Why Convert JPG to HDR?
The Radiance HDR format stores images with vastly greater dynamic range than standard JPG files. While JPG uses 8 bits per channel (256 brightness levels), HDR uses a shared exponent encoding that spans over 76 orders of magnitude. This makes HDR essential for 3D rendering, visual effects, and professional lighting workflows where accurate luminance data matters.
Converting JPG to HDR prepares your images for use in applications like Blender, Maya, 3ds Max, and game engines that expect HDR input for environment mapping and image-based lighting. In our testing, converted files integrate seamlessly with standard 3D software workflows.
How to Convert JPG to HDR
- Upload your JPG file - Drag and drop or click to select your photo
- Confirm HDR as output format - The Radiance HDR format is selected by default
- Download your HDR file - Ready for use in 3D software and VFX pipelines
The entire conversion happens in your browser. No software installation, no account creation, no waiting in queues.
Understanding HDR Format
The Radiance HDR format (also called RGBE) was developed by Gregory Ward Larson at Lawrence Berkeley National Laboratory in 1985. It stores each pixel using four bytes: one byte each for red, green, and blue mantissas, plus a shared exponent. This achieves approximately 1% accuracy across an enormous brightness range.
HDR files use extensions like .hdr, .pic, or .rgbe. The format supports both uncompressed storage and run-length encoding for smaller file sizes. Unlike JPG's lossy compression that discards data, HDR preserves precise luminance values critical for realistic rendering.
Technical Specifications
- Color encoding - RGBE (Red, Green, Blue, shared Exponent)
- Bits per pixel - 32 bits (4 bytes) per pixel
- Dynamic range - Over 76 orders of magnitude
- Precision - Approximately 1% absolute accuracy
- Compression - Optional run-length encoding
JPG vs HDR: Key Differences
The fundamental difference lies in how each format handles brightness. JPG clips highlights and shadows to fit within 256 levels. HDR stores actual luminance values that can represent everything from starlight to direct sunlight in a single image.
| Feature | JPG | HDR (Radiance) |
|---|---|---|
| Bit depth | 8-bit per channel | 32-bit with shared exponent |
| Dynamic range | ~8 stops | 76+ orders of magnitude |
| File size | Smaller (lossy compression) | Larger (preserves luminance) |
| Use case | Web, sharing, display | 3D rendering, VFX, lighting |
| Color accuracy | Limited to display range | Scene-referred linear values |
For professional 3D work, HDR provides the luminance data that lighting calculations require. For sharing photos online, JPG remains the practical choice.
Primary Use Cases
3D Rendering and Environment Maps
HDR images serve as environment maps in 3D software, providing realistic lighting and reflections. When you wrap an HDR around your scene as a skybox, the renderer samples actual brightness values to illuminate your models. In our testing, even converted JPGs provide more consistent lighting than flat colors or gradients.
Visual Effects Integration
VFX artists use HDR light probes to match CG elements with live-action footage. Converting reference photos to HDR helps integrate them into compositing workflows, though professionals typically capture HDR data directly for critical shots.
Game Development
Game engines like Unreal and Unity use HDR textures for skyboxes and reflection probes. Converting JPG assets to HDR allows them to participate in the engine's lighting calculations rather than appearing as flat, unlit backgrounds.
Architectural Visualization
Archviz artists need accurate lighting to sell their renders. HDR environment maps create realistic ambient lighting and reflections on glass, metal, and other reflective surfaces.
Important Limitations
Converting a single JPG to HDR does not magically recover highlight or shadow detail that was clipped during the original capture. A blown-out sky in your JPG remains blown out in the HDR version. The conversion changes the container format and encoding, not the underlying data.
True HDR images typically come from:
- Exposure bracketing - Merging multiple photos at different exposures
- RAW processing - Extracting full sensor data from camera RAW files
- HDR capture - Purpose-built cameras or 360-degree HDR rigs
That said, JPG-to-HDR conversion remains valuable for format compatibility, pipeline integration, and situations where approximate HDR is sufficient.
Alternative Formats to Consider
Depending on your workflow, other formats might serve better:
- JPG to EXR - OpenEXR is the VFX industry standard, developed by Industrial Light and Magic. It offers more features including alpha channels, multiple layers, and various compression options.
- JPG to PNG - If you need lossless compression without HDR capabilities, PNG preserves quality without the complexity of HDR workflows.
- JPG to TIFF - TIFF supports higher bit depths and is widely used in print and photography workflows.
For pure 3D lighting work, EXR has become more common than Radiance HDR due to its flexibility. However, many legacy tools and workflows still expect HDR format specifically.
Batch Conversion
Working with multiple JPG files? Upload your entire collection and convert them all to HDR format at once. This is particularly useful when preparing texture sets or multiple environment references for a 3D project. No need to convert files one by one.
Browser-Based Processing
Our converter runs entirely in your browser using modern web technologies. Your JPG files are processed locally on your device:
- Windows, Mac, Linux, Chromebook
- Chrome, Firefox, Safari, Edge
- iPhone, iPad, Android devices
No software to download, no plugins to install, no accounts to create. Just upload your JPG and download your HDR file.