OpenCV pattern generation tool

Lifted mainly from opencv/doc/pattern_tools. A really simple way to generate some patterns.

Added some extra utilities like YAML files, loading from YAML files etc

Installation

pip install opencv-pattern

Usage

usage: pattern [-H] [--from_config FROM_CONFIG] [-o OUTPUT] [-c COLUMNS] [-r ROWS] [-T {circles,acircles,checkerboard,radon_checkerboard,charuco_board}]
               [-u {mm,inches,px,m}] [-s SQUARE_SIZE] [-R RADIUS_RATE] [-w PAGE_WIDTH] [-h PAGE_HEIGHT] [-a {A0,A1,A2,A3,A4,A5}]
               [-m MARKERS [MARKERS ...]] [-p ARUCO_MARKER_SIZE] [-f DICT_FILE]

generate camera-calibration pattern

options:
  -H, --help            show help
  --from_config FROM_CONFIG
                        generate pattern from config
  -o OUTPUT, --output OUTPUT
                        output file
  -c COLUMNS, --columns COLUMNS
                        pattern columns
  -r ROWS, --rows ROWS  pattern rows
  -T {circles,acircles,checkerboard,radon_checkerboard,charuco_board}, --type {circles,acircles,checkerboard,radon_checkerboard,charuco_board}
                        type of pattern
  -u {mm,inches,px,m}, --units {mm,inches,px,m}
                        length unit
  -s SQUARE_SIZE, --square_size SQUARE_SIZE
                        size of squares in pattern
  -R RADIUS_RATE, --radius_rate RADIUS_RATE
                        circles_radius = square_size/radius_rate
  -w PAGE_WIDTH, --page_width PAGE_WIDTH
                        page width in units
  -h PAGE_HEIGHT, --page_height PAGE_HEIGHT
                        page height in units
  -a {A0,A1,A2,A3,A4,A5}, --page_size {A0,A1,A2,A3,A4,A5}
                        page size, superseded if -h and -w are set
  -m MARKERS [MARKERS ...], --markers MARKERS [MARKERS ...]
                        list of cells with markers for the radon checkerboard. Marker coordinates as list of numbers: -m 1 2 3 4 means markers in cells
                        [1, 2] and [3, 4]
  -p ARUCO_MARKER_SIZE, --marker_size ARUCO_MARKER_SIZE
                        aruco markers size for ChAruco pattern (default 10.0)
  -f DICT_FILE, --dict_file DICT_FILE
                        file name of custom aruco dictionary for ChAruco pattern

Config

Generates a pattern with the config.

pattern --from_config /path/to/config

Checkerboard

pattern -T checkerboard -s 5 -u mm --output checkerboard.svg

columns: 8
from_config: null
output: checkerboard.svg
p_type: checkerboard
page_size: A4
radius_rate: 5.0
rows: 11
square_size: 5.0
units: mm

Circles

pattern -T circles -s 5 -u mm --output circles.svg

columns: 8
from_config: null
output: circles.svg
p_type: circles
page_size: A4
radius_rate: 5.0
rows: 11
square_size: 5.0
units: mm

Acircles

pattern -T acircles -s 5 -u mm --output acircles.svg

columns: 8
from_config: null
output: acircles.svg
p_type: acircles
page_size: A4
radius_rate: 5.0
rows: 11
square_size: 5.0
units: mm

Radon checkerboard

pattern -T radon_checkerboard -s 5 -u mm --output radon_checkerboard.svg

columns: 8
from_config: null
output: radon_checkerboard.svg
p_type: radon_checkerboard
page_size: A4
radius_rate: 5.0
rows: 11
square_size: 5.0
units: mm

Charuco board

pattern -T charuco_board --dict_file DICT_ARUCO_ORIGINAL.json.gz --output charuco_board.svg

You can either choose one of:

• DICT_4X4_50.json.gz
• DICT_4X4_100.json.gz
• DICT_4X4_250.json.gz
• DICT_4X4_1000.json.gz
• DICT_5X5_50.json.gz
• DICT_5X5_100.json.gz
• DICT_5X5_250.json.gz
• DICT_5X5_1000.json.gz
• DICT_6X6_50.json.gz
• DICT_6X6_100.json.gz
• DICT_6X6_250.json.gz
• DICT_6X6_1000.json.gz
• DICT_7X7_50.json.gz
• DICT_7X7_100.json.gz
• DICT_7X7_250.json.gz
• DICT_7X7_1000.json.gz
• DICT_APRILTAG_16h5.json.gz
• DICT_APRILTAG_25h9.json.gz
• DICT_APRILTAG_36h10.json.gz
• DICT_APRILTAG_36h11.json.gz
• DICT_ARUCO_ORIGINAL.json.gz

or your own personal dict file.

aruco_marker_size: 10.0
columns: 8
dict_file: DICT_ARUCO_ORIGINAL.json.gz
from_config: null
output: charuco_board.svg
p_type: charuco_board
page_size: A4
radius_rate: 5.0
rows: 11
square_size: 20.0
units: mm

API

Example of how to run in the API:

# example_checkerboard.py
from opencv_pattern.gen_pattern import PatternMaker

"""
Checkerboard example"""
# Parameters (same as CLI args)
cols = 8
rows = 11
output = "checkerboard.svg"
units = "mm"
square_size = 5.0
radius_rate = 5.0
page_width = 210   # A4 width in mm
page_height = 297  # A4 height in mm
markers = None
aruco_marker_size = 10.0
dict_file = "DICT_ARUCO_ORIGINAL.json"  # not used for checkerboard

# Create the pattern maker
pm = PatternMaker(
    cols, rows, output, units,
    square_size, radius_rate,
    page_width, page_height,
    markers, aruco_marker_size, dict_file
)

# Generate checkerboard
pm.make_checkerboard_pattern()

# Save result
pm.save()
print(f"Checkerboard saved to {output}")


"""
Charuco board example
"""
# Parameters
cols = 8
rows = 11
output = "charuco_board.svg"
units = "mm"
square_size = 20.0      # must be larger than aruco_marker_size
radius_rate = 5.0
page_width = 210        # A4
page_height = 297
markers = None
aruco_marker_size = 10.0
dict_file = "DICT_4X4_1000.json.gz"  # bundled in the package

# Create the pattern maker
pm = PatternMaker(
    cols, rows, output, units,
    square_size, radius_rate,
    page_width, page_height,
    markers, aruco_marker_size, dict_file
)

# Generate ChArUco board
pm.make_charuco_board()

# Save result
pm.save()
print(f"ChArUco board saved to {output}")