Image to HDR: A Complete Guide to Converting Images into High Dynamic Range Format

Introduction

HDR (High Dynamic Range) images are used to capture and display a wider range of brightness and color details than standard images. Converting an image to HDR format can significantly enhance its depth, contrast, and overall visual quality, making it ideal for photography, gaming, and CGI (Computer-Generated Imagery).

This guide will cover:

• What is the HDR is & how its works

• Benefits of converting an image to HDR

• Best tools to convert images to HDR

• Step-by-step methods for conversion

• Tips for optimizing HDR images

What is HDR?

HDR (High Dynamic Range) is an imaging technique that preserves details in both the brightest and darkest areas of an image. Standard images (like JPEG, PNG, or BMP) have a limited dynamic range, meaning they can lose detail in very bright highlights or dark shadows.

Key Features of HDR Format:

✅ High Dynamic Range – HDR images retain more details in shadows and highlights.
✅ 32-bit Color Depth – Unlike standard 8-bit or 16-bit images, HDR files support 32-bit floating-point precision.
✅ Used in Professional Imaging – HDR is commonly used in photography, VFX, and gaming.
✅ Supports Advanced Lighting Effects – Helps create realistic lighting in CGI and game development.
✅ Multiple HDR Formats – Common formats include Radiance HDR (.hdr), OpenEXR (.exr), and HDR10 for video.

Why Convert an Image to HDR?

There are several reasons why converting an image to HDR is beneficial:

1. To Recover Lost Details in Shadows & Highlights

HDR processing helps to restore hidden details in overexposed and underexposed areas.

2. For Better Image Quality in Photography

Photographers use HDR merging techniques to blend multiple exposures and enhance image clarity.

3. To Improve CGI & Game Graphics

HDR lighting and textures create realistic shadows, reflections, and highlights in games and 3D rendering.

4. For HDR-Compatible Displays

Modern HDR monitors, TVs, and gaming consoles support HDR10, Dolby Vision, and HDR10+ for improved visuals.

How to Convert an Image to HDR?

There are multiple ways to convert images into HDR using software tools, online converters, and specialized HDR techniques.

1. Convert an Image to HDR Using Photoshop

Adobe Photoshop allows you to convert a standard image into HDR format using 16-bit or 32-bit depth processing.

Steps to Convert an Image to HDR in Photoshop:

1. Open Adobe Photoshop and load your image (JPEG, PNG, TIFF, etc.).

2. Click Image > Mode > 32 Bits/Channel to convert the image to HDR mode.

3. Adjust brightness and contrast using Curves or HDR Toning (Image > Adjustments > HDR Toning).

4. Click File > Save As and choose Radiance HDR (.hdr) or OpenEXR (.exr).

5. Click Save to export your HDR image.

✅ Best for: Basic HDR conversion and photography enhancement.

2. Convert an Image to HDR Using Photomatix Pro

Photomatix Pro is a specialized tool for creating HDR images from multiple exposures.

Steps to Convert an Image to HDR in Photomatix Pro:

1. Open Photomatix Pro.

2. Click Load Bracketed Photos (or load a single image for tone mapping).

3. Adjust HDR settings such as exposure, contrast, and brightness.

4. Click Save As and choose HDR format (.hdr, .exr, or .tiff 32-bit).

✅ Best for: Professional HDR photography and exposure blending.

3. Convert an Image to HDR Using Luminance HDR (Free & Open-Source)

Luminance HDR is a free HDR tool that supports multiple HDR file formats.

Steps to Convert an Image to HDR in Luminance HDR:

1. Download and install Luminance HDR (available for Windows, macOS, and Linux).

2. Click File > Open and load your image.

3. Click Save As and choose Radiance HDR (.hdr) or OpenEXR (.exr).

4. Adjust HDR tone mapping settings if needed.

5. Click Save.

✅ Best for: Free HDR conversion and tone mapping.

4. Convert an Image to HDR Using Online Tools

If you prefer a quick conversion, you can use an online HDR converter.

✅ Popular Online HDR Converters:

• HDRConvert (https://hdrconvert.com/)

• Convertio (https://convertio.co/)

• OnlineConvert (https://www.onlineconvert.com/convert-to-hdr)

Steps to Convert an Image to HDR Online:

1. Open an HDR conversion website.

2. Upload your image (JPEG, PNG, BMP, etc.).

3. Choose HDR output format (.hdr, .exr, or .tiff 32-bit).

4. Click Convert and download the HDR file.

✅ Best for: Quick and basic HDR conversion without software installation.

5. Convert an Image to HDR Using MATLAB (For Advanced Users)

MATLAB can process HDR images using custom scripts.

Steps to Convert an Image to HDR in MATLAB:

1. Load your image:

   img = imread('image.jpg');

2. Convert to floating-point HDR:

   hdr_img = im2double(img);

3. Save as HDR:

   hdrwrite(hdr_img, 'output.hdr');

✅ Best for: Advanced users in research, image processing, and AI applications.

Best HDR File Formats

There are different types of HDR file formats, depending on the use case.

Tips for Optimizing HDR Images

1️⃣ Use High-Resolution Images – Start with high-quality images for better HDR results.
2️⃣ Adjust Exposure Levels – Correct highlights and shadows for realistic HDR effects.
3️⃣ Use HDR Tone Mapping – Tools like Photoshop and Luminance HDR allow fine-tuning of HDR contrast and brightness.
4️⃣ Choose the Right HDR Format – Use Radiance HDR (.hdr) for photography and OpenEXR (.exr) for 3D rendering.
5️⃣ Test on HDR Displays – Ensure your HDR image looks good on HDR-supported monitors and TVs.

Conclusion

Converting an image to HDR enhances brightness, contrast, and detail, making it ideal for photography, CGI, and HDR-compatible displays. Tools like Photoshop, Luminance HDR, and Photomatix Pro make the process easy, whether you’re working on professional projects or artistic edits.