Merge noio/python-escpos with latest google code

Merge branch 'master' of https://github.com/noio/python-escpos

Conflicts:
	escpos/__init__.py
	escpos/escpos.py
	escpos/exceptions.py
	escpos/printer.py

escpos/escpos.py

@@ -9,6 +9,8 @@
 import Image
 import qrcode
 import time
+import os
+import operator
 
 from constants import *
 from exceptions import *
@@ -51,8 +53,44 @@ class Escpos:
                 buffer = ""
                 cont = 0
 
+    def fullimage(self, img, max_height=860, width=512, histeq=True):
+        """ Resizes and prints an arbitrarily sized image """
+        if isinstance(img, Image.Image):
+            im = img.convert("RGB")
+        else:
+            im = Image.open(img).convert("RGB")
 
-    def _convert_image(self, im):
+        if histeq:
+            # Histogram equaliztion
+            h = im.histogram()
+            lut = []
+            for b in range(0, len(h), 256):
+                # step size
+                step = reduce(operator.add, h[b:b+256]) / 255
+                # create equalization lookup table
+                n = 0
+                for i in range(256):
+                    lut.append(n / step)
+                    n = n + h[i+b]
+            im = im.point(lut)
+
+        ratio = float(width) / im.size[0]
+        newheight = int(ratio * im.size[1])
+
+        # Resize the image
+        im = im.resize((width, newheight), Image.ANTIALIAS)
+        if im.size[1] > max_height:
+            im = im.crop((0, 0, im.size[0], max_height))
+
+        # Divide into bands
+        bandsize = 255
+        current = 0
+        while current < im.size[1]:
+            self.image(im.crop((0, current, width, min(im.size[1], current + bandsize))))
+            current += bandsize
+
+
+    def image(self, img):
         """ Parse image and prepare it to a printable format """
         pixels   = []
         pix_line = ""
@@ -61,9 +99,13 @@ class Escpos:
         switch   = 0
         img_size = [ 0, 0 ]
 
+        if isinstance(img, Image.Image):
+            im = img.convert("RGB")
+        else:
+            im = Image.open(img).convert("RGB")
 
         if im.size[0] > 512:
-            print  ("WARNING: Image is wider than 512 and could be truncated at print time ")
+            print  "WARNING: Image is wider than 512 and could be truncated at print time "
         if im.size[1] > 255:
             raise ImageSizeError()
 
@@ -99,15 +141,6 @@ class Escpos:
 
         self._print_image(pix_line, img_size)
 
-
-    def image(self,path_img):
-        """ Open image file """
-        im_open = Image.open(path_img)
-        im = im_open.convert("RGB")
-        # Convert the RGB image in printable image
-        self._convert_image(im)
-
-
     def qr(self,text):
         """ Print QR Code for the provided string """
         qr_code = qrcode.QRCode(version=4, box_size=4, border=1)
@@ -118,7 +151,6 @@ class Escpos:
         # Convert the RGB image in printable image
         self._convert_image(im)
 
-
     def barcode(self, code, bc, width, height, pos, font):
         """ Print Barcode """
         # Align Bar Code()
@@ -226,7 +258,6 @@ class Escpos:
         elif align.upper() == "LEFT":
             self._raw(TXT_ALIGN_LT)
 
-
     def cut(self, mode=''):
         """ Cut paper """
         # Fix the size between last line and cut

escpos/exceptions.py

@@ -14,6 +14,9 @@ class Error(Exception):
     def __str__(self):
         return self.msg
 
+class NotFoundError(Error):
+    """ Device wasn't found (not plugged in) """
+
 # Result/Exit codes
 # 0  = success
 # 10 = No Barcode type defined

escpos/printer.py

@@ -38,7 +38,7 @@ class Usb(Escpos):
         """ Search device on USB tree and set is as escpos device """
         self.device = usb.core.find(idVendor=self.idVendor, idProduct=self.idProduct)
         if self.device is None:
-            print "Cable isn't plugged in"
+            raise NotFoundError("Device not found or cable not plugged in.")
 
         if self.device.is_kernel_driver_active(0):
             try:
@@ -137,7 +137,6 @@ class Network(Escpos):
         self.device.close()
 
 
-
 class File(Escpos):
     """ Define Generic file printer """