Merge pull request #128 from mike42/feature/rewrite-image-handling

Rewrite image handling

.travis.yml

@@ -20,7 +20,6 @@ matrix:
     - python: pypy3
       env: TOXENV=pypy3
   allow_failures:
-    - python: pypy3
     - python: 3.5-dev
     - python: nightly
 before_install:

escpos/cli.py

@@ -37,8 +37,8 @@ DEMO_FUNCTIONS = {
         {'txt': 'Hello, World!\n',}
     ],
     'qr': [
-        {'text': 'This tests a QR code'},
+        {'content': 'This tests a QR code'},
-        {'text': 'https://en.wikipedia.org/'}
+        {'content': 'https://en.wikipedia.org/'}
     ],
     'barcodes_a': [
         {'bc': 'UPC-A', 'code': '13243546576'},
@@ -87,7 +87,7 @@ ESCPOS_COMMANDS = [
         },
         'arguments': [
             {
-                'option_strings': ('--text',),
+                'option_strings': ('--content',),
                 'help': 'Text to print as a qr code',
                 'required': True,
             }
@@ -223,10 +223,26 @@ ESCPOS_COMMANDS = [
         },
         'arguments': [
             {
-                'option_strings': ('--path_img',),
+                'option_strings': ('--img_source',),
                 'help': 'Path to image',
                 'required': True,
             },
+            {
+                'option_strings': ('--impl',),
+                'help': 'Implementation to use',
+                'choices': ['bitImageRaster', 'bitImageColumn', 'graphics'],
+            },
+            {
+                'option_strings': ('--high_density_horizontal',),
+                'help': 'Image density (horizontal)',
+                'type': str_to_bool,
+            },     
+            {
+                'option_strings': ('--high_density_vertical',),
+                'help': 'Image density (vertical)',
+                'type': str_to_bool,
+            },      
+                      
         ],
     },
     {

escpos/constants.py

@@ -184,15 +184,15 @@ BARCODE_TYPES = {
 }
 
 ## QRCode error correction levels
-QR_ECLEVEL_L = 0;
+QR_ECLEVEL_L = 0
-QR_ECLEVEL_M = 1;
+QR_ECLEVEL_M = 1
-QR_ECLEVEL_Q = 2;
+QR_ECLEVEL_Q = 2
-QR_ECLEVEL_H = 3;
+QR_ECLEVEL_H = 3
     
 ## QRcode models
-QR_MODEL_1 = 1;
+QR_MODEL_1 = 1
-QR_MODEL_2 = 2;
+QR_MODEL_2 = 2
-QR_MICRO = 3;
+QR_MICRO = 3
 
 # Image format
 # NOTE: _PRINT_RASTER_IMG is the obsolete ESC/POS "print raster bit image"

escpos/escpos.py

@@ -14,20 +14,14 @@ from __future__ import division
 from __future__ import print_function
 from __future__ import unicode_literals
 
-import six
-
-from PIL import Image
-
 import qrcode
 import textwrap
-import binascii
-import operator
 
 from .constants import *
 from .exceptions import *
 
 from abc import ABCMeta, abstractmethod  # abstract base class support
-
+from escpos.image import EscposImage
 
 class Escpos(object):
     """ ESC/POS Printer object
@@ -55,213 +49,52 @@ class Escpos(object):
         """
         pass
 
-    @staticmethod
+    def image(self, img_source, high_density_vertical=True, high_density_horizontal=True, impl="bitImageRaster"):
-    def _check_image_size(size):
+        """ Print an image
-        """ Check and fix the size of the image to 32 bits
 
