visualize_annotations.py
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[Usage]: python3 visualize_annotations.py <image_dir> <math_dir> <output_dir> <char_dir>

"visualize_annotations.py": visualize math regions and character regions on images. 

(Character regions path is optional. If character regions are not given as input, then only math regions are visualized on document images.)

This script takes 3 or 4 parameters.
<image_dir>: directory path containing 600 DPI images.
<math_dir>: directory path containing annotations for math regions (".math files")
<output_dir>: directory path to store rendered images for corresponding PDF files.
<char_dir>: directory path containing annotations for character regions (".char files")

<char_dir> is optional parameter. 
<math_dir> is optional to make char visualization possible on test set which does not have math annotations.
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