OpenCV - Circle Detection Too Sensitive Even with Blur - opencv

Question

Hi, just posting this on behalf of my 10yo son. He's working on a Python/OpenCV/GUI application and having some issues. Hoping someone might be able to point him in the right direction. Information as per below (maybe he needs to take a different approach?)
At the moment in my project I am having a problem with no errors. The only problem is the code isn't doing exactly what I want it to be. I can not tell if the blur is too strong, the blur is making the circle detection more sensitive or something else. My code is below.
I am trying to make the circle detection less sensitive by using a blur, however I can not tell what it's doing because there is no error.
What I want it to do is:
blur the image
ensure the circle detection is not to sensitive (not too many circles)
show the image unblurred and on the unblurred image show the circles from the blurred image
For an example, I should be able to detect moon craters.
import tkinter as tk
from tkinter import filedialog
from PIL import ImageTk, Image
import numpy as np
import cv2
root = tk.Tk()
root.title("Circle detecter")
root.geometry("1100x600")
root.iconbitmap('C:/Users/brett/')
def open():
global my_image
filename = filedialog.askopenfilename(initialdir="images", title="Select A File", filetypes=(("jpg files", "*.jpg"),("all files", "*.*")))
my_label.config(text=filename)
my_image = Image.open(filename)
tkimg = ImageTk.PhotoImage(my_image)
my_image_label.config(image=tkimg)
my_image_label.image = tkimg # save a reference of the image
def find_circles():
# convert PIL image to OpenCV image
circles_image = np.array(my_image.convert('RGB'))
gray_img = cv2.cvtColor(circles_image, cv2.COLOR_BGR2GRAY)
img = cv2.medianBlur(gray_img, 5)
circles = cv2.HoughCircles(img, cv2.HOUGH_GRADIENT, 1, 20,
param1=20, param2=60, minRadius=20, maxRadius=200)
if circles is not None:
circles = np.uint16(np.around(circles))
for i in circles[0]:
# draw the outer circle
cv2.circle(circles_image, (i[0],i[1]), i[2], (0,255,0), 2)
# draw the center of the circle
cv2.circle(circles_image, (i[0],i[1]), 2, (0,0,255), 3)
# convert OpenCV image back to PIL image
image = Image.fromarray(circles_image)
# update shown image
my_image_label.image.paste(image)
tk.Button(root, text="Load Image", command=open).pack()
tk.Button(root, text="Find circles", command=find_circles).pack()
# for the filename of selected image
my_label = tk.Label(root)
my_label.pack()
# for showing the selected image
my_image_label = tk.Label(root)
my_image_label.pack()
root.mainloop()