Source code for brother_ql.conversion

#!/usr/bin/env python

from __future__ import division, unicode_literals
from builtins import str

import logging

from PIL import Image
import PIL.ImageOps, PIL.ImageChops

from brother_ql.raster import BrotherQLRaster
from brother_ql.devicedependent import label_type_specs, ENDLESS_LABEL, DIE_CUT_LABEL, ROUND_DIE_CUT_LABEL, right_margin_addition
from brother_ql import BrotherQLUnsupportedCmd
from brother_ql.image_trafos import filtered_hsv

logger = logging.getLogger(__name__)


[docs]def convert(qlr, images, label, **kwargs): r"""Converts one or more images to a raster instruction file. :param qlr: An instance of the BrotherQLRaster class :type qlr: :py:class:`brother_ql.raster.BrotherQLRaster` :param images: The images to be converted. They can be filenames or instances of Pillow's Image. :type images: list(PIL.Image.Image) or list(str) images :param str label: Type of label the printout should be on. :param \**kwargs: See below :Keyword Arguments: * **cut** (``bool``) -- Enable cutting after printing the labels. * **dither** (``bool``) -- Instead of applying a threshold to the pixel values, approximate grey tones with dithering. * **compress** * **red** * **rotate** * **dpi_600** * **hq** * **threshold** future kwargs (to be implemented): cut_after_every, extend_printable_area, resize (in (none', 'inner', 'outer')) """ label_specs = label_type_specs[label] dots_printable = label_specs['dots_printable'] right_margin_dots = label_specs['right_margin_dots'] right_margin_dots += right_margin_addition.get(qlr.model, 0) device_pixel_width = qlr.get_pixel_width() cut = kwargs.get('cut', True) dither = kwargs.get('dither', False) compress = kwargs.get('compress', False) red = kwargs.get('red', False) rotate = kwargs.get('rotate', 'auto') if rotate != 'auto': rotate = int(rotate) dpi_600 = kwargs.get('dpi_600', False) hq = kwargs.get('hq', True) threshold = kwargs.get('threshold', 70) threshold = 100.0 - threshold threshold = min(255, max(0, int(threshold/100.0 * 255))) if red and not qlr.two_color_support: raise BrotherQLUnsupportedCmd('Printing in red is not supported with the selected model.') try: qlr.add_switch_mode() except BrotherQLUnsupportedCmd: pass qlr.add_invalidate() qlr.add_initialize() try: qlr.add_switch_mode() except BrotherQLUnsupportedCmd: pass for image in images: if isinstance(image, Image.Image): im = image else: try: im = except: raise NotImplementedError("The image argument needs to be an Image() instance, the filename to an image, or a file handle.") if im.mode.endswith('A'): # place in front of white background and get red of transparency bg ="RGB", im.size, (255,255,255)) bg.paste(im, im.split()[-1]) im = bg elif im.mode == "P": # Convert GIF ("P") to RGB im = im.convert("RGB" if red else "L") elif im.mode == "L" and red: # Convert greyscale to RGB if printing on black/red tape im = im.convert("RGB") if dpi_600: dots_expected = [el*2 for el in dots_printable] else: dots_expected = dots_printable if label_specs['kind'] == ENDLESS_LABEL: if rotate not in ('auto', 0): im = im.rotate(rotate, expand=True) if dpi_600: im = im.resize((im.size[0]//2, im.size[1])) if im.size[0] != dots_printable[0]: hsize = int((dots_printable[0] / im.size[0]) * im.size[1]) im = im.resize((dots_printable[0], hsize), Image.ANTIALIAS) logger.warning('Need to resize the image...') if im.size[0] < device_pixel_width: new_im =, (device_pixel_width, im.size[1]), (255,)*len(im.mode)) new_im.paste(im, (device_pixel_width-im.size[0]-right_margin_dots, 0)) im = new_im elif label_specs['kind'] in (DIE_CUT_LABEL, ROUND_DIE_CUT_LABEL): if rotate == 'auto': if im.size[0] == dots_expected[1] and im.size[1] == dots_expected[0]: im = im.rotate(90, expand=True) elif rotate != 0: im = im.rotate(rotate, expand=True) if im.size[0] != dots_expected[0] or im.size[1] != dots_expected[1]: raise ValueError("Bad image dimensions: %s. Expecting: %s." % (im.size, dots_expected)) if dpi_600: im = im.resize((im.size[0]//2, im.size[1])) new_im =, (device_pixel_width, dots_expected[1]), (255,)*len(im.mode)) new_im.paste(im, (device_pixel_width-im.size[0]-right_margin_dots, 0)) im = new_im if red: filter_h = lambda h: 255 if (h < 40 or h > 210) else 0 filter_s = lambda s: 255 if s > 100 else 0 filter_v = lambda v: 255 if v > 80 else 0 red_im = filtered_hsv(im, filter_h, filter_s, filter_v) red_im = red_im.convert("L") red_im = PIL.ImageOps.invert(red_im) red_im = red_im.point(lambda x: 0 if x < threshold else 255, mode="1") filter_h = lambda h: 255 filter_s = lambda s: 255 filter_v = lambda v: 255 if v < 80 else 0 black_im = filtered_hsv(im, filter_h, filter_s, filter_v) black_im = black_im.convert("L") black_im = PIL.ImageOps.invert(black_im) black_im = black_im.point(lambda x: 0 if x < threshold else 255, mode="1") black_im = PIL.ImageChops.subtract(black_im, red_im) else: im = im.convert("L") im = PIL.ImageOps.invert(im) if dither: im = im.convert("1", dither=Image.FLOYDSTEINBERG) else: im = im.point(lambda x: 0 if x < threshold else 255, mode="1") qlr.add_status_information() tape_size = label_specs['tape_size'] if label_specs['kind'] in (DIE_CUT_LABEL, ROUND_DIE_CUT_LABEL): qlr.mtype = 0x0B qlr.mwidth = tape_size[0] qlr.mlength = tape_size[1] else: qlr.mtype = 0x0A qlr.mwidth = tape_size[0] qlr.mlength = 0 qlr.pquality = int(hq) qlr.add_media_and_quality(im.size[1]) try: if cut: qlr.add_autocut(True) qlr.add_cut_every(1) except BrotherQLUnsupportedCmd: pass try: qlr.dpi_600 = dpi_600 qlr.cut_at_end = cut qlr.two_color_printing = True if red else False qlr.add_expanded_mode() except BrotherQLUnsupportedCmd: pass qlr.add_margins(label_specs['feed_margin']) try: if compress: qlr.add_compression(True) except BrotherQLUnsupportedCmd: pass if red: qlr.add_raster_data(black_im, red_im) else: qlr.add_raster_data(im) qlr.add_print() return