Image capturing from web camera

We are starting our introduction to advanced image processing with capturing the content from a video camera.

Capturing frame from the camera is be done in multiple steps:

1. Identifying the camera
2. Capturing the frame
3. Converting the frame to Julia images
4. Previewing the result

We will also find the most efficient way of getting the results to Julia images; that is, running the conversion process from C++ on a Julia side or saving and reloading the image.

First, we start by initializing libraries and configuration parameters:

ENV["PKG_CONFIG_PATH"] = "/Users/dc/anaconda/envs/python35/lib/pkgconfig"

using OpenCV
using Images
using Cxx

Next, we proceed with defining the function to convert Open CV images to Julia images:

function opencv_to_image(img_opencv)

    converted_image = zeros(Float16, (3, rows(img_opencv), 
     cols(img_opencv)));

    for i = 1:size(converted_image, 2)
        for j = 1:size(converted_image, 3)
            pixel_value = @cxx at_v3b(img_opencv...