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REL Converter
Need REL files in a different format? reaConverter batch converts to JPG, PNG, PDF, TIFF and more.
How to Convert .rel Files in Bulk
1. Install reaConverter
2. Select REL Files
3. Start Conversion
Step by step
See It in Action
For quick and effortless REL file handling on your PC, reaConverter offers powerful conversion tools with batch processing. Best of all, it works entirely offline — ensuring your sensitive data never leaves your computer.
GIS Toolkit
Do more with your GIS data
Need REL data as something anyone can open? reaConverter renders imagery and elevation grids into standard images and documents without QGIS or ArcGIS, and works through whole folders in one pass.
- Render imagery, elevation grids and scanned charts to TIFF, PNG, JPG or PDF
- Resize, crop and set DPI on the output in the same run
- Bring tiles, scenes and grids from many sources into one consistent format
- Convert incoming survey and field data automatically with Watch Folders
- Script GIS conversions from the command line for pipelines and scheduled jobs
- Keep cadastral, utility and client data on your PC: nothing is uploaded
User reviews
From those who tried it
Average User Rating:Last updated on July 28, 2026
Questions & Answers
REL files: Frequently Asked Questions
What are REL files?
REL (MiraMon Raster Images) is a plain-text description file in the style of Windows INI files, with sections and keys, that controls how a set of raster files is interpreted. The raw pixels live in one or more .img files, and the .rel file, usually named with an I at the end, holds the number of rows and columns, the data type, the band names, the compression of each band, the georeferencing, the default colors, and metadata such as the origin, quality, sensor, and units of the data. A multiband image is made of several value files and a single .rel file, an arrangement supported since MiraMon version 4.0, and the value files may also be JPEG or JPEG 2000. The .img data come in 13 subformats, from 1-bit masks and 8-bit categories to integers and real numbers, and most of them can be compressed with run-length encoding and indexed for faster access. Older datasets used a .doc file instead of .rel, with fewer details. To convert such a raster to graphics, a program reads the .rel file first, decodes each band, applies the stated symbolization, and paints the picture. Masks become black and white, 8-bit data becomes grayscale or a palette, real numbers are scaled, and three bands can be combined into an RGB picture. The result can be saved as PNG, JPEG, TIFF, or GeoTIFF. The .img file and the .rel file must stay together. Supported by MiraMon.
Can reaConverter open REL files?
reaConverter fully supports the REL file format – open, edit, and export REL files to any other popular file format with ease.
Do I need QGIS or ArcGIS to convert REL files?
No. reaConverter reads REL files on its own, so the conversion needs no GIS installation and no licence. It handles whole folders at once, which suits survey archives, tile sets and data deliveries that have to reach people working in other software.
How do I change REL to another format?
reaConverter is a user-friendly tool for converting REL files. Once installed on your computer, it allows you to convert all your .rel files at once with just a few clicks. You can even convert rel images directly from Windows Explorer using the right-click menu — fast and convenient.
Why choose offline conversion with reaConverter?
Keep your sensitive data 100% private with offline processing that never exposes files to cloud risks. Our software meets strict compliance standards (GDPR, HIPAA, CCPA) while handling confidential documents for legal, healthcare and financial sectors.
Can I convert REL online?
If you only want to convert a few REL files, you are welcome to try our free online REL converter.
How can I turn REL files on my computer to another format?
The best way to convert REL files on your PC is to get a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch files conversions, including conversion from REL.
How can I automate REL files conversion?
reaConverter supports all the essential automation features, such as right-click сonversion and Watch Folders, for the most efficient automated file conversion in any software of its kind.
Can I convert REL files using scripts or the command-line interface?
reaConverter provides full access to all its features from the Windows command-line shell, including the command-line rel converter.
What else can I do with reaConverter?
Convert microscopy filesResize picturesConvert PDFAdd watermark on photoConvert GIS files
What formats can I convert a REL file to?
Discover More
Beyond REL conversion
Convert .rel files in batches of any size, with editing and processing applied along the way. The same tool also handles 800+ other formats, including CAD, medical imaging, and GIS.
