LibOpenCV.jl

Julia bindings for OpenCV.

Installation

Unix (Ubuntu and Mac OSX)

Install OpenCV, then:

Pkg.clone("https://github.com/abhijithch/LibOpenCV.jl")
Pkg.build("LibOpenCV")

Windows

Download or build the MinGW 64-bit binaries of OpenCV and add the bin directory to PATH environment variable.

Clone the package from julia prompt.

Pkg.clone("https://github.com/abhijithch/LibOpenCV.jl")

Add deps/windows directory to the PATH environment variable.

Minimal Example -- Calculate histogram

The code of calculating histogram that use OpenCV Julia binding is like this:

include("../src/OpenCV.jl")

img = cv2.imread("/home/sun/workspace/Lena.jpg")

# split image by each channel
images = cv2.split(img)

# make an empty image to draw histogram
histImage = cv2.zeros(300, 256, cv2.matType(img))

# prepare the x coordinate of each bin
bins = reshape(1:256, 256)

#Three color of BGR
color = [ (255,0,0),(0,255,0),(0,0,255) ]

# draw the histogram for each channel by cv.polylines
for i = 1:3
    # calculate histogram for each channel
    hist = cv2.calcHist([images[i]], [0], [256], [0.0, 255.0])
    # an custom function, normarlize the hist value to 0-255
    hist = cv2.normarlizeT(hist)
    # make the histogram draw in image from down to top
    for j = 1:length(hist)
        hist[j] = 300 - hist[j]
    end
    # stack two array by column, I don't know whether there has
    # similar function in Julia
    pts = cv2.columnStack(bins, hist)
    # draw each hist, represent to a polyline
    cv2.polylines(histImage, pts, false, color[i])
end

cv2.imshow("HistImage", histImage)
cv2.waitKey(0)

Here is the output that generated in Julia by the binding: