RLC to TXT Converter

RLC to TXT Conversion Explained

Converting .RLC (Run-Length Coding) files to .TXT (Plain Text) changes a 1-bit raster image into raw, editable text characters. Because .RLC files are scanned images—often used for legacy CAD drawings, maps, and technical documents—this conversion requires Optical Character Recognition (OCR) to identify letters and numbers within the pixels.

People convert .RLC to .TXT to extract written data, such as material lists, engineering notes, or title block information, without manually retyping it. You gain searchable, lightweight text data that opens on any device. However, you lose all graphical elements, including lines, shapes, spatial layout, and signatures. If you need to preserve the actual drawing or map, converting to .TXT is a bad idea. You should convert to .PDF or .TIFF for archiving, or use raster-to-vector software to create a .DXF file.

Typical Tasks and Users

This conversion is highly specific and primarily serves professionals dealing with legacy document digitization.

• CAD Drafters and Engineers: Extracting Bill of Materials (BOM) tables or specification notes from old scanned blueprints to paste into modern CAD software.
• Archivists and Data Entry Clerks: Digitizing text from scanned historical maps or technical manuals to make the content searchable in a database.
• GIS Technicians: Pulling coordinate labels or parcel numbers from legacy 1-bit raster maps into a text file for batch processing.

Software & Tool Support

Handling .RLC files usually requires specialized imaging or CAD software, while .TXT files are universally supported.

• Viewing RLC files: You can open .RLC images using IrfanView (with the formats plugin), XnView, or Autodesk AutoCAD equipped with the Raster Design toolset.
• OCR and Conversion: Command-line tools like Tesseract OCR can extract text if the .RLC is first converted to a standard image format like TIFF. Commercial software like ABBYY FineReader can also process high-contrast technical scans.
• Editing TXT files: Once converted, the text can be edited in Notepad++, Microsoft Notepad, Apple TextEdit, or any programming IDE.

Pros and Cons of the Conversion

Pros:

• Searchability: Text locked inside a scanned drawing becomes fully searchable.
• Editability: You can easily copy, modify, and format the extracted text.
• File Size: A .TXT file containing extracted notes is drastically smaller than a high-resolution .RLC raster image.
• Universal Compatibility: Plain text requires no specialized CAD or imaging software to open.

Cons:

• Total Graphic Loss: All geometry, hatching, borders, and visual context are permanently discarded.
• OCR Errors: Technical drawings often feature text intersecting with lines or using non-standard architectural fonts, leading to misread characters.
• Layout Destruction: Plain text does not retain the spatial positioning of labels on a map or drawing.

Conversion Difficulties & Why Convert.Guru

The technical pipeline to convert .RLC to .TXT is complex. The system must first decode the run-length compression to render the 1-bit raster image. Next, it must apply noise reduction to clean up scan artifacts (like speckles or skewed pages). Finally, an OCR engine must scan the pixels, separate text from CAD geometry, and map recognized shapes to Unicode characters. Standard OCR tools often fail here because they cannot distinguish a straight line from the letter "I" or "l" in a dense technical drawing.

Convert.Guru handles this pipeline automatically. It natively decodes the .RLC format, applies necessary image pre-processing, and utilizes advanced OCR to extract text as accurately as possible. It eliminates the need to string together multiple command-line utilities or buy expensive CAD raster plugins just to extract a few paragraphs of text.

RLC vs. TXT: What is the better choice?

Which format should you choose?

Choose .RLC if you are archiving legacy technical drawings and need to preserve the exact visual state of the scanned document, including all lines, stamps, and handwritten signatures.

Choose .TXT only when your goal is data extraction. It is the right choice if you need to pull written specifications, tables, or labels out of an image to use in a database, spreadsheet, or word processor.

Avoid this conversion if you want to edit the drawing itself. If you need editable lines and shapes, you must use raster-to-vector conversion to change the .RLC into a .DXF or .DWG file.

Conclusion

Converting .RLC to .TXT makes sense exclusively for extracting written data from legacy scanned CAD drawings and maps using OCR. The biggest limitation to watch for is the complete loss of all graphical elements and spatial layout, alongside potential character recognition errors caused by intersecting CAD lines. Convert.Guru provides a reliable, browser-based solution for this exact conversion, handling the complex raster decoding and OCR extraction in one seamless step without requiring expensive desktop software.