anandvd's profile - activity

I am trying to see all the black doublets in a straight line. I have tried using toPolar() but it gives me a distorted image like this. Since this approach didn't work well, I am now trying to extract each doublet (which will be contained in a "pizza slice" like shape, centered at the center of the image) and place them next to each other.

Thanks for the comment! What confuses me, is that since all points on the image are not connected, how can I make a contour surrounding just the image? (similar to what the hull gives, but a contour)

I made the exterior contour using the following:

def contoursConvexHull(contours):
    pts = []
    for i in range(0, len(contours)):
        for j in range(0, len(contours[i])):
            pts.append(contours[i][j])

    pts = np.array(pts)
    result = cv2.convexHull(pts)
    return result

image = cv2.imread(args["image"])
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
blurred = cv2.GaussianBlur(gray, (5,5), 0)
thresh = cv2.threshold(blurred, 60, 255, cv2.THRESH_BINARY)[1]
imageCanny = cv2.Canny(blurred, 100, 200, 3)

img, contours, hierarchy = cv2.findContours(imageCanny, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

ConvexHullPoints = contoursConvexHull(contours)
cv2.polylines(image, [ConvexHullPoints], True, (0,255,255), 2)

and accessed the center of the contour using the following:

c = max(contours, key = cv2.contourArea)
M = cv2.moments(c)
if M["m00"] != 0:
    cX = int(M["m10"] / M["m00"])
    cY = int(M["m01"] / M["m00"])
    print (cX,cY)
else:
    cX, cY = 0,0
    print (cX,cY)

My questions: 1. Since my image is not continuous, am I right in using convexHull and polylines() to draw the contour? 2. If I am right in using the above functions, how can I access ALL the points on the convexHull contour? Currently, if I use

cpts = []
cpts.append(ConvexHullPoints)
cpts = np.array(cpts)
print (cpts)

to see the points, I only get an array of 35 points.

Is there a way in OpenCV to slice a 3D image into its constituent 2D slices. For example, cutting a 3D cylinder along planes parallel to its base

OpenCV3, Python3.5.1

It works! Thanks! But in the documentation it mentions the destination as a parameter as well

I tried making it float, but still getting the same error

I am trying to convert concentric circles into straight lines using linear polar:

circleArr = np.ndarray((512,512), dtype = np.float32)
for i in range(10,600,10):
    cv2.circle(circleArr, (256,256), i-10, np.random.randint(60,500), thickness = 4)

lp = np.ndarray((512,512), dtype=np.float32)
img1 = cv2.linearPolar(circleArr, lp, (256,256), 100, cv2.INTER_LINEAR+cv2.WARP_FILL_OUTLIERS)

I get the following error referring to the last line:

TypeError: a float is required

I am confused because both the input and output array in the linearPolar() function are float type

Opencv3 and python 3.5.1

I have a 3D .mrc file of cilia microtubules which was generated using electron microscopy. It is a cylindrical image, and I am trying to "cut it open" along the central axis to flatten it (still a 3D image). I am attaching a sample image of how it might look. Please help!