HDR Tone Mapping

What is Tone Mapping?

Tone mapping compresses the tonal values of a high dynamic range image into a lower one. The result is an image with more visible details that would not be seen on an image with lower dynamic range.

How does Tone Mapping Work?

Tone mapping works by merging multiple images with different exposures into one image. Each image contains details not visible in another. To take these images, use the Automatic Exposure Bracketing feature on your camera to capture three images of different exposures. You may need to place your camera on a tripod to prevent camera movement.

Three 8-bit images with different exposures tone mapped into a single 8-bit image with greater detail.

Tone Mapping Methods

Most common methods :
  • Using Adobe Photoshop to merge the images into a HDR file then converting the image to an 8-bit file using local adaptation.
  • Using HDRsoft Photomatix to create a HDR file then tone mapping the HDR file into a 8-bit file.
The latter usually produces better results that Adobe Photoshop isn’t capable of producing. If you don’t have Photomatix, here’s a Photoshop solution for tone mapping:
Layered Tone Mapping with Photoshop
Although Photomatix produces amazing results and Photoshop’s local adaptation methods can create satisfactory results, none of them can produce a layered file. In this Photoshop CS3 tutorial, you’ll learn how to tone map three exposures with results better than Photoshop CS3′s local adaptation and similar to Photomatix tone mapping. In addition, the document will have seperate layer allowing advance Photoshop users to tweak their image with greater control.