I don’t have much time to write (I have a million things to do over this spring break!) but I’ll try to post what I discover as I go with the hope that it might help someone else out there. It’s amazing how simple this program is, and it’s frustrating how long it took me to figure out how to code the darn image viewer thing. So, for what it’s worth, here it is.

This little Python program will load an image (pretty much any format) using the Python Imaging Library (which must be installed) and allows you to see it on a scrollable canvas (in two directions) with Tkinter and ImageTk. The above screenshot is of the program viewing the image below:

What is that image? I won’t get ahead of myself, but it’s about 5kHz above 10.140mHz (30m radio band) including a popular QRSS calling frequency representing an entire hour of data. Also, I did all of the math myself with my own python scripts (yes, it eats WAV files and spits out spectrographs). Note that the JPG I uplaoded “full size” is no where near the ACTUAL full size of the image. It’s gagillions of pixels in all directions. Sweet. My goal is to have it scroll in the TK window, with slide-adjustable brightness/contrast/etc. I’ll get there eventually.

from Tkinter import *
import Image, ImageTk

class ScrolledCanvas(Frame):
     def __init__(self, parent=None):
          Frame.__init__(self, parent)
          self.master.title("Spectrogram Viewer")
          self.pack(expand=YES, fill=BOTH)
          canv = Canvas(self, relief=SUNKEN)
          canv.config(width=400, height=200)
          #canv.config(scrollregion=(0,0,1000, 1000))
          #canv.configure(scrollregion=canv.bbox('all'))
          canv.config(highlightthickness=0)

          sbarV = Scrollbar(self, orient=VERTICAL)
          sbarH = Scrollbar(self, orient=HORIZONTAL)

          sbarV.config(command=canv.yview)
          sbarH.config(command=canv.xview)

          canv.config(yscrollcommand=sbarV.set)
          canv.config(xscrollcommand=sbarH.set)

          sbarV.pack(side=RIGHT, fill=Y)
          sbarH.pack(side=BOTTOM, fill=X)

          canv.pack(side=LEFT, expand=YES, fill=BOTH)
          self.im=Image.open("./1hr_original.jpg")
          width,height=self.im.size
          canv.config(scrollregion=(0,0,width,height))
          self.im2=ImageTk.PhotoImage(self.im)
          self.imgtag=canv.create_image(0,0,anchor="nw",image=self.im2)

ScrolledCanvas().mainloop()