Creating your own contour in opencv using python

Question

I have a set of boundary points of an object.

I want to draw it using opencv as contour.

I have no idea that how to convert my points to contour representation.

Answer 1

To create your own contour from a python list of points L

L=[[x1,y1],[x2,y2],[x3,y3],[x4,y4],[x5,y5],[x6,y6],[x7,y7],[x8,y8],[x9,y9],...[xn,yn]]

Create a numpy array ctr from L, reshape it and force its type

ctr = numpy.array(L).reshape((-1,1,2)).astype(numpy.int32)

ctr is our new countour, let's draw it on an existing image

cv2.drawContours(image,[ctr],0,(255,255,255),1)