QL-800 series: printing black/red/white labels (CLI: --red)

README.md

@@ -15,7 +15,7 @@ The following printers are claimed to be supported (✓ means verified by the au
 
 * QL-500 (✓), QL-550 (✓), QL-560, QL-570 (✓), QL-580N, QL-650TD, QL-700 (✓), QL-710W (✓), QL-720NW (✓), QL-800, QL-810W, QL-820NWB (✓), QL-1050, and QL-1060N.
 
-The new QL-800 series can print labels with two colors (black and red) on DK-22251 labels. This is not yet supported by this package.
+The new QL-800 series can print labels with two colors (black and red) on DK-22251 labels.
 
 ## Why
 
@@ -63,7 +63,7 @@ giving:
 
     usage: brother_ql_create [-h] [--model MODEL] [--label-size LABEL_SIZE]
                              [--rotate {0,90,180,270}] [--threshold THRESHOLD]
-                             [--dither] [--compress] [--no-cut]
+                             [--dither] [--compress] [--red] [--no-cut]
                              [--loglevel LOGLEVEL]
                              image [outfile]
     
@@ -90,6 +90,8 @@ giving:
                             set, --threshold is meaningless.
       --compress, -c        Enable compression (if available with the model).
                             Takes more time but results in smaller file size.
+      --red                 Create a label to be printed in black/red/white (only
+                            with QL-800, QL-810W, QL-820NWB on DK-22251 labels).
       --no-cut              Don't cut the tape after printing the label.
       --loglevel LOGLEVEL   Set to DEBUG for verbose debugging output to stderr.
 

brother_ql/brother_ql_create.py

@@ -5,11 +5,12 @@ from __future__ import division
 import sys, argparse, logging
 
 from PIL import Image
-import PIL.ImageOps
+import PIL.ImageOps, PIL.ImageChops
 
 from brother_ql.raster import BrotherQLRaster
 from brother_ql.devicedependent import models, label_type_specs, ENDLESS_LABEL, DIE_CUT_LABEL, ROUND_DIE_CUT_LABEL
 from brother_ql import BrotherQLError, BrotherQLUnsupportedCmd, BrotherQLUnknownModel
+from brother_ql.image_trafos import filtered_hls
 
 try:
     stdout = sys.stdout.buffer
@@ -33,6 +34,7 @@ def main():
     parser.add_argument('--threshold', '-t', type=float, default=70.0, help='The threshold value (in percent) to discriminate between black and white pixels.')
     parser.add_argument('--dither', '-d', action='store_true', help='Enable dithering when converting the image to b/w. If set, --threshold is meaningless.')
     parser.add_argument('--compress', '-c', action='store_true', help='Enable compression (if available with the model). Takes more time but results in smaller file size.')
+    parser.add_argument('--red', action='store_true', help='Create a label to be printed in black/red/white (only with QL-800, QL-810W, QL-820NWB on DK-22251 labels).')
     parser.add_argument('--no-cut', dest='cut', action='store_false', help="Don't cut the tape after printing the label.")
     parser.add_argument('--loglevel', type=lambda x: getattr(logging, x), default=logging.WARNING, help='Set to DEBUG for verbose debugging output to stderr.')
     args = parser.parse_args()
@@ -54,11 +56,11 @@ def main():
 
     qlr.exception_on_warning = True
 
-    create_label(qlr, args.image, args.label_size, threshold=args.threshold, cut=args.cut, rotate=args.rotate, dither=args.dither, compress=args.compress)
+    create_label(qlr, args.image, args.label_size, threshold=args.threshold, cut=args.cut, rotate=args.rotate, dither=args.dither, compress=args.compress, red=args.red)
 
     args.outfile.write(qlr.data)
 
-def create_label(qlr, image, label_size, threshold=70, cut=True, dither=False, compress=False, **kwargs):
+def create_label(qlr, image, label_size, threshold=70, cut=True, dither=False, compress=False, red=False, **kwargs):
 
     label_specs = label_type_specs[label_size]
     dots_printable = label_specs['dots_printable']
@@ -101,15 +103,33 @@ def create_label(qlr, image, label_size, threshold=70, cut=True, dither=False, c
         new_im.paste(im, (device_pixel_width-im.size[0]-right_margin_dots, 0))
         im = new_im
 
-    im = im.convert("L")
+    if red:
-    im = PIL.ImageOps.invert(im)
+        filter_h = lambda h: 255 if h <  60 or h > 240 else 0
+        filter_l = lambda l: 255 if l < 220 else 0
+        filter_s = lambda s: 255 if s > 100 else 0
+        red_im = filtered_hls(im, filter_h, filter_l, filter_s)
+        red_im = red_im.convert("L")
+        red_im = PIL.ImageOps.invert(red_im)
+        red_im = red_im.convert("1", dither=Image.NONE)
 
-    if dither:
+        filter_h = lambda h: 255
-        im = im.convert("1", dither=Image.FLOYDSTEINBERG)
+        filter_l = lambda l: 255 if l < 120 else 0
+        filter_s = lambda s: 255
+        black_im = filtered_hls(im, filter_h, filter_l, filter_s)
+        black_im = black_im.convert("L")
+        black_im = PIL.ImageOps.invert(black_im)
+        black_im = black_im.convert("1", dither=Image.NONE)
+        black_im = PIL.ImageChops.subtract(black_im, red_im)
     else:
-        threshold = 100.0 - threshold
+        im = im.convert("L")
-        threshold = min(255, max(0, int(threshold/100.0 * 255))) # from percent to pixel val
+        im = PIL.ImageOps.invert(im)
-        im = im.point(lambda x: 0 if x < threshold else 255, mode="1")
+
+        if dither:
+            im = im.convert("1", dither=Image.FLOYDSTEINBERG)
+        else:
+            threshold = 100.0 - threshold
+            threshold = min(255, max(0, int(threshold/100.0 * 255))) # from percent to pixel val
+            im = im.point(lambda x: 0 if x < threshold else 255, mode="1")
 