-        :param size: size of the image
+        :param img_source: PIL image or filename to load: `jpg`, `gif`, `png` or `bmp`
-        :returns: tuple of image borders
+        
-        :rtype: (int, int)
+        """       
+        im = EscposImage(img_source)
+        
+        if impl == "bitImageRaster":
+            # GS v 0, raster format bit image
+            density_byte = (0 if high_density_horizontal else 1) + (0 if high_density_vertical else 2)
+            header = GS + b"v0" + six.int2byte(density_byte) + self._int_low_high(im.width_bytes, 2) + self._int_low_high(im.height, 2)
+            self._raw(header + im.to_raster_format())
+        
+        if impl == "graphics":
+            # GS ( L raster format graphics
+            img_header = self._int_low_high(im.width, 2) + self._int_low_high(im.height, 2)
+            tone = b'0'
+            colors = b'1'
+            ym = six.int2byte(1 if high_density_vertical else 2)
+            xm = six.int2byte(1 if high_density_horizontal else 2)
+            header = tone + xm + ym + colors + img_header
+            raster_data = im.to_raster_format()
+            self._image_send_graphics_data(b'0', b'p', header + raster_data)
+            self._image_send_graphics_data(b'0', b'2', b'')
+        
+        if impl == "bitImageColumn":
+            # ESC *, column format bit image
+            density_byte = (1 if high_density_horizontal else 0) + (32 if high_density_vertical else 0)
+            header = ESC + b"*" + six.int2byte(density_byte) + self._int_low_high(im.width, 2)
+            outp = [ESC + b"3" + six.int2byte(16)]  # Adjust line-feed size
+            for blob in im.to_column_format(high_density_vertical):
+                outp.append(header + blob + b"\n")
+            outp.append(ESC + b"2")  # Reset line-feed size
+            self._raw(b''.join(outp))
+
+    def _image_send_graphics_data(self, m, fn, data):
         """
-        if size % 32 == 0:
+        Wrapper for GS ( L, to calculate and send correct data length.
-            return 0, 0
+        
-        else:
+        :param m: Modifier//variant for function. Usually '0'
-            image_border = 32 - (size % 32)
+        :param fn: Function number to use, as byte
-            if (image_border % 2) == 0:
+        :param data: Data to send
-                return image_border // 2, image_border // 2
-            else:
-                return image_border // 2, (image_border // 2) + 1
-
-    def _print_image(self, line, size):
-        """ Print formatted image
-
-        :param line:
-        :param size:
         """
-        i = 0
+        header = self._int_low_high(len(data) + 2, 2)
-        cont = 0
+        self._raw(GS + b'(L' + header + m + fn + data)
-        pbuffer = b''
-
-        self._raw(S_RASTER_N)
-        pbuffer = "{0:02X}{1:02X}{2:02X}{3:02X}".format(((size[0]//size[1])//8), 0, size[1] & 0xff, size[1] >> 8)
-        self._raw(binascii.unhexlify(pbuffer))
-        pbuffer = ""
-
-        while i < len(line):
-            hex_string = int(line[i:i+8], 2)
-            pbuffer += "{0:02X}".format(hex_string)
-            i += 8
-            cont += 1
-            if cont % 4 == 0:
-                self._raw(binascii.unhexlify(pbuffer))
-                pbuffer = ""
-                cont = 0
-
-    def _convert_image(self, im):
-        """ Parse image and prepare it to a printable format
-
-        :param im: image data
-        :raises: :py:exc:`~escpos.exceptions.ImageSizeError`
-        """
-        pixels = []
-        pix_line = ""
-        im_left = ""
-        im_right = ""
-        switch = 0
-        img_size = [0, 0]
-
-        if im.size[0] > 512:
-            print ("WARNING: Image is wider than 512 and could be truncated at print time ")
-        if im.size[1] > 0xffff:
-            raise ImageSizeError()
-
-        im_border = self._check_image_size(im.size[0])
-        for i in range(im_border[0]):
-            im_left += "0"
-        for i in range(im_border[1]):
-            im_right += "0"
-
-        for y in range(im.size[1]):
-            img_size[1] += 1
-            pix_line += im_left
-            img_size[0] += im_border[0]
-            for x in range(im.size[0]):
-                img_size[0] += 1
-                RGB = im.getpixel((x, y))
-                im_color = (RGB[0] + RGB[1] + RGB[2])
-                im_pattern = "1X0"
-                pattern_len = len(im_pattern)
-                switch = (switch - 1) * (-1)
-                for x in range(pattern_len):
-                    if im_color <= (255 * 3 / pattern_len * (x+1)):
-                        if im_pattern[x] == "X":
-                            pix_line += "{0:d}".format(switch)
-                        else:
-                            pix_line += im_pattern[x]
-                        break
-                    elif (255 * 3 / pattern_len * pattern_len) < im_color <= (255 * 3):
-                        pix_line += im_pattern[-1]
-                        break
-            pix_line += im_right
-            img_size[0] += im_border[1]
-
-        self._print_image(pix_line, img_size)
-
-    def image(self, path_img):
-        """ Open and print an image file
-
-        Prints an image. The image is automatically adjusted in size in order to print it.
-
-        .. todo:: Seems to be broken. Write test that simply executes function with a dummy printer in order to
-                  check for bugs like these in the future.
-
-        :param path_img: complete filename and path to image of type `jpg`, `gif`, `png` or `bmp`
-        """
-        if not isinstance(path_img, Image.Image):
-            im_open = Image.open(path_img)
-        else:
-            im_open = path_img
-
-        # Remove the alpha channel on transparent images
-        if im_open.mode == 'RGBA':
-            im_open.load()
-            im = Image.new("RGB", im_open.size, (255, 255, 255))
-            im.paste(im_open, mask=im_open.split()[3])
-        else:
-            im = im_open.convert("RGB")
-
-        # Convert the RGB image in printable image
-        self._convert_image(im)
-
-    def fullimage(self, img, max_height=860, width=512, histeq=True, bandsize=255):
-        """ Resizes and prints an arbitrarily sized image
-
-        .. warning:: The image-printing-API is currently under development. Please do not consider this method part
-                     of the API. It might be subject to change without further notice.
-
-        .. todo:: Seems to be broken. Write test that simply executes function with a dummy printer in order to
-                  check for bugs like these in the future.
-        """
-        print("WARNING: The image-printing-API is currently under development. Please do not consider this "
-              "function part of the API yet.")
-        if isinstance(img, Image.Image):
-            im = img.convert("RGB")
-        else:
-            im = Image.open(img).convert("RGB")
-
-        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)
-
-        if width:
-            ratio = float(width) / im.size[0]
-            newheight = int(ratio * im.size[1])
-
-            # Resize the image
-            im = im.resize((width, newheight), Image.ANTIALIAS)
-
-        if max_height and im.size[1] > max_height:
-            im = im.crop((0, 0, im.size[0], max_height))
-
-        # Divide into bands
-        current = 0
-        while current < im.size[1]:
-            self.image(im.crop((0, current, width or im.size[0],
-                                min(im.size[1], current + bandsize))))
-            current += bandsize
-
-    def direct_image(self, image):
-        """ Direct printing function for pictures
-
-        .. warning:: The image-printing-API is currently under development. Please do not consider this method part
-                     of the API. It might be subject to change without further notice.
-
-        This function is rather fragile and will fail when the Image object is not suited.
-
-        :param image: PIL image object, containing a 1-bit picture
-        """
-        print("WARNING: The image-printing-API is currently under development. Please do not consider this "
-              "function part of the API yet.")
-        mask = 0x80
-        i = 0
-        temp = 0
-
-        (width, height) = image.size
-        self._raw(S_RASTER_N)
-        header_x = int(width / 8)
-        header_y = height
-        buf = "{0:02X}".format((header_x & 0xff))
-        buf += "{0:02X}".format(((header_x >> 8) & 0xff))
-        buf += "{0:02X}".format((header_y & 0xff))
-        buf += "{0:02X}".format(((header_y >> 8) & 0xff))
-        #self._raw(binascii.unhexlify(buf))
-        for y in range(height):
-            for x in range(width):
-                value = image.getpixel((x, y))
-                value |= (value << 8)
-                if value == 0:
-                    temp |= mask
-
-                mask >>= 1
-
-                i += 1
-                if i == 8:
-                    buf += ("{0:02X}".format(temp))
-                    mask = 0x80
-                    i = 0
-                    temp = 0
-        self._raw(binascii.unhexlify(bytes(buf, "ascii")))
-        self._raw(b'\n')
 
