add print small image method for thermal/roll printer

screenless/bureau/bureau.py

@@ -11,7 +11,9 @@ import threading
 import time
 
 import lmdb
+import PIL
 import zmq
+from escpos import printer
 from mako.template import Template
 
 
@@ -239,6 +241,7 @@ class Bureau(object):
         print on Thermal Line printer.
         """
         # TODO: look up device and width in config
+        # TODO: refactor this to use escpos library
         lp = open(printer, "w")
         text = textwrap.fill(text, width=32)
         text += "\r\n" * 5 
@@ -246,6 +249,18 @@ class Bureau(object):
         lp.write(text)
         lp.close()
 
+    def print_small_image(self, img):
+        """
+        print an image on the mini thermal printer.
+        """
+        # TODO: make printer id/width configured and easy
+        prn = printer.Usb(0x416, 0x5011)
+        im = PIL.Image.open(img)
+        # NOTE: might be worth tring to push up brightness
+        im = PIL.ImageOps.equalize(im)  # stretch histogram for nicer dither
+        im.thumbnail((384, 384), PIL.Image.ANTIALIAS)  # resize to fit printer
+        prn.image(im, impl="bitImageColumn")  # not using this impl crashes ??
+
     @add_command("test")
     def test(self, data=None):
         """