     try:
         qlr.add_switch_mode()
@@ -142,6 +162,7 @@ def create_label(qlr, image, label_size, threshold=70, cut=True, dither=False, c
     try:
         qlr.dpi_600 = False
         qlr.cut_at_end = cut
+        qlr.two_color_printing = True if red else False
         qlr.add_expanded_mode()
     except BrotherQLUnsupportedCmd:
         pass
@@ -150,7 +171,10 @@ def create_label(qlr, image, label_size, threshold=70, cut=True, dither=False, c
         if compress: qlr.add_compression(True)
     except BrotherQLUnsupportedCmd:
         pass
-    qlr.add_raster_data(im)
+    if red:
+        qlr.add_raster_data(black_im, red_im)
+    else:
+        qlr.add_raster_data(im)
     qlr.add_print()
 
 if __name__ == "__main__":

brother_ql/image_trafos.py

@@ -0,0 +1,49 @@
+from PIL import Image
+import colorsys
+
+def HLSColor(img):
+    """ https://stackoverflow.com/a/22237709/183995 """
+    if isinstance(img,Image.Image):
+        img = img.convert('RGB')
+        r,g,b = img.split()
+        Hdat = []
+        Ldat = []
+        Sdat = []
+        for rd,gn,bl in zip(r.getdata(),g.getdata(),b.getdata()) :
+            h,l,s = colorsys.rgb_to_hls(rd/255.,gn/255.,bl/255.)
+            Hdat.append(int(h*255.))
+            Ldat.append(int(l*255.))
+            Sdat.append(int(s*255.))
+        r.putdata(Hdat)
+        g.putdata(Ldat)
+        b.putdata(Sdat)
+        return Image.merge('RGB',(r,g,b))
+    else:
+        return None
+
+def filtered_hls(im, filter_h, filter_l, filter_s, default_col=(255,255,255)):
+    hls_im = HLSColor(im)
+
+    H, L, S = 0, 1, 2
+    hls = hls_im.split()
+    mask_h = hls[H].point(filter_h)
+    mask_l = hls[L].point(filter_l)
+    mask_s = hls[S].point(filter_s)
+
+    Mdat = []
+    # for debugging:
+    #mask_h, mask_l, mask_s = hls_im.split()
+    seen = []
+    for h, l, s in zip(mask_h.getdata(), mask_l.getdata(), mask_s.getdata()):
+        if (h, l, s) not in seen:
+            seen.append((h, l, s))
+            #print((h, l, s))
+        Mdat.append(255 if (h and l and s) else 0)
+
+    mask = mask_h
+    mask.putdata(Mdat)
+
+    filtered_im = Image.new("RGB", hls_im.size, color=default_col)
+    filtered_im.paste(im, None, mask)
+    return filtered_im
+

brother_ql/raster.py

@@ -38,6 +38,7 @@ class BrotherQLRaster(object):
         self.page_number = 0
         self.cut_at_end = True
         self.dpi_600 = False
+        self.two_color_printing = False
         self._compression = False
         self.exception_on_warning = False
 
@@ -153,6 +154,7 @@ class BrotherQLRaster(object):
         flags = 0x00
         flags |= self.cut_at_end << 3
         flags |= self.dpi_600 << 6
+        flags |= self.two_color_printing << 0
         self.data += bytes([flags])
 
     def add_margins(self, dots=0x23):
@@ -174,27 +176,39 @@ class BrotherQLRaster(object):
             nbpr = number_bytes_per_row['default']
         return nbpr*8
 
-    def add_raster_data(self, image):
+    def add_raster_data(self, image, second_image=None):
         """ image: Pillow Image() """
         logger.info("raster_image_size: {0}x{1}".format(*image.size))
-        image = image.transpose(Image.FLIP_LEFT_RIGHT)
-        image = image.convert("1")
         if image.size[0] != self.get_pixel_width():
             fmt = 'Wrong pixel width: {}, expected {}'
             raise BrotherQLRasterError(fmt.format(image.size[0], self.get_pixel_width()))
-        frame = bytes(image.tobytes(encoder_name='raw'))
+        images = [image]
-        frame_len = len(frame)
+        if second_image:
-        row_len = image.size[0]//8
+            if image.size != second_image.size:
+                fmt = "First and second image don't have the same dimesions: {} vs {}."
+                raise BrotherQLRasterError(fmt.format(image.size, second_image.size))
+            images.append(second_image)
+        frames = []
+        for image in images:
+            image = image.transpose(Image.FLIP_LEFT_RIGHT)
+            image = image.convert("1")
+            frames.append(bytes(image.tobytes(encoder_name='raw')))
+        frame_len = len(frames[0])
+        row_len = images[0].size[0]//8
         start = 0
         file_str = BytesIO()
         while start + row_len <= frame_len:
-            row = frame[start:start+row_len]
+            for i, frame in enumerate(frames):
+                row = frame[start:start+row_len]
+                if second_image:
+                    file_str.write(b'\x77\x01' if i == 0 else b'\x77\x02')
+                else:
+                    file_str.write(b'\x67\x00')
+                if self._compression:
+                    row = packbits.encode(row)
+                file_str.write(bytes([len(row)]))
+                file_str.write(row)
             start += row_len
-            file_str.write(b'\x67\x00')
-            if self._compression:
-                row = packbits.encode(row)
-            file_str.write(bytes([len(row)]))
-            file_str.write(row)
         self.data += file_str.getvalue()
 
     def add_print(self, last_page=True):