     def qr(self, content, ec=QR_ECLEVEL_L, size=3, model=QR_MODEL_2, native=False):
         """ Print QR Code for the provided string
@@ -286,7 +119,7 @@ class Escpos(object):
         if not native:
             # Map ESC/POS error correction levels to python 'qrcode' library constant and render to an image
             if model != QR_MODEL_2:
-                raise ValueError("Invalid QR mocel for qrlib rendering (must be QR_MODEL_2)")
+                raise ValueError("Invalid QR model for qrlib rendering (must be QR_MODEL_2)")
             python_qr_ec = {
                      QR_ECLEVEL_H: qrcode.constants.ERROR_CORRECT_H,
                      QR_ECLEVEL_L: qrcode.constants.ERROR_CORRECT_L,
@@ -299,19 +132,19 @@ class Escpos(object):
             qr_img = qr_code.make_image()
             im = qr_img._img.convert("RGB")
             # Convert the RGB image in printable image
-            self._convert_image(im)
+            self.image(im)
             return
         # Native 2D code printing
-        cn = b'1' # Code type for QR code
+        cn = b'1'  # Code type for QR code
         # Select model: 1, 2 or micro.
-        self._send_2d_code_data(six.int2byte(65), cn, six.int2byte(48 + model) + six.int2byte(0));
+        self._send_2d_code_data(six.int2byte(65), cn, six.int2byte(48 + model) + six.int2byte(0))
         # Set dot size.
-        self._send_2d_code_data(six.int2byte(67), cn, six.int2byte(size));
+        self._send_2d_code_data(six.int2byte(67), cn, six.int2byte(size))
         # Set error correction level: L, M, Q, or H
-        self._send_2d_code_data(six.int2byte(69), cn, six.int2byte(48 + ec));
+        self._send_2d_code_data(six.int2byte(69), cn, six.int2byte(48 + ec))
         # Send content & print
-        self._send_2d_code_data(six.int2byte(80), cn, content.encode('utf-8'), b'0');
+        self._send_2d_code_data(six.int2byte(80), cn, content.encode('utf-8'), b'0')
-        self._send_2d_code_data(six.int2byte(81), cn, b'', b'0');
+        self._send_2d_code_data(six.int2byte(81), cn, b'', b'0')
 
