Hello I've started the following live chroma key in python for a greenscreen:
import numpy as np
import cv2
rows = 800
cols = 600
cap = cv2.VideoCapture(1) #use external cam
ret = cap.set(3,rows)
ret = cap.set(4,cols)
img_back = cv2.imread('background.jpg')
background = img_back[0:cols, 0:rows ]
thresh = 230
blur = 3
final = ""
display=1
kernel = np.ones((5,5),np.uint8)
# create window
cv2.namedWindow("chroma", cv2.WND_PROP_FULLSCREEN)
cv2.setWindowProperty("chroma", cv2.WND_PROP_FULLSCREEN, cv2.cv.CV_WINDOW_FULLSCREEN)
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
frame = cv2.flip(frame,1,frame)
lab_image = cv2.cvtColor(frame, cv2.COLOR_BGR2LAB)
l_channel,chan_a,chan_b = cv2.split(lab_image)
b_channel = cv2.bitwise_not(chan_b)
a_channel = cv2.add(chan_a,b_channel)
a_channel = cv2.bitwise_not(a_channel)
a_channel_inv = cv2.bitwise_not(a_channel)
# create mask
im_bw = cv2.threshold(a_channel_inv, thresh, 255, cv2.THRESH_BINARY)[1]
im_bw = cv2.GaussianBlur(im_bw,(blur,blur),0)
im_bw = cv2.morphologyEx(im_bw, cv2.MORPH_OPEN, kernel)
ret ,im_bw = cv2.threshold(im_bw,thresh,255,cv2.THRESH_BINARY)
im_bw_inv = cv2.bitwise_not(im_bw)
im_bw_inv = cv2.GaussianBlur(im_bw_inv,(1,1),0)
im_bw_inv = cv2.morphologyEx(im_bw_inv, cv2.MORPH_CLOSE, kernel)
roi = cv2.bitwise_and(background,background,mask = im_bw_inv)
im = cv2.bitwise_and(frame,frame,mask = im_bw)
# add mask
dst = cv2.add(roi,im)
# Display the resulting frame
k = cv2.waitKey(33)
if k == 27: #ESC
break
if k == ord("+"):
thresh+=1
if k == ord("-"):
thresh-=1
if k == ord("."):
blur*=3
if k == ord(","):
if blur > 1:
blur/=3
if k == ord("1"):
display = 1
if k == ord("2"):
display = 2
if k == ord("3"):
display = 3
if k == ord("4"):
display = 4
if k == ord("5"):
display = 5
if k == ord("6"):
display = 6
if k == ord("7"):
display = 7
if k == ord("8"):
display = 8
if (display == 1):
final = dst
if (display == 2):
final = im
if (display == 3):
final = roi
if (display == 4):
final = im_bw
if (display == 5):
final = im_bw_inv
if (display == 6):
final = chan_a
if (display == 7):
final = chan_b
if (display == 8):
final = l_channel
#display image
cv2.putText(dst,"Thresh (+/-): " + str(thresh), (20,40), cv2.FONT_HERSHEY_SIMPLEX,0.5, 0)
cv2.putText(dst,"Blur (./,): " + str(blur), (20,60), cv2.FONT_HERSHEY_SIMPLEX,0.5, 0)
cv2.imshow('chroma', final)
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
It's working but since I'm a new to opencv I think it can be optimized and be better (especially in the small areas).
You can use the number keys to switch between the different masks/images and +,.- to change some settings (blur and threshold)
Any thoughts about the script? Looking forward for some optimization!
Best Peter
