MingCheng's profile - activity

Basically is just the problem of when there is no measurement input, the result of the kalman filter prediction will not

opencv kalman filter(python) problem when no detection Hi, when I am trying to use the opencv Kalman Filter to track a

opencv kalman filter(python) problem when no detection Hi, when I am trying to use the opencv Kalman Filter to track a

opencv kalman filter(python) problem when no detection Hi, when I am trying to use the opencv Kalman Filter to track a

Kalman filter predict both velocity and position Hi, I trying to follow the example, in this site, https://blog.csdn.n

Thank you very much for the advice.

Hi may I know that what is the meaning of the line "key=cv2.contourArea" in the max() function. Thank you for reading th

Thank you, I was too careless.

Hi, May I ask that why I get a syntax error for the line output = cv.inRange(hsv, lower_blue, upper_blue). The code is shown below:

import numpy as np
import cv2  as cv   
con=[]
image = cv.imread('2.jpg')
hsv = cv.cvtColor(image, cv.COLOR_RGB2HSV)

lower_blue = np.array([1,80,53])
upper_blue = np.array([53,205,255]
output = cv.inRange(hsv, lower_blue, upper_blue)
con = cv.findContours(output.copy(),cv.RETR_LIST,cv.CHAIN_APPROX_NONE)
print(con)
#print(hier)
cv.imshow('img', image)
cv.waitKey(0)

Thank you for the help

My apologies, here is the relevant portion. bluecnts = cv2.findContours(mask.copy(),cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_S

syntax error for cv2.inRange Hi, May I ask that why I get a syntax error for the line output = cv.inRange(hsv, lower_b

Hi, I am a beginner to openCV, and wanted trying to implement a slide bar and draw a contours around the masked image. My code is shown as below:

May I also ask that: 1. Sometimes, there is a square bracket with values e.g. [-1], [0] behind the function cv.findContours(mask,cv.RETR_TREE,cv.CHAIN_APPROX_NONE), what are they these square brackets with values is used for? 2. I found contours, hierarchy = cv.findContours(image, mode, method[, contours[, hierarchy[, offset]]]) in the openCV official website. I understand that we can pass in image,mode,and method to the function, but what is the meanning of [, contours[, hierarchy[, offset]]]

Thank you for reading.

import numpy as np
import cv2 as cv
def empty(x):
    pass

#lower_blue = np.array([1,80,53])
#upper_blue = np.array([200,205,255])

img = np.zeros((512,512,3),np.uint8)
cv.rectangle(img,(100,100),(277,307),(155,0,0),-1,)
#cv.circle(img,(450,450),50,(155,0,0),-1)
#img = cv.imread("orange.jpg")
hsv = cv.cvtColor(img, cv.COLOR_BGR2HSV)
cv.namedWindow("my_mask")
cv.createTrackbar("LH","my_mask",0,255,empty)
cv.createTrackbar("LS","my_mask",0,255,empty)
cv.createTrackbar("LV","my_mask",0,255,empty)
cv.createTrackbar("UH","my_mask",255,255,empty)
cv.createTrackbar("US","my_mask",255,255,empty)
cv.createTrackbar("UV","my_mask",255,255,empty)
LH = cv.getTrackbarPos("LH", "my_mask")
LS = cv.getTrackbarPos("LS", "my_mask")
LV = cv.getTrackbarPos("LV", "my_mask")
UH = cv.getTrackbarPos("UH", "my_mask")
US = cv.getTrackbarPos("US", "my_mask")
UV = cv.getTrackbarPos("UV", "my_mask")
#lower = np.array([LH,LS,LV])
#upper = np.array([UH,US,UV])
lower = np.array([0,100,100])
upper = np.array([255,255,255])
mask = cv.inRange (hsv, lower, upper)
countours = cv.findContours(mask,cv.RETR_TREE,cv.CHAIN_APPROX_NONE) #it returns a turples, every element of turples starts with "array", it is verified by using len()
#Barea = cv.contourArea
#print(len(countours))
#print(countours[2])
#cv.drawContours(img,[countours],-1,(0,255,255),5)
cv.imshow("original",img)
cv.imshow("my_mask",mask)

cv.waitKey(0)

cv.destroyAllWindows()

Basic openCV contour questions Hi, May I ask that what is the meaning of this line of code: "key=cv2.contour

Basic openCV contour questions Hi, 1. May I ask that what is the meaning of this line of code: "key=cv2.cont

slide bar not working and unable to draw contours Hi, I am a beginner to openCV, and wanted trying to implement a slid

Installed Opencv 4.1.2 pre on Ubuntu 16.04 but version shown is 2.4.9 Hi, Recently I installed opencv 4.1.2 pre on Ub

Installed Opencv 4.1.2 pre on Ubuntu 16.04 but version shown is 2.4.9 Hi, Recently I installed opencv 4.1.2 pre on Ub