     def _send_2d_code_data(self, fn, cn, data, m=b''):
         """ Wrapper for GS ( k, to calculate and send correct data length.
@@ -323,7 +156,7 @@ class Escpos(object):
         """
         if len(m) > 1 or len(cn) != 1 or len(fn) != 1:
             raise ValueError("cn and fn must be one byte each.")
-        header = self._int_low_high(len(data) + len(m) + 2, 2);
+        header = self._int_low_high(len(data) + len(m) + 2, 2)
         self._raw(GS + b'(k' + header + cn + fn + m + data)
     
     @staticmethod
@@ -333,12 +166,12 @@ class Escpos(object):
         :param inp_number: Input number
         :param out_bytes: The number of bytes to output (1 - 4).
         """
-        max_input = (256 << (out_bytes * 8) - 1);
+        max_input = (256 << (out_bytes * 8) - 1)
         if not 1 <= out_bytes <= 4:
             raise ValueError("Can only output 1-4 byes")
         if not 0 <= inp_number <= max_input:
             raise ValueError("Number too large. Can only output up to {0} in {1} byes".format(max_input, out_bytes))
-        outp = b'';
+        outp = b''
         for _ in range(0, out_bytes):
             outp += six.int2byte(inp_number % 256)
             inp_number = inp_number // 256

