If you wish to use CV2, you need to use the resize
function.
For example, this will resize both axes by half:
small = cv2.resize(image, (0,0), fx=0.5, fy=0.5)
and this will resize the image to have 100 cols (width) and 50 rows (height):
resized_image = cv2.resize(image, (100, 50))
Another option is to use scipy
module, by using:
small = scipy.misc.imresize(image, 0.5)
There are obviously more options you can read in the documentation of those functions (cv2.resize, scipy.misc.imresize).
Update:
According to the SciPy documentation:
imresize
is deprecated in SciPy 1.0.0, and will be removed in 1.2.0.
Useskimage.transform.resize
instead.
Note that if you're looking to resize by a factor, you may actually want skimage.transform.rescale
.