CGM to TXT Converter

CGM to TXT Conversion Explained

Converting a .CGM (Computer Graphics Metafile) to a .TXT (Plain Text) file is a data extraction process rather than a visual conversion. .CGM is an ISO standard 2D vector graphics format used heavily in technical illustration and engineering. .TXT is a raw text format containing no graphical data.

When you convert .CGM to .TXT, you discard all lines, polygons, colors, and raster images. The output retains only the embedded text strings, such as labels, part numbers, and annotations. Alternatively, if the .CGM uses the "Clear Text" encoding profile, the conversion might expose the raw, human-readable code instructions used to draw the graphic. This conversion is highly specialized and is a bad idea if you need to retain the visual drawing.

Typical Tasks and Users

This conversion is primarily used by professionals in aerospace, defense, and manufacturing who work with technical documentation standards like S1000D or ATA iSpec 2200.

• Technical Writers and Translators: Extracting text labels from technical illustrations to translate them into different languages without manually retyping them.
• Data Analysts: Pulling part numbers, callouts, or Bill of Materials (BOM) data directly from engineering drawings to populate databases.
• Archivists: Converting the text content of legacy technical drawings into searchable text files for indexing in a document management system.

Software & Tool Support

Because .CGM is a niche format, standard consumer image editors cannot parse it. You need specialized software to open, edit, or extract data from these files.

• Larson Software Technology: Offers enterprise-grade CGM viewing and conversion tools specifically built for aerospace and defense workflows.
• SDI (System Development Inc.): Provides professional CGM editors and command-line utilities that can parse and extract text from complex metafile structures.
• CorelDRAW: A commercial vector graphics editor that can import .CGM files, allowing users to manually select and copy text elements.
• Command-Line Tools: Utilities like strings on Linux/macOS can extract readable text from binary .CGM files, though the output is often messy and unformatted.
• Notepad++: Can be used to open and read .CGM files that are saved using the "Clear Text" encoding method, though it cannot parse binary .CGM files.

Pros and Cons of the Conversion

Pros:

• Text Accessibility: Unlocks embedded text for search engines, databases, and translation memory software.
• File Size: .TXT files are exceptionally small, often reducing file size by over 99% compared to the original graphic.
• Universal Compatibility: Plain text can be opened on any operating system without specialized CAD or illustration software.

Cons:

• Total Visual Loss: All geometry, lines, shapes, and raster elements are permanently deleted.
• Loss of Spatial Context: The extracted text loses its coordinates. You will not know which part number points to which component.
• Formatting Loss: Font types, sizes, colors, and text alignment are completely discarded.

Conversion Difficulties & Why Convert.Guru

Extracting text from a .CGM file is technically difficult due to the format's complex specifications (ISO/IEC 8632). .CGM files can be encoded in three ways: Binary, Character, or Clear Text. Parsing a Binary .CGM requires reading specific opcodes to separate text strings from drawing commands. Furthermore, if the original software exported the text as "stroked" (converted into vector paths and polygons rather than actual font characters), text extraction is impossible without Optical Character Recognition (OCR).

Convert.Guru handles these technical hurdles efficiently. It automatically detects the .CGM encoding profile, parses the metafile structure, and cleanly extracts the embedded text strings. This saves users from buying expensive aerospace illustration software just to retrieve a few part numbers or labels.

CGM vs. TXT: What is the better choice?

Which format should you choose?

Choose .CGM if you are storing, editing, or sharing technical illustrations, CAD exports, or aerospace diagrams. It is the mandatory standard for many defense and aviation manuals.

Choose .TXT only if your sole objective is to analyze, index, or translate the text hidden inside the drawing.

Avoid this conversion if you want to view the graphic on the web or share it with non-technical users. If you need a universally readable image format, convert .CGM to .SVG (for vector editing) or .PDF (for document sharing) instead.

Conclusion

Converting .CGM to .TXT is a highly specific data extraction process designed for indexing, translation, and parts management. It makes sense only when the text data is more valuable than the technical drawing itself. The biggest limitation is the complete destruction of all visual and spatial information, meaning the extracted text will lack context. For users who need to pull text from technical metafiles quickly and accurately without deploying enterprise CAD software, Convert.Guru provides a reliable, automated solution for this exact conversion.