CODEWITHSUNDEEP
pythonopencvimage-processinghough-transform
Yavuzhan Erdem
Yavuzhan Erdem

Reputation: 23

Hough Circle Transform on Video

import cv2
import numpy as np

cap = cv2.VideoCapture(0)

while(1):

# Take each frame
_, frame = cap.read() # frame olarak goruntuyu aldık

# BGR ' yi HSV ye çevirdik
hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)

# HSV nin içindeki renk aralıgını belirledik
lower_yellow = np.array([20,0,0])
upper_yellow = np.array([40,255,255])

# Yukarıda belırledıgımız eşik değerlerini gray goruntunun içinde eşleştirdik.
mask = cv2.inRange(hsv, lower_yellow, upper_yellow)

# bitwise and operatörü ile de ana goruntude yukarıda buldugumuz mask'i aldık.
res = cv2.bitwise_and(frame,frame, mask= mask)
img = cv2.medianBlur(res, 5)

cimg = cv2.cvtColor(img, cv2.COLOR_HSV2BGR)
cimg = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
circles = cv2.HoughCircles(img, cv2.HOUGH_GRADIENT, 5, 20,
                           param1=50, param2=30, minRadius=0, maxRadius=10)

circles = np.uint16(np.around(circles))
for i in circles[0, :]:
    # draw the outer circle
    cv2.circle(cimg, (i[0], i[1]), i[2], (0, 255, 0), 2)
    # draw the center of the circle
    cv2.circle(cimg, (i[0], i[1]), 2, (0, 0, 255), 3)

cv2.imshow('detected circles', cimg)
#ayarladıgımız 3 görüntüyü gösterdik

cv2.imshow('res',res)
k = cv2.waitKey(5) & 0xFF
if k == 27:
    break

cv2.destroyAllWindows()

When I run , There is a error called : 

cv2.error: /io/opencv/modules/imgproc/src/hough.cpp:1494: error: (-215) !_image.empty() && _image.type() == (((0) & ((1 << 3) - 1)) + (((1)-1) << 3)) && (_image.isMat() || _image.isUMat()) in function HoughCircles

I want to find circle on video .

Upvotes: 0

Views: 2838

Answers (2)

Devansh Soni
Devansh Soni

Reputation: 771

Yeah! Hough Circle Transform is for Grayscale images only. So you have to give "cimg" (from your code) as input to HoughCircles.

Also, you don't have to write this line:

cimg = cv2.cvtColor(img, cv2.COLOR_HSV2BGR)

Upvotes: 1

Piglet
Piglet

Reputation: 28950

HoughTransform is only supported on greyscale images

cv2.HoughCircles(image, method, dp, minDist[, circles[, param1[, param2[, minRadius[, maxRadius]]]]]) → circles

Parameters: image – 8-bit, single-channel, grayscale input image.

Either pick one channel or convert your image to single channel.

Upvotes: 0

Related Questions