Using OpenCV from F#

Question

I would like to analyse the colour of a picture. Is it possible to use the OpenCV library with F# (the only language I am familiar with). If yes, do you know where I can find a tutorial/book on this subject (OpenCV 2 Computer Vision seems great but is written for C++ users).

Answer 1

This is definitely possible using F# with one of .NET wrappers over OpenCV. For example, below is the "Hello World" snippet that comes with EmguCV translated from C# to F# that works perfectly:

open Emgu.CV
open Emgu.CV.CvEnum
open Emgu.CV.Structure

[<EntryPoint>]
let main(_) =
    let win1 = "Test Window"
    CvInvoke.cvNamedWindow(win1) |> ignore
    use img = new Image<Bgr, byte>(400, 200, Bgr(255.,0.,0.))
    let f = ref (MCvFont(FONT.CV_FONT_HERSHEY_COMPLEX, 1., 1.))
    img.Draw("Hello, World", f, System.Drawing.Point(10,80), Bgr(0.,255.,0.))
    CvInvoke.cvShowImage(win1, img.Ptr)
    CvInvoke.cvWaitKey(0) |> ignore
    CvInvoke.cvDestroyWindow(win1)
    0

EmguCV web site and installation provide some C# tutorials that may give you initial traction. Your mileage may vary, depending on your F# interop skills among other factors.

Answer 2

Emgu CV is the most popular option with Emgu CV Essentials book. Two other .NET OpenCV wrapper projects:

• OpenCvSharp
• OpenCV.NET