.DRLE file extension
To open .DRLE files on Windows, confirm the file is DICOM-related (for example, it came from a medical imaging workflow) and do not rename it to .jpg/.png.
To open a .DRLE file, use DICOM software that supports the DICOM RLE (Lossless) transfer syntax. If your usual image viewer cannot open it, treat it as DICOM-related data and open it with DICOM tooling (for example DCMTK-based workflows).
Last updated: April 30, 2026 · Reviewed by Julian Stricker
Open on your device
Choose your operating system for a dedicated step-by-step opening guide.
How to open .DRLE files
Use these platform-specific instructions to open .DRLE files safely.
Windows
- Confirm the file is DICOM-related (for example, it came from a medical imaging workflow) and do not rename it to .jpg/.png.
- Use DICOM tooling that can handle DICOM RLE transfer syntax; in DCMTK-based environments you can use the DCMTK tool "dcmcrle" as part of a workflow to produce or work with RLE-encoded DICOM.
- If a viewer cannot open it directly, convert/transcode within a DICOM workflow to a transfer syntax your viewer supports, then open the resulting DICOM file.
Mac
- If the file came from a DICOM workflow, treat .DRLE as DICOM RLE content rather than a standard image.
- Open it using DICOM-capable tooling; if your DICOM viewer does not support this transfer syntax, transcode it within a DICOM toolchain to a supported DICOM transfer syntax and then open the output.
Linux
- Use DICOM-capable tools; DCMTK documentation shows workflows for encoding to the DICOM RLE transfer syntax using "dcmcrle" (and similar toolchains can be used to make the data compatible with other viewers).
- If your current viewer fails, transcode the DICOM to a transfer syntax it supports and then reopen the converted output.
iOS
- iOS typically will not natively preview .DRLE; transfer the file to a desktop DICOM workflow for viewing or transcoding, then view the converted DICOM in your preferred DICOM app.
Android
- Android typically will not natively open .DRLE; transfer the file to a desktop DICOM workflow for viewing or transcoding, then open the converted DICOM with a DICOM-capable app.
Security notes
- .DRLE should be treated as DICOM-related content; DICOM decoders are complex, so only open files from trusted medical systems or known sources to reduce the risk of parser vulnerabilities.
- Be cautious when receiving .DRLE via email or downloads: even if it is “just an image,” malformed DICOM/DICOM-RLE data can crash or exploit poorly maintained viewers or libraries.
- If you must share externally, consider transcoding within a controlled DICOM toolchain and validate the output in a trusted viewer before distribution.
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Can't open this file?
These are the most common causes and fixes when .DRLE files fail to open.
Common reasons
- The file opens as “unknown format” or won’t preview
- Confusion about MIME type (image/dicom-rle vs image/dicom+rle)
- Viewer opens the file but image looks wrong or fails to decode
Fix steps
- Open it with DICOM-capable tooling rather than a photo viewer.
- If your DICOM viewer does not support RLE transfer syntax, transcode within a DICOM toolchain to another DICOM transfer syntax your viewer supports, then try again.
OS-specific troubleshooting
What is a .DRLE file?
.DRLE is linked to DICOM imagery where pixel data is compressed using RLE (Run-Length Encoding) in the DICOM RLE Lossless transfer syntax (UID 1.2.840.10008.1.2.5). In practice, it represents DICOM image content encoded using the standard’s encapsulated RLE mechanism, and may appear in pipelines that explicitly map the .drle extension to a DICOM RLE media type.
Background
DICOM (Digital Imaging and Communications in Medicine) is the dominant standard for storing and transmitting medical images and related metadata. Within DICOM, pixel data can be stored uncompressed or compressed using several transfer syntaxes, including RLE Lossless, which encodes pixel runs efficiently without losing information.
The DICOM standard defines the RLE Lossless transfer syntax and how pixel data is encapsulated when compressed. Some software ecosystems and pipelines explicitly map the .drle extension to DICOM RLE content (for example, extension-to-media-type mappings used by image loading frameworks).
Because .DRLE is tied to DICOM RLE rather than consumer imaging, many default OS image apps will not recognize it. In practice, you may need DICOM tooling to view, inspect, or transcode it into a more widely supported DICOM transfer syntax for compatibility with other viewers.
Common MIME types: image/dicom-rle
Further reading
Authoritative resources for more details on the .DRLE format.
- DICOM — Wikipedia overview
- DICOM Standard Part 5: Transfer Syntax for DICOM RLE Image Compression (Section 10.4)
- DICOM Supplement 174 (PDF) — RLE transfer syntax UID and media type parameter
- DCMTK documentation: dcmcrle — Encode DICOM file to RLE transfer syntax
- Solidipes 1.3.0 docs: extension mapping for DICOM RLE (drle)
- IANA Media Types registry (reference for registered media types)
Common .DRLE issues
The file opens as “unknown format” or won’t preview
Many general image viewers do not support DICOM or the DICOM RLE Lossless transfer syntax, so the OS may not know what app to use.
- Open it with DICOM-capable tooling rather than a photo viewer.
- If your DICOM viewer does not support RLE transfer syntax, transcode within a DICOM toolchain to another DICOM transfer syntax your viewer supports, then try again.
Confusion about MIME type (image/dicom-rle vs image/dicom+rle)
Different ecosystems may label DICOM RLE differently; some mappings use "image/dicom-rle", while DICOM documentation references a media type parameter using "+rle".
- If you are integrating with a loader or pipeline, follow the mapping expected by that software (for example, an explicit mapping of .drle to a DICOM-RLE media type).
- When exchanging files, prioritize DICOM transfer syntax compatibility over the filename extension or MIME label.
Viewer opens the file but image looks wrong or fails to decode
This can happen when a tool does not fully implement the RLE encapsulation rules or expects a different transfer syntax.
- Verify the content is actually DICOM RLE Lossless (Transfer Syntax UID 1.2.840.10008.1.2.5) in your DICOM toolchain.
- Transcode the dataset to a more broadly supported DICOM transfer syntax and retry in the viewer.
FAQ
Is .DRLE the same as a normal image like JPG or PNG?
Usually no. Based on the available mappings and DICOM documentation, .DRLE is commonly associated with DICOM image data compressed using the DICOM RLE Lossless transfer syntax, which typical photo apps do not support.
Can I convert a .DRLE file by renaming it to .dcm?
Renaming only changes the extension and does not change the underlying encoding or transfer syntax. If a tool requires a specific extension, renaming might help it detect the file, but real compatibility comes from using DICOM-capable software or transcoding to a supported DICOM transfer syntax.
What DICOM feature does .DRLE relate to?
It relates to DICOM pixel data compressed with Run-Length Encoding (RLE) using the RLE Lossless transfer syntax (UID 1.2.840.10008.1.2.5), as defined in the DICOM standard.
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