Generates TFW or JGW file from Tif and jpg image

TFW maker.py

from Tkinter import *
from tkMessageBox import showerror
from tkFileDialog import askopenfilename
class Application(Frame):
	"""A GUI to Generate Tfw file from Tiff File """

	def __init__(self,master):
		"""Initializes the frame"""
		Frame.__init__(self, master)
		self.grid()
		self.create_widgets()

	def create_widgets(self):
		"""Create buttons that do nothing"""

		#create label for scale factor
		self.sf=Label(self, text="Scale of map:",width=15)
		self.sf.grid(row=0, column=0, sticky=E+W+N+S)

		#create entry for scale factor
		self.sfentry= Entry(self,width=15)
		self.sfentry.grid(row=0, column =1, sticky=E+W+N+S)

		 #create label for scanning resolution
		self.dpi=Label(self, text="Resolution of Image",width=15)
		self.dpi.grid(row=1, column=0, sticky=E+W+N+S)

		#create entry for scale factor
		self.dpientry= Entry(self,width=15)
		self.dpientry.grid(row=1, column =1, sticky=E+W+N+S)
		
		#create browse label
		self.browse= Label(self, text = "Choose File", width = 15)
		self.browse.grid(row=2, column =0, sticky= E+W+N+S)
		
		#create button for file selection
		self.browsebutton=Button(self, text= "Browse file", command =self.filebrowser, width = 15)
		self.browsebutton.grid(row = 2, column= 1, sticky = E+W+N+S)

		#create Generate button
		self.button3=Button(self, text="Generate", command=self.tfwmaker, width=30)
		self.button3.grid(row=3, column=0, columnspan=2, sticky=E+W+N+S)

		self.status= StringVar()
		self.statusbar = Label(self, textvariable = self.status, width = 15)
		self.statusbar.grid(row=4, column =0, columnspan=2, sticky= E+W+N+S)
		  
	def filebrowser(self):
		import os
		global filename, location, directory, extension
		from tkFileDialog import askopenfilename
		Tk().withdraw()
		self.filename = askopenfilename()
		print type(self.filename)
		self.directory = os.path.dirname(os.path.realpath(self.filename))
		self.name = os.path.splitext(os.path.basename(self.filename))[0]
		self.extension = self.filename.rsplit(".",1)[-1]
		print self.extension
		os.chdir(self.directory)
		print self.filename, self.directory, self.name, os.getcwd(), self.extension
		self.location=Text(self, fg = 'green', height = 3)
		self.location.insert(INSERT,self.filename)
		self.location.grid( row = 2, column = 1, sticky = E+W+N+S)

	#make tfw for image
	def tfwmaker(self):
		import os, time
		import tkMessageBox
		global sf,dpi,cellsize ,errormessage
		if self.sfentry.get():
			sf = float(self.sfentry.get())
		else:
			self.status.set("Scale Factor value empty")
			# sf = 2500 #for development purpose only, change it in production
		if self.dpientry.get():
			dpi = float(self.dpientry.get())
		else:
			self.status.set("DPI value empty")
			# dpi = 96 #for development purpose only, change it in production
		cellsize = 0.0254*sf/dpi
		# print cellsize 
		# print "\n"
		# print self.extension

		#create a new tfw file and write it
		if self.extension == "tiff" or self.extension == "tif" or self.extension == "TIF" or self.extension == "TIFF" :
			self.outfile = open(self.name+".tfw","w")
		elif self.extension == "jpeg" or self.extension == "jpg" or self.extension == "JPEG" or self.extension == "JPG":
			self.outfile = open(self.name+".jgw","w")
		self.outfile.write(str(cellsize))
		self.outfile.write("\n0\n")
		self.outfile.write("0\n")
		self.outfile.write(str(-cellsize))
		self.outfile.write("\n500000\n")
		self.outfile.write("3100000")

		# Result Display
		self.status.set("World File Generated in " + str(self.directory) + "\\" + str(self.outfile.name))
		self.outfile.close()

root = Tk()
root.title("World file Maker")

app = Application(root)
root.mainloop()