Encountering the error message "Global name 'start' is not defined" from the code snippet provided. Interestingly, the call to start(panel) within displayImage(img) is responsible for displaying the desired image in the GUI; without it, no image appears. Despite this functionality, the aforementioned error arises. The program is being executed on Ubuntu 12.04 and I am a newcomer to both Python and Tkinter. Any suggestions for resolving this issue? Edit: Image addition takes place during runtime triggered by a button click that invokes loadPicture(file).
import numpy as np
from Tkinter import *
import cv2 as cv
from tkFileDialog import askopenfilename
import tkSimpleDialog as td
import math as mt
from PIL import ImageTk, Image
### General functions #############################################
def raiseFileChooser():
global filename
filename = askopenfilename()
loadPicture(filename)
def loadPicture(file):
# set global variable for other uses
global img
img = cv.imread(file, 1)
img = cv.cvtColor(img, cv.COLOR_RGB2BGR)
displayImage(img, display1)
def displayImage(image, panel):
temp = Image.fromarray(image)
bk = ImageTk.PhotoImage(temp)
bkLabel = Label(display1, image = bk)
bkLabel.place(x=0, y=0, relwidth=1, relheight=1)
start(panel)
### Start App ###########################################
#### get GUI started
root = Tk()
np.set_printoptions(threshold=np.nan) # so I can print entire arrays
### global variables ####################################
relStatus = StringVar()
relStatus.set(None)
text = StringVar()
filepath = StringVar()
filename = "No file chosen"
img = None
gsc = None
eStatus = StringVar()
eStatus.set(None)
display1 = None
display2 = None
### GUI #################################################
root.title("Picture Transformer")
root.geometry("700x600")
app = PanedWindow(root)
app.pack(padx=20, pady=20)
#Button Panel##############
buttonPanel = Frame(app,width=200, height = 400)
buttonPanel.pack(side=LEFT)
chooser = Button(buttonPanel, text="Choose File", height=1, width=9, command=raiseFileChooser)
chooser.pack()
#set up display panels ###########################
display1 = Frame(app, width=900, height=900, bg="#cccccc")
display1.pack(side=LEFT, fill=BOTH, expand=1)
root.mainloop()
Edit: Stacktrace:
Traceback (most recent call last):
File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1413, in __call__
return self.func(*args)
File "hw2.py", line 78, in raiseFileChooser
loadPicture(filename)
File "hw2.py", line 86, in loadPicture
start(panel)
NameError: global name 'start' is not defined