Convert QOI to HDR

Drag and drop files here or click to select.
Max file size 100mb.

Uploading progress:

QOI vs HDR Format Comparison

Aspect	QOI (Source Format)	HDR (Target Format)
Format Overview	QOI Quite OK Image Format A modern lossless image format designed for simplicity and speed, created by Dominic Szablewski in 2021. QOI achieves compression ratios comparable to PNG while encoding 20-50x faster, using a custom lossless algorithm combining run-length encoding with difference and index-based pixel encoding. Modern Lossless	HDR Radiance RGBE High Dynamic Range A high dynamic range image format created by Greg Ward in 1985 for the Radiance lighting simulation system. HDR uses 32-bit floating-point values per channel to store luminance data that far exceeds the range of standard 8-bit images, capturing the full spectrum of visible light from darkest shadows to brightest highlights. Standard Lossless
Technical Specifications	Color Depth: 24-bit (RGB) or 32-bit (RGBA) Compression: Custom lossless (run-length + diff encoding) Transparency: Yes (RGBA mode) Animation: Not supported Extensions: .qoi	Color Depth: 32-bit float per channel (RGBE encoding) Compression: Run-length encoding (RLE) Transparency: Not supported Animation: Not supported Extensions: .hdr, .pic
Image Quality	Lossless — every pixel preserved exactly 24-bit RGB or 32-bit RGBA color modes No compression artifacts or quality degradation Pixel-exact reproduction on decode	32-bit float per channel captures extreme luminance range Dynamic range exceeds 76 orders of magnitude RGBE encoding preserves highlight and shadow detail Suitable for physically accurate lighting data
Processing & Tools	Process QOI files with command-line tools: # Convert QOI to other formats qoiconv input.qoi output.png # Using FFmpeg ffmpeg -i input.qoi output.png # Python with qoi library import qoi img = qoi.read("input.qoi")	Work with HDR files using imaging tools: # View HDR with ImageMagick magick display input.hdr # Convert with OpenCV (Python) import cv2 img = cv2.imread("input.hdr", cv2.IMREAD_ANYDEPTH) # Radiance tools ra_xyze -r input.hdr output.hdr
Advantages	Extremely fast encoding — 20-50x faster than PNG Extremely fast decoding — 3-4x faster than PNG Simple specification — under 300 lines of C reference code Lossless compression with zero quality loss Full RGBA transparency support Open specification with no patents or licensing fees	Captures full dynamic range of real-world scenes 32-bit float precision per channel Industry standard for environment maps and IBL Widely supported in 3D rendering applications Compact RGBE encoding reduces file size Essential for physically based rendering workflows
Disadvantages	Limited software support compared to PNG or JPEG No metadata or EXIF support No ICC color profile support No HDR or wide color gamut support No animation support Not supported by web browsers natively	No transparency (alpha channel) support Larger file sizes than standard 8-bit formats Requires tone mapping for display on standard monitors Limited web browser support Not suitable for general-purpose image distribution Older RGBE encoding less efficient than newer HDR formats
Common Uses	Game development asset pipelines Real-time rendering texture storage Intermediate format in image processing Embedded systems with limited CPU resources Screenshots in performance-critical applications	Environment maps for 3D rendering Image-based lighting (IBL) in CG production Architectural visualization and lighting simulation HDR photography post-processing Game engine skybox and reflection probes
Best For	Applications requiring ultra-fast encoding/decoding Game engines and real-time graphics pipelines Lossless image storage where speed matters Replacing PNG in speed-critical workflows	3D rendering and environment lighting Physically based rendering (PBR) workflows HDR photography and tone mapping Architectural lighting analysis
Version History	Introduced: 2021 (Dominic Szablewski) Current Version: QOI 1.0 specification Status: Modern, growing adoption Evolution: Single specification, focus on simplicity	Introduced: 1985 (Greg Ward, Radiance) Current Version: RGBE format (stable) Status: Established industry standard Evolution: Original Radiance format, widely adopted in 3D/CG industry
Software Support	Image Editors: GIMP (plugin), IrfanView, XnView, FFmpeg 5.1+ Web Browsers: Not natively supported OS Preview: Limited — requires plugins CLI Tools: qoiconv, FFmpeg, Pillow (plugin)	Image Editors: Photoshop, GIMP, Luminance HDR, Photomatix Web Browsers: Not natively supported 3D Software: Blender, Maya, 3ds Max, Unity, Unreal Engine CLI Tools: ImageMagick, OpenCV, Radiance tools, Pillow

Why Convert QOI to HDR?

Converting QOI (Quite OK Image Format) to HDR (Radiance RGBE) enables you to transform fast-encoded lossless images into high dynamic range files suitable for 3D rendering, environment mapping, and physically based lighting workflows. While QOI excels at speed and simplicity, HDR format provides the 32-bit floating-point precision needed for professional CG and visualization applications.

The primary advantage of this conversion is unlocking HDR capabilities for your QOI assets. The Radiance RGBE format stores luminance values that far exceed the 0-255 range of standard images, making it essential for environment maps, image-based lighting, and accurate light transport simulation in 3D rendering engines.

