def newImage(canvas):
    imageName=tkinter.filedialog.askopenfilename()
    filetype=""
    #make sure it's an image file
    try: filetype=imghdr.what(imageName)
    except:
        tkinter.messagebox.showinfo(title="Image File",\
        message="Choose an Image File!" , parent=canvas.data.mainWindow)
    # restrict filetypes to .jpg, .bmp, etc.
    if filetype in ['jpeg', 'bmp', 'png', 'tiff']:
        canvas.data.imageLocation=imageName
        im= Image.open(imageName)
        canvas.data.image=im
        canvas.data.originalImage=im.copy()
        canvas.data.undoQueue.append(im.copy())
        canvas.data.imageSize=im.size #Original Image dimensions
        canvas.data.imageForTk=makeImageForTk(canvas)
        drawImage(canvas)
    else:
        tkinter.messagebox.showinfo(title="Image File",\
        message="Choose an Image File!" , parent=canvas.data.mainWindow)