parkerlreed · July 9, 2025 18:53 · seanritner · Jul 9, 2025 · parkerlreed · Jul 9, 2025
diff --git a/ctp500_print.py b/ctp500_print.py
 import sys
 import bluetooth
 from PIL import Image
 import numpy as np

 def convert_image_to_escpos_raster(filepath, width=384, dither=False):
    # Load RGBA image and separate alpha mask
    img_rgba = Image.open(filepath).convert("RGBA")
    alpha = img_rgba.getchannel("A")

    # Flatten onto white background
    white_bg = Image.new("RGBA", img_rgba.size, (255, 255, 255, 255))
    flattened = Image.alpha_composite(white_bg, img_rgba).convert("L")

    # Resize both image and alpha mask
    height = int(flattened.height * (width / flattened.width))
    img_resized = flattened.resize((width, height), Image.Resampling.LANCZOS)
    alpha_resized = alpha.resize((width, height), Image.Resampling.LANCZOS)

    # Convert alpha to numpy for masking
    alpha_mask = np.array(alpha_resized, dtype=np.uint8)
    img_array = np.array(img_resized, dtype=np.uint8)

    # Apply alpha mask BEFORE dithering - set transparent areas to white
    img_array[alpha_mask < 128] = 255

    # Convert back to PIL Image for dithering/thresholding
    img_masked = Image.fromarray(img_array, mode="L")

    # Apply dither or threshold
    if dither:
        from PIL.Image import Dither
        img_bw = img_masked.convert("1", dither=Dither.FLOYDSTEINBERG)
    else:
        img_bw = img_masked.point(lambda x: 0 if x < 128 else 255, mode="1")

    # Convert to NumPy for final processing
    bits = np.array(img_bw, dtype=np.uint8)

    # Invert bits for ESC/POS format (0=black, 1=white)
    # PIL's mode "1" gives us 0=black, 255=white
    # But we need 0=white, 1=black for packbits
    bits_inverted = (bits == 0).astype(np.uint8)

    # Pack bits into bytes for raster format
    packed = np.packbits(bits_inverted, axis=1)
    raster_data = packed.tobytes()

    # ESC/POS header
    width_bytes = (img_bw.width + 7) // 8
    xL = width_bytes & 0xFF
    xH = (width_bytes >> 8) & 0xFF
    yL = img_bw.height & 0xFF
    yH = (img_bw.height >> 8) & 0xFF
    header = b'\x1D\x76\x30\x00' + bytes([xL, xH, yL, yH])

    return header + raster_data

 def build_command_stream(image_bytes):
    return (
        b'\x1D\x67\x39'
        b'\x1E\x47\x03'
        b'\x1D\x67\x69'
        b'\x1B\x40'
        b'\x1D\x49\xF0\x19'
        + image_bytes +
        b'\n\n\n\x1D\x56\x00'
    )

 def main():
    if len(sys.argv) < 3:
        print("Usage: print_image_final_clean_mask.py <image.png> <MAC_ADDRESS> [--dither]")
        sys.exit(1)

    image_path = sys.argv[1]
    mac = sys.argv[2]
    dither = "--dither" in sys.argv

    print("Converting image...")
    img_data = convert_image_to_escpos_raster(image_path, dither=dither)
    payload = build_command_stream(img_data)

    print(f"Connecting to {mac}...")
    sock = bluetooth.BluetoothSocket(bluetooth.RFCOMM)
    sock.connect((mac, 1))
    print("Sending...")
    sock.send(payload)
    sock.close()
    print("Done.")

 if __name__ == "__main__":
    main()
	import sys
	import bluetooth
	from PIL import Image
	import numpy as np

	def convert_image_to_escpos_raster(filepath, width=384, dither=False):
	# Load RGBA image and separate alpha mask
	img_rgba = Image.open(filepath).convert("RGBA")
	alpha = img_rgba.getchannel("A")

	# Flatten onto white background
	white_bg = Image.new("RGBA", img_rgba.size, (255, 255, 255, 255))
	flattened = Image.alpha_composite(white_bg, img_rgba).convert("L")

	# Resize both image and alpha mask
	height = int(flattened.height * (width / flattened.width))
	img_resized = flattened.resize((width, height), Image.Resampling.LANCZOS)
	alpha_resized = alpha.resize((width, height), Image.Resampling.LANCZOS)

	# Convert alpha to numpy for masking
	alpha_mask = np.array(alpha_resized, dtype=np.uint8)
	img_array = np.array(img_resized, dtype=np.uint8)

	# Apply alpha mask BEFORE dithering - set transparent areas to white
	img_array[alpha_mask < 128] = 255

	# Convert back to PIL Image for dithering/thresholding
	img_masked = Image.fromarray(img_array, mode="L")

	# Apply dither or threshold
	if dither:
	from PIL.Image import Dither
	img_bw = img_masked.convert("1", dither=Dither.FLOYDSTEINBERG)
	else:
	img_bw = img_masked.point(lambda x: 0 if x < 128 else 255, mode="1")

	# Convert to NumPy for final processing
	bits = np.array(img_bw, dtype=np.uint8)

	# Invert bits for ESC/POS format (0=black, 1=white)
	# PIL's mode "1" gives us 0=black, 255=white
	# But we need 0=white, 1=black for packbits
	bits_inverted = (bits == 0).astype(np.uint8)

	# Pack bits into bytes for raster format
	packed = np.packbits(bits_inverted, axis=1)
	raster_data = packed.tobytes()

	# ESC/POS header
	width_bytes = (img_bw.width + 7) // 8
	xL = width_bytes & 0xFF
	xH = (width_bytes >> 8) & 0xFF
	yL = img_bw.height & 0xFF
	yH = (img_bw.height >> 8) & 0xFF
	header = b'\x1D\x76\x30\x00' + bytes([xL, xH, yL, yH])

	return header + raster_data

	def build_command_stream(image_bytes):
	return (
	b'\x1D\x67\x39'
	b'\x1E\x47\x03'
	b'\x1D\x67\x69'
	b'\x1B\x40'
	b'\x1D\x49\xF0\x19'
	+ image_bytes +
	b'\n\n\n\x1D\x56\x00'
	)

	def main():
	if len(sys.argv) < 3:
	print("Usage: print_image_final_clean_mask.py <image.png> <MAC_ADDRESS> [--dither]")
	sys.exit(1)

	image_path = sys.argv[1]
	mac = sys.argv[2]
	dither = "--dither" in sys.argv

	print("Converting image...")
	img_data = convert_image_to_escpos_raster(image_path, dither=dither)
	payload = build_command_stream(img_data)

	print(f"Connecting to {mac}...")
	sock = bluetooth.BluetoothSocket(bluetooth.RFCOMM)
	sock.connect((mac, 1))
	print("Sending...")
	sock.send(payload)
	sock.close()
	print("Done.")

	if __name__ == "__main__":
	main()