OpenCV e Convex Hull

Rapaaaaaaaaaaaz, eu vou postar esse código aqui porque eu não achei em nenhum canto na internet uma pagina mostrando uma demo de convex hull

Podem usar a vontade!
Nosso código pra mostrar mostrar na tela a imagem da webcam e o Convex Hull, no caso eu to fazendo de objetos da cor amarela ou da cor verde

import cv2

import numpy as np

#epsilon = 0.1*cv2.arcLength(cnt,True)

# approx = cv2.approxPolyDP(cnt,epsilon,True)

#criando uma funcao

def nothing(x):

pass

cap = cv2.VideoCapture(0)

def make_1080p():

cap.set(3, 1920)

cap.set(4, 1080)

def make_720p():

cap.set(3, 1280)

cap.set(4, 720)

def make_480p():

cap.set(3, 640)

cap.set(4, 480)

def change_res(width, height):

cap.set(3, width)

cap.set(4, height)

make_480p()

loweryellow = np.array([13, 118, 100])

upperyellow = np.array([35, 255, 255])

lowergreen = np.array([33, 79, 51])

uppergreen = np.array([81, 255, 255])

while True:

_, frame = cap.read()

blurred_frame = cv2.GaussianBlur(frame, (5, 5), 0)

hsv = cv2.cvtColor(blurred_frame, cv2.COLOR_BGR2HSV)

#yellow

maskyellow = cv2.inRange(hsv, loweryellow, upperyellow)

cntyellow,hierarchyyellow = cv2.findContours(maskyellow, cv2.RETR_LIST, cv2.CHAIN_APPROX_NONE)

cntyellow = sorted(cntyellow, key=cv2.contourArea, reverse=True)

totalyellow = len(cntyellow)

#green

maskgreen = cv2.inRange(hsv, lowergreen, uppergreen)

cntgreen,hierarchygreen = cv2.findContours(maskgreen, cv2.RETR_LIST, cv2.CHAIN_APPROX_NONE)

cntgreen = sorted(cntgreen, key=cv2.contourArea, reverse=True)

totalgreen = len(cntgreen)

x, y, w, h, cor = -1, -1, -1, -1, "nenhuma"

areaYellow, areaGreen = 0, 0

if(totalyellow > 0):

hullyellow = cv2.convexHull(cntyellow[0])

cv2.drawContours(frame, [hullyellow], -1, (0, 232, 255), 4)

areaYellow = cv2.contourArea(hullyellow)

#agora isso aqui com certeza eh lixo, mas nao tem como saber a posicao sem isso

posxYellow,posyYellow,wYellow,hYellow = cv2.boundingRect(hullyellow)

if(totalgreen > 0):

hullgreen = cv2.convexHull(cntgreen[0])

cv2.drawContours(frame, [hullgreen], -1, (0, 255, 0), 4)

areaGreen = cv2.contourArea(hullgreen)

#agora isso aqui com certeza eh lixo, mas nao tem como saber a posicao sem isso

posxGreen,posyGreen,wGreen,hGreen = cv2.boundingRect(hullgreen)

cv2.imshow("frame", frame)

key = cv2.waitKey(1)

if key == 27:

break

if (areaGreen > areaYellow):

cor = "verde"

x = posxGreen

y = posyGreen

w = wGreen

h = hGreen

elif(areaGreen < areaYellow):

cor = "amarelo"

x = posxYellow

y = posyYellow

w = wYellow

h = hYellow

elif(areaGreen == 0 and areaYellow):

cor = "nenhuma"

print (cor)

cap.release()

cv2.destroyAllWindows()

Nosso código pra identificação de cor de caixa (se é verde ou amarela)

import cv2

import numpy as np

#criando uma funcao

def nothing(x):

pass

cap = cv2.VideoCapture(0)

def make_1080p():

cap.set(3, 1920)

cap.set(4, 1080)

def make_720p():

cap.set(3, 1280)

cap.set(4, 720)

def make_480p():

cap.set(3, 640)

cap.set(4, 480)

def change_res(width, height):

cap.set(3, width)

cap.set(4, height)

#make_480p()

def identificacor(img):

frame = img

blurred_frame = cv2.GaussianBlur(frame, (5, 5), 0)

hsv = cv2.cvtColor(blurred_frame, cv2.COLOR_BGR2HSV)

loweryellow = np.array([13, 118, 100])

upperyellow = np.array([35, 255, 255])

lowergreen = np.array([33, 79, 51])

uppergreen = np.array([81, 255, 255])

#yellow

maskyellow = cv2.inRange(hsv, loweryellow, upperyellow)

cntyellow,hierarchyyellow = cv2.findContours(maskyellow, cv2.RETR_LIST, cv2.CHAIN_APPROX_NONE)

cntyellow = sorted(cntyellow, key=cv2.contourArea, reverse=True)

totalyellow = len(cntyellow)

#green

maskgreen = cv2.inRange(hsv, lowergreen, uppergreen)

cntgreen,hierarchygreen = cv2.findContours(maskgreen, cv2.RETR_LIST, cv2.CHAIN_APPROX_NONE)

cntgreen = sorted(cntgreen, key=cv2.contourArea, reverse=True)

totalgreen = len(cntgreen)

x, y, w, h, cor = -1, -1, -1, -1, "nenhuma"

if(totalyellow > 0):

hullyellow = cv2.convexHull(cntyellow[0])

cv2.drawContours(frame, [hullyellow], -1, (0, 232, 255), 4)

areaYellow = cv2.contourArea(hullyellow)

#agora isso aqui com certeza eh lixo, mas nao tem como saber a posicao sem isso

posxYellow,posyYellow,wYellow,hYellow = cv2.boundingRect(hullyellow)

if(totalgreen > 0):

hullgreen = cv2.convexHull(cntgreen[0])

cv2.drawContours(frame, [hullgreen], -1, (0, 255, 0), 4)

areaGreen = cv2.contourArea(hullgreen)

#agora isso aqui com certeza eh lixo, mas nao tem como saber a posicao sem isso

posxGreen,posyGreen,wGreen,hGreen = cv2.boundingRect(hullgreen)

if (areaGreen > areaYellow):

cor = "verde"

x = posxGreen

y = posyGreen

w = wGreen

h = hGreen

elif(areaGreen < areaYellow):

cor = "amarelo"

x = posxYellow

y = posyYellow

w = wYellow

h = hYellow

elif(areaGreen == 0 and areaYellow):

cor = "nenhuma"

w = w/2

h = h / 2

x = x + w

y = y + h

return cor, x, y, w, h

def identificacorimagem (imagem):

img = cv2.imread(imagem, cv2.IMREAD_COLOR)

cor, x, y, w, h = identificacor(img)

return cor, x, w, w, h

def identificacorimgcamera ():

make_480p()

_, frame = cap.read()

cor, x, y, w, h = identificacor(frame)

return cor, x, w, w, h

testecor, testex, testey, testew, testeh = identificacorimgcamera ()

print(testecor)

if testecor == "amarelo":

testecor, testex, testey, testew, testeh = identificacorimagem ('quad8.jpg')

print(testecor)

Referencias:
https://www.youtube.com/watch?v=nspSQSU_zvk&t=21s
https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_imgproc/py_contours/py_contour_features/py_contour_features.html
https://www.pyimagesearch.com/2014/08/04/opencv-python-color-detection/
https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_imgproc/py_colorspaces/py_colorspaces.html