escpos/image.py

@@ -0,0 +1,90 @@
+""" Image format handling class
+
+This module contains the image format handler :py:class:`EscposImage`.
+
+:author: `Michael Billington <michael.billington@gmail.com>`_
+:organization: `python-escpos <https://github.com/python-escpos>`_
+:copyright: Copyright (c) 2016 Michael Billington <michael.billington@gmail.com>
+:license: GNU GPL v3
+"""
+
+from PIL import Image, ImageOps
+
+
+class EscposImage(object):
+    """
+    Load images in, and output ESC/POS formats.
+
+    The class is designed to efficiently delegate image processing to
+    PIL, rather than spend CPU cycles looping over pixels.
+    """
+
+    def __init__(self, img_source):
+        """
+        Load in an image
+        
+        :param img_source: PIL.Image, or filename to load one from.
+        """
+        if isinstance(img_source, Image.Image):
+            img_original = img_source
+        else:
+            img_original = Image.open(img_source)
+
+        # Convert to white RGB background, paste over white background
+        # to strip alpha.
+        img_original = img_original.convert('RGBA')
+        im = Image.new("RGB", img_original.size, (255, 255, 255))
+        im.paste(img_original, mask=img_original.split()[3])
+        # Convert down to greyscale
+        im = im.convert("L") 
+        # Invert: Only works on 'L' images
+        im = ImageOps.invert(im)
+        # Pure black and white
+        self._im = im.convert("1")
+    
+    @property
+    def width(self):
+        """
+        Width of image in pixels
+        """
+        width_pixels, _ = self._im.size
+        return width_pixels
+
+    @property
+    def width_bytes(self):
+        """
+        Width of image if you use 8 pixels per byte and 0-pad at the end.
+        """
+        return (self.width + 7) >> 3
+
+    @property
+    def height(self):
+        """
+        Height of image in pixels
+        """
+        _, height_pixels = self._im.size
+        return height_pixels
+
+    def to_column_format(self, high_density_vertical=True):
+        """
+        Extract slices of an image as equal-sized blobs of column-format data.
+
+        :param high_density_vertical: Printed line height in dots
+        """
+        im = self._im.transpose(Image.ROTATE_270).transpose(Image.FLIP_LEFT_RIGHT)
+        line_height = 24 if high_density_vertical else 8
+        width_pixels, height_pixels = im.size
+        top = 0
+        left = 0
+        while left < width_pixels:
+            box = (left, top, left + line_height, top + height_pixels)
+            im_slice = im.transform((line_height, height_pixels), Image.EXTENT, box)
+            im_bytes = im_slice.tobytes()
+            yield(im_bytes)
+            left += line_height
+
+    def to_raster_format(self):
+        """
+        Convert image to raster-format binary
+        """
+        return self._im.tobytes()

escpos/printer.py

@@ -20,7 +20,6 @@ import socket
 from .escpos import Escpos
 from .exceptions import *
 
-
 class Usb(Escpos):
     """ USB printer
 
@@ -260,3 +259,38 @@ class File(Escpos):
         """ Close system file """
         self.device.flush()
         self.device.close()
+
+class Dummy(Escpos):
+    """ Dummy printer
+
+    This class is used for saving commands to a variable, for use in situations where
+    there is no need to send commands to an actual printer. This includes
+    generating print jobs for later use, or testing output.
+
+    inheritance:
+
+    .. inheritance-diagram:: escpos.printer.Dummy
+        :parts: 1
+
+    """
+
+    def __init__(self, *args, **kwargs):
+        """
+
+        :param devfile : Device file under dev filesystem
+        """
+        Escpos.__init__(self, *args, **kwargs)
+        self._output_list = []
+
+    def _raw(self, msg):
+        """ Print any command sent in raw format
+
+        :param msg: arbitrary code to be printed
+        :type msg: bytes
+        """
+        self._output_list.append(msg)
+
+    @property
+    def output(self):
+        """ Get the data that was sent to this printer """
+        return b''.join(self._output_list)

test/test_function_image.py

@@ -1,9 +1,9 @@
-#!/usr/bin/python
+#!/usr/bin/env python
-"""tests for the image printing function
+""" Image function tests- Check that image print commands are sent correctly.
 
-:author: `Patrick Kanzler <patrick.kanzler@fablab.fau.de>`_
+:author: `Michael Billington <michael.billington@gmail.com>`_
 :organization: `python-escpos <https://github.com/python-escpos>`_
-:copyright: Copyright (c) 2016 `python-escpos <https://github.com/python-escpos>`_
+:copyright: Copyright (c) 2016 `Michael Billington <michael.billington@gmail.com>`_
 :license: GNU GPL v3
 """
 
@@ -12,39 +12,121 @@ from __future__ import division
 from __future__ import print_function
 from __future__ import unicode_literals
 
-from nose.tools import with_setup
-
 import escpos.printer as printer
-import os
+from PIL import Image
 
-devfile = 'testfile'
 
-def setup_testfile():
+# Raster format print
-    """create a testfile as devfile"""
+def test_bit_image_black():
-    fhandle = open(devfile, 'a')
+    """
-    try:
+    Test printing solid black bit image (raster)
-        os.utime(devfile, None)
+    """
-    finally:
+    instance = printer.Dummy()
-        fhandle.close()
+    instance.image('test/resources/canvas_black.png', impl="bitImageRaster")
+    assert(instance.output == b'\x1dv0\x00\x01\x00\x01\x00\x80')
+    # Same thing w/ object created on the fly, rather than a filename
+    instance = printer.Dummy()
+    im = Image.new("RGB", (1, 1), (0, 0, 0))
+    instance.image(im, impl="bitImageRaster")
+    assert(instance.output == b'\x1dv0\x00\x01\x00\x01\x00\x80')
 
