title: combine two pictures(different size) horizontally?
body: <p>I have 2 pictures, need to combine them horizontally. I know numpy and cv2(opencv) should help me to do this. But don't know how.
  I used img1 = cv2.imread(file1), img2 = cv2.imread(file2)
  the 2 images' shape are (2048, 1334, 3) and (720, 1200, 3)
  How could I do this? when I open These 2 images, they have similar height, different width.
  I only know if the 2 pics have the same size, then just use concate, but my 2 pics are different sizes. 
  For the final output, I want to have them keep their own width, height choose the biggest/smallest...
  So I imagine the final output should maybe 2/3 width one picture, 1/3 width the other pic which is totally good. I don't need these 2 are evenly distributed. Just keep their own width. Thanks!</p>