Tone Mapping Tool

Tone mapping is a technique used in image processing to convert high dynamic range (HDR) images into low dynamic range (LDR) images that can be displayed on standard screens. It compresses the wide range of luminance values while preserving details, colors, and contrast. Without tone mapping, HDR images would appear either washed out or with clipped highlights and shadows on regular displays.

Most consumer displays, monitors, and projectors have limited dynamic range (typically 8-bit, ~100:1 contrast ratio). HDR images captured by modern cameras or generated by 3D rendering software contain far more luminance information. A tone mapping tool lets you compress that information intelligently so you can view, share, and print HDR content without losing visual quality.

Reinhard tone mapping is a classic global operator that gracefully compresses highlights using a simple rational function. It produces natural-looking results but can sometimes desaturate bright areas. Filmic (ACES) tone mapping, based on the Academy Color Encoding System, creates a more cinematic "S-curve" that preserves color saturation in highlights and produces deeper shadows — ideal for film, games, and dramatic photography.

The Uncharted 2 tone mapping curve was developed by John Hable for Naughty Dog's game Uncharted 2. It uses a carefully crafted rational polynomial to create a pleasing filmic response curve. It excels at handling very bright highlights while maintaining rich mid-tones and deep shadows, making it a favorite among game developers and real-time rendering engineers.

This online tool accepts standard image formats (JPG, PNG, WebP). For true HDR formats like .hdr (Radiance) or .exr (OpenEXR), you may need to pre-convert them to a compatible format. However, the algorithms implemented here are the same professional-grade operators used in HDR processing software. You can use this tool to preview and learn how different tone mapping curves affect your images.

Exposure adjusts the overall brightness before tone mapping is applied — simulating how the image was exposed in-camera. Increasing exposure brightens the image (useful for recovering shadow detail), while decreasing it darkens the image (helpful for saving blown-out highlights). The tone mapping algorithm then compresses the adjusted range into viewable output.

The White Point parameter (used in Reinhard Extended) controls which luminance value maps to pure white. Lower values create a brighter, more ethereal look; higher values preserve more highlight detail but can make the image appear darker. Typical values range from 2 to 8. A value of 4 is a good starting point for most images.

It depends on your creative intent: Reinhard is great for natural, documentary-style images. Filmic/ACES works well for cinematic, dramatic looks. Uncharted 2 excels at balancing bright highlights with rich mid-tones. Simple Gamma is a quick, classic adjustment. Experiment with the presets (Natural, Cinematic, Punchy, etc.) to quickly find a starting point, then fine-tune the parameters.

Not exactly. HDR photography captures multiple exposures and merges them into a single high-dynamic-range image. Tone mapping is the next step — it converts that merged HDR result into a viewable LDR image. Some HDR photo software applies aggressive tone mapping to create hyper-real "HDR look" images, but professional tone mapping aims for natural or cinematic results without halos or oversaturation.

Yes! Once you're satisfied with the tone mapping result, click the Download button to save the processed image as a high-quality PNG file. The downloaded image matches exactly what you see in the preview.