-def teardown_testfile():
-    """destroy testfile again"""
-    os.remove(devfile)
 
-@with_setup(setup_testfile, teardown_testfile)
+def test_bit_image_white():
-def test_function_image_with_50x50_png():
+    """
-    """test the image function with 50x50.png (grayscale png)"""
+    Test printing solid white bit image (raster)
-    instance = printer.File(devfile=devfile)
+    """
-    instance.image("test/50x50.png")
+    instance = printer.Dummy()
+    instance.image('test/resources/canvas_white.png', impl="bitImageRaster")
+    assert(instance.output == b'\x1dv0\x00\x01\x00\x01\x00\x00')
 
-@with_setup(setup_testfile, teardown_testfile)
-def test_function_image_with_255x255_png():
-    """test the image function with 255x255.png (grayscale png)"""
-    instance = printer.File(devfile=devfile)
-    instance.image("test/255x255.png")
 
-@with_setup(setup_testfile, teardown_testfile)
+def test_bit_image_both():
-def test_function_image_with_400x400_png():
+    """
-    """test the image function with 400x400.png (grayscale png)"""
+    Test printing black/white bit image (raster)
-    instance = printer.File(devfile=devfile)
+    """
-    instance.image("test/400x400.png")
+    instance = printer.Dummy()
+    instance.image('test/resources/black_white.png', impl="bitImageRaster")
+    assert(instance.output == b'\x1dv0\x00\x01\x00\x02\x00\xc0\x00')
+
+
+def test_bit_image_transparent():
+    """
+    Test printing black/transparent bit image (raster)
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/black_transparent.png', impl="bitImageRaster")
+    assert(instance.output == b'\x1dv0\x00\x01\x00\x02\x00\xc0\x00')
+
+
+# Column format print
+def test_bit_image_colfmt_black():
+    """
+    Test printing solid black bit image (column format)
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/canvas_black.png', impl="bitImageColumn")
+    assert(instance.output == b'\x1b3\x10\x1b*!\x01\x00\x80\x00\x00\x0a\x1b2')
+
+
+def test_bit_image_colfmt_white():
+    """
+    Test printing solid white bit image (column format)
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/canvas_white.png', impl="bitImageColumn")
+    assert(instance.output == b'\x1b3\x10\x1b*!\x01\x00\x00\x00\x00\x0a\x1b2')
+
+
+def test_bit_image_colfmt_both():
+    """
+    Test printing black/white bit image (column format)
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/black_white.png', impl="bitImageColumn")
+    assert(instance.output == b'\x1b3\x10\x1b*!\x02\x00\x80\x00\x00\x80\x00\x00\x0a\x1b2')
+
+
+def test_bit_image_colfmt_transparent():
+    """
+    Test printing black/transparent bit image (column format)
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/black_transparent.png', impl="bitImageColumn")
+    assert(instance.output == b'\x1b3\x10\x1b*!\x02\x00\x80\x00\x00\x80\x00\x00\x0a\x1b2')
+
+
+# Graphics print
+def test_graphics_black():
+    """
+    Test printing solid black graphics
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/canvas_black.png', impl="graphics")
+    assert(instance.output == b'\x1d(L\x0b\x000p0\x01\x011\x01\x00\x01\x00\x80\x1d(L\x02\x0002')
+
+
+def test_graphics_white():
+    """
+    Test printing solid white graphics
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/canvas_white.png', impl="graphics")
+    assert(instance.output == b'\x1d(L\x0b\x000p0\x01\x011\x01\x00\x01\x00\x00\x1d(L\x02\x0002')
+
+
+def test_graphics_both():
+    """
+    Test printing black/white graphics
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/black_white.png', impl="graphics")
+    assert(instance.output == b'\x1d(L\x0c\x000p0\x01\x011\x02\x00\x02\x00\xc0\x00\x1d(L\x02\x0002')
+
+
+def test_graphics_transparent():
+    """
+    Test printing black/transparent graphics
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/black_transparent.png', impl="graphics")
+    assert(instance.output == b'\x1d(L\x0c\x000p0\x01\x011\x02\x00\x02\x00\xc0\x00\x1d(L\x02\x0002')

test/test_function_qr_native.py

@@ -12,70 +12,88 @@ from __future__ import division
 from __future__ import print_function
 from __future__ import unicode_literals
 