QOI files encoded with standard 8-bit color data can be mapped into the HDR floating-point space, preserving all original detail while enabling HDR-aware applications to process the image with extended precision. This is particularly useful when integrating QOI pipeline outputs into 3D rendering workflows that require HDR input formats.

Our free online converter handles the QOI to HDR transformation seamlessly, converting your images to Radiance RGBE format with proper floating-point encoding. Simply upload your QOI file and download the converted HDR result instantly.

Key Benefits of Converting QOI to HDR:

HDR Precision: Output uses 32-bit float per channel for extended dynamic range
3D Rendering Ready: HDR files work directly in Blender, Maya, Unity, and Unreal Engine
Environment Mapping: Create environment maps and IBL probes from QOI sources
Quality Preservation: All original QOI pixel data is accurately mapped to HDR space
Industry Standard: Radiance HDR is the established format for lighting and rendering
No Software Required: Convert directly in your browser with no installation needed
Instant Processing: Fast conversion with immediate download of the result

Practical Examples

Example 1: Game Texture to Environment Map

Scenario: A game developer has QOI texture assets and needs to convert them to HDR for use as environment maps in a physically based rendering pipeline.

Source: skybox_panorama.qoi (4.2 MB, 4096x2048px, RGB)
Format: QOI lossless, 24-bit color
Usage: Fast-captured panoramic skybox texture

Result: skybox_panorama.hdr (32-bit float per channel)

Workflow:
1. Capture panoramic skybox as QOI (fast encoding)
2. Convert to HDR for environment lighting
3. Load into Unreal Engine as IBL probe
* Extended dynamic range for realistic lighting
* Compatible with PBR material workflows
* Proper tone mapping applied at render time

Example 2: Architectural Visualization Lighting

Scenario: An architect has reference images captured as QOI files and needs HDR versions for Radiance lighting simulation software.

Source: interior_reference.qoi (3.1 MB, 3840x2160px, RGB)
Format: QOI lossless interior photograph
Captured: Reference lighting conditions

Result: interior_reference.hdr (Radiance RGBE format)

Benefits:
* Compatible with Radiance lighting simulation
* Floating-point values for accurate luminance
* Can be used as light source in rendering
* Preserves all captured detail from QOI source
* Standard format for architectural analysis tools

Example 3: Batch Asset Pipeline Conversion

Scenario: A VFX studio uses QOI as an intermediate format in their pipeline and needs to batch convert textures to HDR for compositing and final rendering.

Source: 30 QOI texture files (various resolutions, 150 MB total)
Format: QOI lossless pipeline intermediate
Pipeline: Render → QOI cache → HDR delivery

Result: 30 HDR files for compositing and rendering

Delivery workflow:
* Batch convert all QOI intermediates to HDR
* Load HDR files into Nuke/Fusion for compositing
* 32-bit float precision for color grading
* No banding artifacts in gradient areas
* Industry-standard format for VFX pipelines

Frequently Asked Questions (FAQ)

Q: What is HDR format?

A: HDR (High Dynamic Range) in the Radiance RGBE format is an image format created by Greg Ward in 1985. It stores pixel data as 32-bit floating-point values per channel, allowing it to represent a vastly wider range of luminance than standard 8-bit images. It is the industry standard for environment maps, lighting simulation, and 3D rendering.

Q: Will I lose quality converting QOI to HDR?

A: No. QOI is a lossless format, so all original pixel data is preserved. When converting to HDR, the 8-bit QOI values are accurately mapped into the 32-bit floating-point HDR space, retaining full fidelity of the source image.

Q: What software can open HDR files?

A: HDR files are supported by Adobe Photoshop, GIMP, Luminance HDR, Photomatix, and all major 3D applications including Blender, Maya, 3ds Max, Unity, and Unreal Engine. Command-line tools like ImageMagick and OpenCV also handle HDR files.

Q: Why would I need HDR instead of standard image formats?

A: HDR is essential when you need to preserve the full luminance range of a scene, particularly for 3D rendering, environment mapping, image-based lighting, and architectural visualization. Standard 8-bit formats clip highlight and shadow detail that HDR preserves.

Q: Is converting QOI to HDR free?

A: Yes! Our online converter transforms QOI files to HDR completely free with no registration, no watermarks, and no file count limits. Simply upload your QOI file and download the converted HDR.

Q: Can I use HDR files in game engines?

A: Yes, HDR files are widely used in game engines like Unity and Unreal Engine for environment maps, skyboxes, reflection probes, and image-based lighting. They provide the extended range needed for realistic PBR rendering.

Q: What are the file extensions for HDR?

A: Radiance HDR files use the extensions .hdr and .pic. Both extensions contain the same RGBE-encoded data and are interchangeable across applications that support the format.

Q: Can I convert HDR back to QOI?

A: While it is technically possible to convert HDR back to a standard format, the extended dynamic range will be tone-mapped down to 8-bit values, which may result in loss of highlight and shadow detail that the HDR format preserved.