I have an ultrasound image and the coordinates (array of x and y points) of the tumor of each image. How can I make a contour around the tumor with those known coordinates using cv.drawContours()? I wish to delete all the information around the tumor and stay only with the tumor image/information. I am gettin…
Tag: contour
OpenCV Drawing Contour Error Assertion Failed
So I am trying to follow guide on how to scan a document in https://www.pyimagesearch.com/2014/09/01/build-kick-ass-mobile-document-scanner-just-5-minutes/ exactly on the step 2 process where i am supposed to find the contour and draw it to the image, i got an “Assertion Failed” error on drawConto…
Create random shape/contour using matplotlib
I am trying to generate an image of a random contour using python but I couldn’t find an easy way to do it. Here is an example sort of what I want: Initially I tought of doing it using matplotlib and gaussian functions, but I could not even get close to the image I showed. Is there a simple way
How to detect and draw contours using OpenCV in Python?
I wrote the following code to detect and draw contours: And here is the error I received: Traceback (most recent call last): File “C:/Users/R.K.singh/Desktop/Image processing/intro-to-contours.py”, line 10, in contours,hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE); Val…
Python showing an OpenCV Assertion error for finding contours
I was trying to draw contours in an image using Python OpenCV. My code is the following: I am getting an error while compiling this code. The error is the following: How can I avoid this error? Answer The problem should be that cv2.drawContours (and in general all opencv “drawing” functions in pyt…
Problems in traversing contours in python using OpenCV library
I am designing an algorithm in which I have to traverse through every contour in an image and apply a condition on it. I am using OpenCV library to do this. And the code is as follows: The error is: Answer I have never used h_next but whenever I’ve iterated over contours has worked. It appears that you&…
Access pixel values within a contour boundary using OpenCV in Python
I’m using OpenCV 3.0.0 on Python 2.7.9. I’m trying to track an object in a video with a still background, and estimate some of its properties. Since there can be multiple moving objects in an image, I want to be able to differentiate between them and track them individually throughout the remainin…
OpenCV Python: cv2.findContours – ValueError: too many values to unpack
I’m writing an opencv program and I found a script on another stackoverflow question: Computer Vision: Masking a human hand When I run the scripted answer, I get the following error: The code: Any help is appreciated! Answer I got the answer from the OpenCV Stack Exchange site. Answer THE ANSWER: I bet …
Creating your own contour in opencv using python
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. To the same contour representation which is obtained by following call Any ideas? Thanks Answer By looking at the format of the contours I would thin…