-from nose.tools import with_setup
+from nose.tools import raises
-
 import escpos.printer as printer
-import os
 from escpos.constants import QR_ECLEVEL_H, QR_MODEL_1
 
-devfile = 'testfile'
 
-
+def test_defaults():
-def setup_testfile():
+    """Test QR code with defaults"""
-    """create a testfile as devfile"""
+    instance = printer.Dummy()
-    fhandle = open(devfile, 'a')
-    try:
-        os.utime(devfile, None)
-    finally:
-        fhandle.close()
-
-
-def teardown_testfile():
-    """destroy testfile again"""
-    os.remove(devfile)
-
-
-@with_setup(setup_testfile, teardown_testfile)
-def test_function_qr_defaults():
-    """test QR code with defaults"""
-    instance = printer.File(devfile=devfile)
     instance.qr("1234", native=True)
-    instance.flush()
+    expected = b'\x1d(k\x04\x001A2\x00\x1d(k\x03\x001C\x03\x1d(k\x03\x001E0\x1d' \
-    with open(devfile, "rb") as f:
+        b'(k\x07\x001P01234\x1d(k\x03\x001Q0'
-        assert(f.read() == b'\x1d(k\x04\x001A2\x00\x1d(k\x03\x001C\x03\x1d(k\x03\x001E0\x1d(k\x07\x001P01234\x1d(k\x03\x001Q0')
+    assert(instance.output == expected)
 
-@with_setup(setup_testfile, teardown_testfile)
+
-def test_function_qr_empty():
+def test_empty():
-    """test QR printing blank code"""
+    """Test QR printing blank code"""
-    instance = printer.File(devfile=devfile)
+    instance = printer.Dummy()
     instance.qr("", native=True)
-    instance.flush()
+    assert(instance.output == b'')
-    with open(devfile, "rb") as f:
-        assert(f.read() == b'')
 
-@with_setup(setup_testfile, teardown_testfile)
+
-def test_function_qr_ec():
+def test_ec():
-    """test QR error correction setting"""
+    """Test QR error correction setting"""
-    instance = printer.File(devfile=devfile)
+    instance = printer.Dummy()
     instance.qr("1234", native=True, ec=QR_ECLEVEL_H)
-    instance.flush()
+    expected = b'\x1d(k\x04\x001A2\x00\x1d(k\x03\x001C\x03\x1d(k\x03\x001E3\x1d' \
-    with open(devfile, "rb") as f:
+        b'(k\x07\x001P01234\x1d(k\x03\x001Q0'
-        assert(f.read() == b'\x1d(k\x04\x001A2\x00\x1d(k\x03\x001C\x03\x1d(k\x03\x001E3\x1d(k\x07\x001P01234\x1d(k\x03\x001Q0')
+    assert(instance.output == expected)
 
-@with_setup(setup_testfile, teardown_testfile)
+
-def test_function_qr_size():
+def test_size():
-    """test QR box size"""
+    """Test QR box size"""
-    instance = printer.File(devfile=devfile)
+    instance = printer.Dummy()
     instance.qr("1234", native=True, size=7)
-    instance.flush()
+    expected = b'\x1d(k\x04\x001A2\x00\x1d(k\x03\x001C\x07\x1d(k\x03\x001E0\x1d' \
-    with open(devfile, "rb") as f:
+        b'(k\x07\x001P01234\x1d(k\x03\x001Q0'
-        assert(f.read() == b'\x1d(k\x04\x001A2\x00\x1d(k\x03\x001C\x07\x1d(k\x03\x001E0\x1d(k\x07\x001P01234\x1d(k\x03\x001Q0')
+    assert(instance.output == expected)
 
