Detect concentric circles (python)

I want to detect circles in image as below:

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So, I tried with cv2.findContours and cv2.Houghcirclesin python, but there were some problems.Both methods were applied after image processing (Canny, threshold, etc.)

First, if I use cv2.findCountours, it cannot detect outer circles since they were overlapped and detect as a single contour.Here's my python code.

contours, hier = cv2.findContours(input, cv2.RETR_CCOMP, cv2.CHAIN_APPROX_SIMPLE)for contour in contours:    c= (random.randint(0,255),random.randint(0,255),random.randint(0,255))    if area>10000 and area<100000:       # Filtering the target size        (x, y), radius = cv2.minEnclosingCircle(contour)        center= (int(x), int(y))        radius= int(radius)        cv2.circle(color, center, radius, c,5)

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Second, if I use cv2.Houghcircles (Split the radius range to detect concentric circles), the results were better, but still the results were poor.

for maxR in range(100,200,10): # minimum 100 to maximum 200 by step 10    circles = cv2.HoughCircles(input, cv2.HOUGH_GRADIENT, 1, 100, param1=100,param2=22,minRadius=minR,maxRadius=maxR)    minR+=10    # Check to see if there is any detection    if circles is not None:        # If there are some detections, convert radius and x,y(center) coordinates to integer        circles = np.round(circles[0, :]).astype("int")        for (x, y, r) in circles:            c= (random.randint(0,255),random.randint(0,255),random.randint(0,255))            cv2.circle(view, (x, y), r, c, 3)                                      # draw circumference            cv2.rectangle(view, (x - 2, y - 2), (x + 2, y + 2), c, 5)              # draw center

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Is there any better methods to detect concentric circles in image and measure center coordinates and radius of them?

I compared the encloed area and minimum enclosing circle area.And I got circular contours.

contours, hier = cv2.findContours(aaa, cv2.RETR_CCOMP, cv2.CHAIN_APPROX_NONE)for contour in contours:    c= (random.randint(0,255),random.randint(0,255),random.randint(0,255))    area = cv2.contourArea(contour)    (cx, cy), radius = cv2.minEnclosingCircle(contour)    err=abs((area-np.pi*radius*radius)/(np.pi*radius*radius))    if err< 0.1:        cv2.drawContours(aaa, [contour], -1, (255,255,255) , thickness=cv2.FILLED)        cv2.drawContours(color, [contour], -1, c , 5)

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Then, I filled the area with white color.Image may be NSFW.
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Now, the problem is very simple.All I need to do is separate the overlapping circles into their own circles. (I can find many references)

Thanks you all!