OpenCV Python 3.3

Question

I have Python 3.3 and 2.7 installed on my computer

For Python 3.3, I installed many libraries like numpy, scipy, etc

Since I also want to use opencv, which only supports python 2.7 so far, I installed opencv under Python 2.7.

Hey, here comes the problem, what if I want to import numpy as well as cv in the same script?

Answer 1

You'll have to install all the libraries you want to use together with OpenCV for Python 2.7. This is not much of a problem, you can do it with pip in one line, or choose one of the many pre-built scientific Python packages.

Answer 2

"Hey, here comes the problem, what if I want to import numpy as well as cv in the same script?"

As far as python 2.7 goes, numpy and cv can be imported in the same script. In fact opencv accepts numpy arrays. Please see the code below

import os
import numpy as np
import cv2


def processImage(dirName, imgName):
    imgFilepath = os.path.join(dirName, imgName)
    img = cv2.imread(imgFilepath)
    print imgName, img.size
    #convert img to a numpy array
    numpyImg = np.asarray(img)
    #use as inout to cv2 call
    #this converts a color imageto a grayscale image
    grayscaleImg = cv2.cvtColor(numpyImg, cv2.COLOR_BGR2GRAY)
    (fname, ext) = os.path.splitext(imgName)
    outImgName = fname + '_gray' + ext
    #write grayscalimage
    cv2.imwrite(os.path.join(dirName, outImgName), grayscaleImg)
    pass

def main():
    #aphid1_small.jpg is a rgb image
    imgName = "aphid1_small.jpg"
    dirName = "data"
    processImage(dirName, imgName)

if __name__ == "__main__":
    main()
    pass