Basic Data Matrix 2D Barcode — plotnine

A Data Matrix 2D barcode visualization that encodes data into a compact square or rectangular matrix of black and white cells. Data Matrix codes follow the ISO/IEC 16022 standard, featuring an L-shaped finder pattern (solid borders on two adjacent sides) and alternating timing patterns on the opposite sides. This barcode format is ideal for marking small items and supports high data density with built-in error correction (ECC 200).

Basic Data Matrix 2D Barcode rendered with plotnine

Python source (plotnine)

""" anyplot.ai
datamatrix-basic: Basic Data Matrix 2D Barcode
Library: plotnine 0.15.4 | Python 3.13.13
Quality: 85/100 | Updated: 2026-05-20
"""

import os
import sys


# Work around filename shadowing the plotnine library
sys.path.pop(0)
import numpy as np
import pandas as pd
from plotnine import (
    aes,
    coord_fixed,
    element_rect,
    element_text,
    geom_tile,
    ggplot,
    labs,
    scale_fill_manual,
    theme,
    theme_void,
)


# Theme tokens
THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"

# Data - Create a 16x16 Data Matrix barcode encoding "SERIAL:12345678"
np.random.seed(42)

size = 16

# Initialize matrix (0 = white, 1 = black)
dm_matrix = np.zeros((size, size), dtype=int)

# L-shaped finder pattern: solid black left edge and bottom edge
dm_matrix[:, 0] = 1
dm_matrix[size - 1, :] = 1

# Alternating clock pattern on top and right edges
for i in range(size):
    dm_matrix[0, i] = i % 2
for i in range(size):
    dm_matrix[i, size - 1] = (size - 1 - i) % 2

# Data encoding area simulating "SERIAL:12345678"
content = "SERIAL:12345678"
data_values = [ord(c) for c in content]
data_idx = 0
for row in range(1, size - 1):
    for col in range(1, size - 1):
        val = data_values[data_idx % len(data_values)]
        bit_pos = (row + col) % 8
        dm_matrix[row, col] = (val >> bit_pos) & 1
        data_idx += 1

# Quiet zone (2-module white border for scanning reliability)
quiet_zone = 2
padded_size = size + 2 * quiet_zone
dm_with_border = np.zeros((padded_size, padded_size), dtype=int)
dm_with_border[quiet_zone : quiet_zone + size, quiet_zone : quiet_zone + size] = dm_matrix

# Convert matrix to DataFrame (flip y so origin is bottom-left)
rows = []
for row in range(padded_size):
    for col in range(padded_size):
        rows.append({"x": col, "y": padded_size - 1 - row, "value": str(dm_with_border[row, col])})

df = pd.DataFrame(rows)

# Plot
plot = (
    ggplot(df, aes(x="x", y="y", fill="value"))
    + geom_tile(color=None, size=0)
    + scale_fill_manual(values={"0": "#FFFFFF", "1": "#000000"})
    + coord_fixed()
    + labs(
        title="datamatrix-basic · python · plotnine · anyplot.ai",
        subtitle="16×16 ECC 200 symbol · 25% error correction",
        caption="Encoded: SERIAL:12345678",
    )
    + theme_void()
    + theme(
        figure_size=(6, 6),
        plot_title=element_text(size=12, weight="bold", ha="center", color=INK),
        plot_subtitle=element_text(size=9, ha="center", color=INK_SOFT),
        plot_caption=element_text(size=9, ha="right", color=INK_SOFT),
        panel_background=element_rect(fill=PAGE_BG),
        plot_background=element_rect(fill=PAGE_BG),
        legend_position="none",
    )
)

# Save
plot.save(f"plot-{THEME}.png", dpi=400, width=6, height=6, units="in")

Part of Basic Data Matrix 2D Barcode on anyplot.ai.

Basic Data Matrix 2D Barcode — plotnine

Python source (plotnine)

Other implementations