AprilTag-imgs

Images of all tags from all the pre-generated AprilTag 3 families. You can generate your own layouts or images of tags using our other repo, AprilTag-generation.

If the format of the markers is very small (ex : by default, 9x9 pixels), you'll need to rescale them. To do so, you may use the following imagemagick command (Unix) :

convert <small_marker>.png -scale <scale_chosen_in_percent>% <big_marker>.png

Alternately, you can use the supplied native Python 3 script tag_to_svg.py to create a SVG (Scalable Vector Graphics) Version of a tag. For example:

python3 tag_to_svg.py tagStandard52h13/tag52_13_00007.png tag52_13_00007.svg --size=20mm

Batched AprilTag Bundles Generation

You can also use the script tag_to_bundle_svg.py to create batch of bundle of tags. For example:

python3 tag_to_bundle_svg.py \
    --tag_folder=tagStandard41h12 --tag_prefix=tag41_12_ \
    --out_folder=outputs --num_bundles=20 \
    --size=90mm --num_tile=2 --stride=0

This script will generate 20 svg files and a description in json in outputs folder. Each svg file contains 4 tags (2x2) with a size of 90mm. The description file matches the one used by apriltag_ros, which is defined in apriltag_ros/config /tags.yaml.

To Build A Large Marker

The following command generate a 11 by 11 grid of tags. With the individual_print flag, each tag is exported individually and one obtains 61 svg file.

python3 tag_to_bundle_svg.py --tag_folder=tagStandard41h12  --out_folder=outputs --num_bundles=1 --size=180mm --num_tile=11 --stride=1 --margin=1 --individual_print=true

After obtaining the svg files, you can use inkscape to convert them into pdf. Using the solution from Johannski, put all svg files in a folder and create a batch file (e.g. convert.bat) with the following content:

@Echo off

set count=0
set validInput1=svg
set validInput2=pdf
set validInput3=eps
set validOutput1=eps
set validOutput2=pdf
set validOutput3=png

echo This script allows you to convert all files in this folder from one file type to another.

set valid=0
echo Allowed file types for source: %validInput1%, %validInput2%, %validInput3%

:whileInNotCorrect
    set /p sourceType=What file type do you want to use as a source?
    if "%sourceType%" EQU "%validInput1%" set valid=1
   if "%sourceType%" EQU "%validInput2%" set valid=1
   if "%sourceType%" EQU "%validInput3%" set valid=1
   if %valid% EQU 0 (
        echo Invalid input! Please use one of the following: %validInput1%, %validInput2%, %validInput3%
      goto :whileInNotCorrect
      )

set valid=0
echo Allowed file types for output: %validOutput1%, %validOutput2%, %validOutput3%      
:whileOutNotCorrect
    set /p outputType=What file type do you want to convert to?
    if "%outputType%" EQU "%validOutput1%" set valid=1
   if "%outputType%" EQU "%validOutput2%" set valid=1
   if "%outputType%" EQU "%validOutput3%" set valid=1
   if %valid% EQU 0 (
        echo Invalid input! Please use one of the following: %validOutput1%, %validOutput2%, %validOutput3%   
      goto :whileOutNotCorrect
      )
      
set /p dpi=With what dpi should it be exported (e.g. 300)?

for %%i in (.\*.%sourceType%) do (
   echo %%i.%outputType%
   inkscape %%i --export-type=%outputType% --export-filename=%%i.%outputType% --export-dpi=%dpi%
   )
   
pause

Note that this script requires Inkscape to be installed and added to the path. After obtaining pdf files, you can combine them into a single pdf file using pdf tools.

sciyen/apriltag-imgs

AprilTag-imgs

Batched AprilTag Bundles Generation

To Build A Large Marker