Monday, July 8, 2013

Using findContours from OpenCV python module.

Today I will show something nice about OpenCV Analysis and Shape Descriptors.

This function finds contours in a binary image.

All detected contours is stored as a vector of points for each contour.

import cv2
im = cv2.imread('your_image.jpg')
img_gray = cv2.cvtColor(im,cv2.COLOR_RGB2GRAY)
ret,thresh = cv2.threshold(img_gray,127,255,0)
contours, hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)

If you got this error:

findContours error 'support only 8uC1 images'

then the main reason it's findContours requires a monochrome image.

Let's see the result of the python script.

The contour it's draw with 250,250,250 color.