-@with_setup(setup_testfile, teardown_testfile)
+
-def test_function_qr_model():
+def test_model():
-    """test QR model"""
+    """Test QR model"""
-    instance = printer.File(devfile=devfile)
+    instance = printer.Dummy()
     instance.qr("1234", native=True, model=QR_MODEL_1)
-    instance.flush()
+    expected = b'\x1d(k\x04\x001A1\x00\x1d(k\x03\x001C\x03\x1d(k\x03\x001E0\x1d' \
-    with open(devfile, "rb") as f:
+        b'(k\x07\x001P01234\x1d(k\x03\x001Q0'
-        assert(f.read() == b'\x1d(k\x04\x001A1\x00\x1d(k\x03\x001C\x03\x1d(k\x03\x001E0\x1d(k\x07\x001P01234\x1d(k\x03\x001Q0')
+    assert(instance.output == expected)
+
+
+@raises(ValueError)
+def test_invalid_ec():
+    """Test invalid QR error correction"""
+    instance = printer.Dummy()
+    instance.qr("1234", native=True, ec=-1)
+
+
+@raises(ValueError)
+def test_invalid_size():
+    """Test invalid QR size"""
+    instance = printer.Dummy()
+    instance.qr("1234", native=True, size=0)
+
+
+@raises(ValueError)
+def test_invalid_model():
+    """Test invalid QR model"""
+    instance = printer.Dummy()
+    instance.qr("1234", native=True, model="Hello")
+
+
+def test_image():
+    """Test QR as image"""
+    instance = printer.Dummy()
+    instance.qr("1", native=False, size=1)
+    print(instance.output)
+    expected = b'\x1dv0\x00\x03\x00\x17\x00\x00\x00\x00\x7f]\xfcA\x19\x04]it]et' \
+        b']ItA=\x04\x7fU\xfc\x00\x0c\x00y~t4\x7f =\xa84j\xd9\xf0\x05\xd4\x90\x00' \
+        b'i(\x7f<\xa8A \xd8]\'\xc4]y\xf8]E\x80Ar\x94\x7fR@\x00\x00\x00'
+    assert(instance.output == expected)
+
+
+@raises(ValueError)
+def test_image_invalid_model():
+    """Test unsupported QR model as image"""
+    instance = printer.Dummy()
+    instance.qr("1234", native=False, model=QR_MODEL_1)

test/test_image.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python
+""" Image tests- Check that images from different source formats are correctly
+converted to ESC/POS column & raster formats.
+
+:author: `Michael Billington <michael.billington@gmail.com>`_
+:organization: `python-escpos <https://github.com/python-escpos>`_
+:copyright: Copyright (c) 2016 `Michael Billington <michael.billington@gmail.com>`_
+:license: GNU GPL v3
+"""
+
+from escpos.image import EscposImage
+
+
+def test_image_black():
+    """
+    Test rendering solid black image
+    """
+    for img_format in ['png', 'jpg', 'gif']:
+        _load_and_check_img('canvas_black.' + img_format, 1, 1, b'\x80', [b'\x80'])
+
+
+def test_image_black_transparent():
+    """
+    Test rendering black/transparent image
+    """
+    for img_format in ['png', 'gif']:
+        _load_and_check_img('black_transparent.' + img_format, 2, 2, b'\xc0\x00', [b'\x80\x80'])
+
+
+def test_image_black_white():
+    """
+    Test rendering black/white image
+    """
+    for img_format in ['png', 'jpg', 'gif']:
+        _load_and_check_img('black_white.' + img_format, 2, 2, b'\xc0\x00', [b'\x80\x80'])
+
+
+def test_image_white():
+    """
+    Test rendering solid white image
+    """
+    for img_format in ['png', 'jpg', 'gif']:
+        _load_and_check_img('canvas_white.' + img_format, 1, 1, b'\x00', [b'\x00'])
+
+
+def _load_and_check_img(filename, width_expected, height_expected, raster_format_expected, column_format_expected):
+    """
+    Load an image, and test whether raster & column formatted output, sizes, etc match expectations.
+    """
+    im = EscposImage('test/resources/' + filename)
+    assert(im.width == width_expected)
+    assert(im.height == height_expected)
+    assert(im.to_raster_format() == raster_format_expected)
+    i = 0 
+    for row in im.to_column_format(False):
+        assert(row == column_format_expected[i])
+        i = i + 1