Trying to modify a code to capture an image every 15 minutes or so (time lapse) - list

Question

Below code was taken from an existing post by Kieleth which I use as a subset of my larger codebase. I'm trying to leverage it to capture a list of frames taken once every thousand+ real time frames and later play in a time-lapse fashion. I've captured the frames but can't seem to view them when calling a simple function. I've seen in other posts that for loops are not recommended for this type of event but haven't figured out how to properly display. Any advise on this one would be appreciated?
from tkinter import ttk
import time
import cv2
from PIL import Image,ImageTk
#import threading
root = Tk()
def video_button1():# this flips between start and stop when video button pressed.
if root.video_btn1.cget('text') == "Stop Video":
root.video_btn1.configure(text = "Start Video")
root.cap.release()
elif root.video_btn1.cget('text') == "Start Video":
root.video_btn1.configure(text = "Stop Video")
root.cap = cv2.VideoCapture(0)
show_frame()
def show_frame():
# if video_btn1.cget('text') == "Stop Video":
global time_lapse_counter
ret, frame = root.cap.read()
if ret:
frame = cv2.flip(frame, 1) #flip image
cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
img = Image.fromarray(cv2image)
imgtk = ImageTk.PhotoImage(image=img) #converts img into tkinter readable format
root.video_label.imgtk = imgtk
if time_lapse_counter >= 20: # for Every 20 frames, capture one into time_lapse_list
time_lapse_list.append(imgtk)
time_lapse_counter = 0
root.video_label.configure(image=imgtk)
if len(time_lapse_list) == 5: # keep only 4 frames in the list *** debug purposes.
time_lapse_list.pop(0)
time_lapse_counter += 1
video_loop = root.after(40, show_frame)
else:
root.video_btn1.configure(text = "Start Video")
def time_lapse_play():
root.cap.release() #stop capturing video.
for image in time_lapse_list:
print (image, " ", len(time_lapse_list)," ",time_lapse_list) #
#*** I see the print of the pyimagexxx but nothing appears on the video***#
imgtk = image
root.video_label.imgtk = imgtk
root.video_label.configure(image=imgtk)
cv2.waitKey(500)
# video_loop = root.after(500, time_lapse_play)
def setup_widgets(): #simple label and 2 button widget setup
#Setup Top Right Window with pictures
f_width, f_height = 810, 475
root.rightframe= Frame(root, border=0, width=f_width, height = f_height)
root.rightframe.grid(row=0, column=0, padx=10, pady=0)
# Show video in Right Frame
root.cap = cv2.VideoCapture(0)
root.cap.set(cv2.CAP_PROP_FRAME_WIDTH, f_width)
root.cap.set(cv2.CAP_PROP_FRAME_HEIGHT, f_height)
root.video_label = Label(root.rightframe)
root.video_label.grid(row=0, column = 0)
root.video_btn1 = Button(root.rightframe, fg='maroon', bg="yellow", text = "Stop Video", font=("Arial",10),height=0, width = 10, command=video_button1)
root.video_btn1.grid(row=0, column = 1)
root.video_btn2 = Button(root.rightframe, fg='maroon', bg="yellow", text="Time Lapse", font=("Arial",10),height=0, width = 10, command=time_lapse_play)
root.video_btn2.grid(row=1, column = 1)
# Main Code
screen_width = root.winfo_screenwidth()
screen_height = root.winfo_screenheight()
screen_resolution = str(screen_width)+'x'+str(screen_height)
root.geometry(screen_resolution)
time_lapse_counter = 0
time_lapse_list=[]
setup_widgets()
show_frame()
root.mainloop()```

Answer 1

I've finally figure this one out. Seems that the for loop effectively doesn't work when using callback. I've modified the code to remove the for loop. I'm sure it could use some improvements but it works. I'm not sure how to reset the image count within the list as pop/append grows the list image number over time and I wonder about an overflow error. i.e after a few minutes, the list will contain [pyimage100 - pyimage200], after a few hours, [pyimage1000000 - pyimage1000100].
from tkinter import *
import cv2
from PIL import Image,ImageTk
from matplotlib.backends.backend_tkagg import (FigureCanvasTkAgg)
import matplotlib.pyplot as plt
root = Tk()
def video_button1():# this flips between start and stop when video button pressed.
if root.video_btn1.cget('text') == "Stop Video":
root.video_btn1.configure(text = "Start Video")
root.cap.release()
elif root.video_btn1.cget('text') == "Start Video":
root.video_btn1.configure(text = "Stop Video")
root.cap = cv2.VideoCapture(0)
root.cap.set(cv2.CAP_PROP_FRAME_WIDTH, 400)
root.cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 400)
show_frame()
def show_frame():
# if video_btn1.cget('text') == "Stop Video":
global time_lapse_counter
ret, frame = root.cap.read()
if ret:
frame = cv2.flip(frame, 1) #flip image
cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
img = Image.fromarray(cv2image)
imgtk = ImageTk.PhotoImage(image=img) #converts img into tkinter readable format
root.video_label.imgtk = imgtk
root.video_label.configure(image=imgtk)
if time_lapse_counter >= 20: # for Every 20 frames, capture one into time_lapse_list
time_lapse_list.append(imgtk)
time_lapse_counter = 0
if len(time_lapse_list) == 100: # keep 99 frames in the list
time_lapse_list.pop(0)
time_lapse_counter += 1
video_loop = root.after(40, show_frame)
else:
root.video_btn1.configure(text = "Start Video")
def time_lapse_play():
root.cap.release() #stop capturing video.
global frame_counter
if frame_counter <= len(time_lapse_list)-1:
imgtk = time_lapse_list[frame_counter] # get image from list
root.video_label.configure(image=imgtk) # update label with image from list
frame_counter += 1
video_loop = root.after(250, time_lapse_play) #wait 250ms until next frame
else:
frame_counter = 0 #reset frame_counter
def setup_widgets(): #simple label and 2 button widget setup
#Setup Top Right Window with pictures
f_width, f_height = 1200, 500
root.rightframe= Frame(root, border=0, width=f_width, height = f_height)
root.rightframe.grid(row=0, column=0, padx=10, pady=0)
# Show video in Right Frame
root.cap = cv2.VideoCapture(0)
root.cap.set(cv2.CAP_PROP_FRAME_WIDTH, 400)
root.cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 400)
root.video_label = Label(root.rightframe)
root.video_label.grid(row=0, column = 0)
root.video_btn1 = Button(root.rightframe, fg='maroon', bg="yellow", text =
"Stop Video", font=("Arial",10),height=0, width = 10, command=video_button1)
root.video_btn1.grid(row=0, column = 1)
root.video_btn2 = Button(root.rightframe, fg='maroon', bg="yellow", text="Time Lapse", font=("Arial",10),height=0, width = 10, command=time_lapse_play)
root.video_btn2.grid(row=1, column = 1)
fig = plt.figure(1)
canvas = FigureCanvasTkAgg(fig, root.rightframe)
canvas.get_tk_widget().place(x=700,y=0)
canvas.get_tk_widget().config(border=2, bg="yellow", width=400, height=400)
# Main Code
screen_width = root.winfo_screenwidth()
screen_height = root.winfo_screenheight()
screen_resolution = str(screen_width)+'x'+str(screen_height)
root.geometry(screen_resolution)
time_lapse_counter = 0
frame_counter = 0
time_lapse_list=[]
setup_widgets()
show_frame()
root.mainloop()
`