How to crop OpenCV Image from center
Question:
How can I crop an image using OpenCV from the center?
I think it has something to do with this line, but if there is a better way please inform me.
crop_img = img[y:y+h, x:x+w]
Answers:
The line you provided crops the image region located at (x,y) with (w,h) width and height. Not sure if this is around the center of the image.
To crop (w,h) region around the center you have to do the following:
center = image.shape / 2
x = center[1] - w/2
y = center[0] - h/2
and only then
crop_img = img[y:y+h, x:x+w]
Just an additional comment for the Lenik’s answer (It is the first time I want to contribute in StackOverflow and don’t have enough reputation to comment the answer), you need to be sure x and y are integers.
Probably in this case x and y would always be integers as most of resolutions are even, but is a good practice to keep the values inside an int().
center = image.shape / 2
x = center[1] - w/2
y = center[0] - h/2
crop_img = img[int(y):int(y+h), int(x):int(x+w)]
How can I crop an image using OpenCV from the center?
I think it has something to do with this line, but if there is a better way please inform me.
crop_img = img[y:y+h, x:x+w]
The line you provided crops the image region located at (x,y) with (w,h) width and height. Not sure if this is around the center of the image.
To crop (w,h) region around the center you have to do the following:
center = image.shape / 2
x = center[1] - w/2
y = center[0] - h/2
and only then
crop_img = img[y:y+h, x:x+w]
Just an additional comment for the Lenik’s answer (It is the first time I want to contribute in StackOverflow and don’t have enough reputation to comment the answer), you need to be sure x and y are integers.
Probably in this case x and y would always be integers as most of resolutions are even, but is a good practice to keep the values inside an int().
center = image.shape / 2
x = center[1] - w/2
y = center[0] - h/2
crop_img = img[int(y):int(y+h), int(x):int(x+w)]