face object as a lambda parameter? Then you need to switch parameters:

An alternative to detecting faces using Haar Cascades in OpenCV is to use a Histogram of Oriented Gradients feature detector. HOG-based object detectors can be used for detecting faces, and this is the technique used in some other image processing libraries such as Dlib. A Histogram of Oriented Gradients feature detector stores a 2D grid of local gradients and gradient directions of an image and compares this with a reference grid trained on a data set.