hsv_finder.py

#!/usr/bin/env python
import cv2
import sys
import numpy as np

def nothing(x):
    pass
cap= cv2.VideoCapture(0)
# Load in image
# image = cv2.imread('1.jpg')
ret, image = cap.read()

# Create a window
cv2.namedWindow('image',cv2.WINDOW_NORMAL)

# create trackbars for color change
cv2.createTrackbar('HMin','image',0,179,nothing) # Hue is from 0-179 for Opencv
cv2.createTrackbar('SMin','image',0,255,nothing)
cv2.createTrackbar('VMin','image',0,255,nothing)
cv2.createTrackbar('HMax','image',0,179,nothing)
cv2.createTrackbar('SMax','image',0,255,nothing)
cv2.createTrackbar('VMax','image',0,255,nothing)

# Set default value for MAX HSV trackbars.
cv2.setTrackbarPos('HMax', 'image', 179)
cv2.setTrackbarPos('SMax', 'image', 255)
cv2.setTrackbarPos('VMax', 'image', 255)

# Initialize to check if HSV min/max value changes
hMin = sMin = vMin = hMax = sMax = vMax = 0
phMin = psMin = pvMin = phMax = psMax = pvMax = 0

output = image
wait_time = 1


while True:
    ret, image = cap.read()
    while True:
        # get current positions of all trackbars
        hMin = cv2.getTrackbarPos('HMin','image')
        sMin = cv2.getTrackbarPos('SMin','image')
        vMin = cv2.getTrackbarPos('VMin','image')

        hMax = cv2.getTrackbarPos('HMax','image')
        sMax = cv2.getTrackbarPos('SMax','image')
        vMax = cv2.getTrackbarPos('VMax','image')

        # Set minimum and max HSV values to display
        lower = np.array([hMin, sMin, vMin])
        upper = np.array([hMax, sMax, vMax])

        # Create HSV Image and threshold into a range.
        hsv = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)
        mask = cv2.inRange(hsv, lower, upper)
        output = cv2.bitwise_and(image,image, mask= mask)

        # Print if there is a change in HSV value
        if( (phMin != hMin) | (psMin != sMin) | (pvMin != vMin) | (phMax != hMax) | (psMax != sMax) | (pvMax != vMax) ):
            print("(hMin = %d , sMin = %d, vMin = %d), (hMax = %d , sMax = %d, vMax = %d)" % (hMin , sMin , vMin, hMax, sMax , vMax))
            phMin = hMin
            psMin = sMin
            pvMin = vMin
            phMax = hMax
            psMax = sMax
            pvMax = vMax

        # Display output image
        cv2.imshow('image',output)

        # Wait longer to prevent freeze for videos.
        if cv2.waitKey(wait_time) & 0xFF == ord('q'):
            break

cv2.destroyAllWindows()