Summary

This is a tool that helps dissect the information in CGM vector graphics files.

Usage

This can be used programmatically for more advanced uses, or for basic printing of the elements of a CGM file there is a command line tool provided:

$ parse_cgm <file>

Or to print only the metadata/application data (i.e. non-graphics) parts of a cgm file:

$ parse_cgm -m <file>

CGM standard

The CGM standard can be downloaded for free from from iso.org. Search for ISO/IEC 8632 on the publicly available standards page: https://standards.iso.org/ittf/PubliclyAvailableStandards/index.html.

CGM standard utility

There is a utility script that was used to extract information about the CGM standard. This shouldn't be needed anymore but is here so I don't lose it and then need to re-scrape information from the CGM standard again.

./utils/make_cgm_types.py docs/c032380e.pdf cgm/types/parsed_types.py

This script requires installing tabula-py. The makefile target scrape-standard automatically creates and uses a virtualenv to install tabula and run the script.

However the data scraped from the docs/c032380e.pdf PDF seems to be missing the EDGE_WIDTH element in one of the tables so the following element was patched in after running the script:

diff --git a/cgm/types/parsed_types.py b/cgm/types/parsed_types.py
index bff3e20..1482b42 100644
--- a/cgm/types/parsed_types.py
+++ b/cgm/types/parsed_types.py
@@ -1712,6 +1712,14 @@
     "len": "BIX",
     "range": "IXR"
   },
+  # 28 was manually added because the PDF is missing it?
+  28: {
+    "element": "EDGE_WIDTH",
+    "id": 28,
+    "type": "SS",
+    "len": "BSS",
+    "range": "SSR"
+  },
   29: {
     "element": "EDGE_COLOUR",
     "id": 29,