add implementation of GS v 0, GS ( L and GS *.

- ported test cases for EscposImage class, copied over 1px and 2px test images from escpos-php
- added test cases over image print function
- updated QR tests to also include image output check
- updated CLI to match new image function options

test/test_function_image.py

@@ -0,0 +1,115 @@
+#!/usr/bin/env python
+""" Image function tests- Check that image print commands are sent correctly.
+
+: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
+"""
+
+import escpos.printer as printer
+from PIL import Image
+
+# Raster format print
+def test_bit_image_black():
+    """
+    Test printing solid black bit image (raster)
+    """
+    instance = printer.Dummy()
+    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 test_bit_image_white():
+    """
+    Test printing solid white bit image (raster)
+    """
+    instance = printer.Dummy()
+    instance.image('test/resources/canvas_white.png', impl="bitImageRaster")
+    assert(instance.output == b'\x1dv0\x00\x01\x00\x01\x00\x00')
+
+def test_bit_image_both():
+    """
+    Test printing black/white bit image (raster)
+    """
+    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')