Convert HDRU to CAL

The quick and simple way to convert HDRU to CAL files is to use a quality batch conversion software, such as reaConverter.

reaConverter offers offline file conversion between numerous formats, including HDRU to CAL, plus additional image editing tools for enhanced file preparation.

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How to Convert Multiple HDRU Files to CAL?

1. Download and Install reaConverter

reaConverter is quick to download, install and launch. This standalone software is extremely efficient in managing a wide range of batch conversions. reaConverter is incredibly powerful and boasts an extensive variety of features.

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Install reaConverter

2. Load your HDRU files

Start reaConverter and load all the .hdru files you intend to convert into .cal. The software supports multiple HDRU conversion and processes all files locally on your computer.

Select HDRUs from a folder or by drag-and-dropping them directly into the reaConverter window.

Load your HDRU files into reaConverter

3. Select CAL as output format

Pick the CAL as output format and choose the destination folder where you want to save new .cal files.

Select CAL as output format

4. Start HDRU to CAL conversion

Then simply press Convert button and your conversion will begin in no time!

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Once the conversion is complete, you can find your CAL files in the destination folder you selected.

HDRU to CAL offline

reaConverter offers the fastest, simplest solution for converting your HDRU files into CAL in seconds - all files processed on your PC for maximum privacy and speed.

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Do more with your files

Converting HDRU files for use in a workflow? reaConverter offers many ways to process files, so you can customize them according to your requirements.

Our range of editing options includes auto-processing options such as auto-rotate, auto-crop, watermarking and more. Change Color Space, copy Metadata, set DPI, manage ICC Profile, control Bit Depth.

Conversion features
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User Reviews

Average User Rating:
Last updated on April 23, 2025
"The step-by-step video makes conversion foolproof. I'd recommend this to my grandma - it's that well-explained!"
DeShawn M. Thompson
Happy User
"I'm really impressed with this software - it converts files between formats incredibly fast!"
Lin Zhang
Happy User
"I firmly believe working with JPEG — the universal format supported by all devices and apps—is the wisest choice. reaConverter handles these conversions flawlessly."
Ava Thomas
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"We deployed reaConverter across our department to standardize file formats for our archives. The command-line support and automation features integrated perfectly into our systems. Stellar performance and zero crashes—it just works."
David R.
IT Solutions Architect
"So simple! I just needed to convert a couple of files to another format, and for such a straightforward task, the online converter worked perfectly — delivering the files I needed in no time. Excellent service!"
Kenneth D. Carter
Satisfied Customer
"I run a small design agency, and reaConverter has saved me countless hours. The batch processing is lightning-fast, and the ability to convert hundreds of files into different formats at once is a game-changer. Highly recommend!"
Mark T.
Satisfied Customer

HDRU to CAL Conversion: FAQ

What are HDRU files?

HDRU is a rare image format associated with a currently obsolete image handling program called Apollo HRDU. HDRUs are considered old and uncommon, and are difficult to open with regular image viewers, but in case you found one it's probably best to convert to a more accessible extension, such as JPG or PNG.

What are CAL files?

A CAL image file represents a monochrome bitmap image that uses the CALS raster image standard for storing graphics data. This standard was created in the 1980s by the US Department of Defence as a compressed interchangeable image format. CAL and CALS are extensions used for similar purposes.

Can reaConverter convert HDRU to CAL?

Yes! reaConverter instantly converts .hdru to .cal with perfect quality preservation. With its batch processing feature, you can convert multiple files at once in just a few clicks. You can even convert images directly from Windows Explorer using the right-click menu — fast and convenient.

Can I convert HDRU to CAL online?

If you only need to convert a few HDRU files to CAL format, feel free to try our free online free online HDRU to CAL converter — perfect for small batches with no installation needed!

How can I turn HDRU files into CAL on my computer?

The best way to change HDRUs to CALs on your PC is to install 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 HDRU to CAL.

How can I automate HDRU to CAL files conversion?

reaConverter supports all the most useful automation features such as Right-click сonversion and Watch Folders for the most efficient automated files conversion in any software of this type.

Is there a way to convert HDRU files to CAL using the command prompt?

reaConverter provides full access to all its features via Windows command line, including a high-performance command-line hdru to cal converter for batch processing.

What else can I do with reaConverter?

Convert CAD formatsSet picture bit depthConvert RAW formatsConvert GIS filesConvert DICOM images

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