How to find the mouse hover positions (preferably timestamps) on a video? - python-2.7

Question

I am trying to save the mouse hover positions in a given video. I need to load the video on a 'Load Video' button press. When the mouse is outside the canvas no (x,y) should be saved. I also want the video to streamed at much lower rate (say, 4 times slower). Presently, I have the following code:`
import Tkinter as tk
from Tkinter import *
import PIL.Image,PIL.ImageTk
import time
import cv2
class App:
def __init__(self, window, window_title, video_source=0):
self.window = window
self.window.title(window_title)
self.video_source = video_source
self.video_loaded=False
# open video source (by default this will try to open the computer webcam)
self.vid = MyVideoCapture(self.video_source)
# Create a canvas that can fit the above video source size
self.canvas = tk.Canvas(window, width = self.vid.width, height =
self.vid.height)
self.canvas.pack()
self.canvas.bind('<Motion>',self.canvas.motion)
#self.canvas.bind("<Enter>", self.on_enter)
#self.canvas.bind("<Leave>", self.on_leave)
# Button that lets the user take a snapshot
self.btn_snapshot=tk.Button(window, text="Snapshot", width=50,
command=self.snapshot)
self.btn_snapshot.pack(anchor=tk.CENTER, expand=True)
self.btn_collapse=tk.Button(window, text="Collapse", width=50,
command=self.collapse)
self.btn_collapse.pack(anchor=tk.CENTER, expand=True)
self.btn_load_video=tk.Button(window, text="Load Video", width=50,
command=self.load_video)
self.btn_load_video.pack(anchor=tk.CENTER, expand=True)
#if self.video_loaded==True:
# After it is called once, the update method will be automatically
called every delay milliseconds
self.delay = 15
self.update()
self.window.mainloop()
def load_video(self):
# open video source (by default this will try to open the computer
webcam)
self.vid = MyVideoCapture(self.video_source)
self.video_loaded=True
def snapshot(self):
# Get a frame from the video source
ret, frame = self.vid.get_frame()
if ret:
cv2.imwrite("frame-" + time.strftime("%d-%m-%Y-%H-%M-%S") + ".jpg",
cv2.cvtColor(frame, cv2.COLOR_RGB2BGR))
def collapse(self):
self.window.quit()
def motion(self):
self.x=self.canvas.winfo_pointerx
self.y=self.canvas.winfo_pointery
print('{},{}'.format(self.x, self.y))
#self.canvas.itemconfigure(text='({x},{y})'.format(x = self.x,
y=self.y))
#print('{},{}'.format(self.x, self.y))
#def motion(self):
# x, y = self.x, self.y
# print('{}, {}'.format(x, y))
#def on_enter(self, event):
# self.l2.configure(text="Hello world")
#def on_leave(self, enter):
# self.l2.configure(text="")
def update(self):
# Get a frame from the video source
ret, frame = self.vid.get_frame()
if ret:
self.photo = PIL.ImageTk.PhotoImage(image =
PIL.Image.fromarray(frame))
self.canvas.create_image(0, 0, image = self.photo, anchor = tk.NW)
self.window.after(self.delay, self.update)
class MyVideoCapture:
def __init__(self, video_source=0):
# Open the video source
video_source='./videofilename.wmv'
self.vid = cv2.VideoCapture(video_source)
if not self.vid.isOpened():
raise ValueError("Unable to open video source", video_source)
# Get video source width and height
self.width = self.vid.get(cv2.CAP_PROP_FRAME_WIDTH)
self.height = self.vid.get(cv2.CAP_PROP_FRAME_HEIGHT)
def get_frame(self):
if self.vid.isOpened():
ret, frame = self.vid.read()
if ret:
# Return a boolean success flag and the current frame converted
to BGR
return (ret, cv2.cvtColor(frame, cv2.COLOR_BGR2RGB))
else:
return (ret, None)
else:
return (ret, None)
# Release the video source when the object is destroyed
def __del__(self):
if self.vid.isOpened():
self.vid.release()
# Create a window and pass it to the Application object
root = tk.Tk()
App(root, "Tkinter and OpenCV")
When I run this, I get the following error:
Exception in Tkinter callback
Traceback (most recent call last):
File "/home/anaconda2/envs/my_env/lib/python2.7/lib-tk/Tkinter.py", line
1541, in __call__
return self.func(*args)
TypeError: motion() takes exactly 1 argument (2 given)
I want the function motion() to return the mouse hover positions. Appreciate help. Thanks in advance.
Here is the link from which the I got the main code.

Answer 1

The bind() function sends an event object to the callback function, but the motion() function only accepts self. Try:
def motion(self, event):
self.x=event.x
self.y=event.y
Binding the function for saving mouse positions can be done as in teh example below.
from tkinter import *
root = Tk()
root.geometry('300x200+800+50')
c = Canvas(root, bg='tan')
c.pack(fill='both', expand='yes')
def motion(event):
if follow:
print(event.x, event.y)
follow = False
def follow_motion(event):
global follow
follow = not follow
c.bind('<Motion>', motion)
c.bind('<Button-1>', follow_motion)
root.mainloop()
Click the left mouse button on the canvas and the function motion() is enabled. One more click disables it.