How to Tone Map HDR Images in Photomatix Pro

Launch Photomatix Pro and generate high dynamic range photographs on the fly or load a saved HDR image. With the HDR image ready and onscreen in Photomatix Pro, complete the following steps to tone map it:

  1. Invoke the tone mapping process by clicking the Tone Mapping button or by choosing Process→Tone Mapping.

    image0.jpg

    This launches the Details Enhancer, as shown in the next step. You can switch tabs between the Details Enhancer and Tone Compressor at any time.

  2. Load baseline settings by choosing a preset option from the Presets drop-down list, or by adjusting the settings in the Details Enhancer by hand.

    image1.jpg

    Each time you load an image to tone map, reset the controls manually (which takes time) or with the help of a preset that you created beforehand. The purpose of this step is to create a fairly neutral starting point for all your photos.

    If you choose the preset route, select Default from the Presets drop-down list (seen near the bottom of the Details Enhancer window). Or create a preset of your own to load when you need by selecting Save Settings from the Presets menu (your current settings are saved with the filename of your choice).

  3. Analyze the image.

    image2.jpg

    Look at the effect your baseline settings have on the HDR image, as shown.

    Sometimes what you see is good; sometimes bad, and sometimes in between. Don’t expect it to be perfect. The point is to use this as a starting point. If you have other baselines for different conditions or artistic effects (interiors, exteriors, strong, realistic, and so on), load them and see what they look like. Sometimes you will be surprised.

    Examine your reaction and use that as an indicator as to where the image could be changed. Think in terms of these characteristics:

    • Overall brightness: Is the image too bright, too dark, or just right? Use the histogram to see a graph of where the pixels are distributed in the image, from dark to light. This figure illustrates an area of the image that is very bright, and even needs to be toned down some.

      image3.jpg
    • Light balance: Sometimes certain areas of the image are too dark or too light. Compare adjacent areas that have different balances of brightness and tone. Pay attention to tonal differences where they meet, such as between the floor and counter (high contrast but uniform), the ceiling and decor (close in contrast), and the upper floor structural area (smaller areas with differing contrasts).

      Come up with solutions rather than simply observe. The counter should be more vibrant compared with the floor; the mural should have more contrast than the wall; the lights in the upper areas are too bright. These things should be corrected.

      image4.jpg
    • Image contrast: Does the image look like a light gray overlay is on top of it? If so, there is not enough image contrast. In this case, the floor and stone table reveal that there isn’t enough overall contrast in the image.

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    • Details: Are the details visible enough? Do they pop? Details can be accentuated or smoothed by adjusting local contrast settings. Part of the mural is shown in this figure. It looks bright enough, but there could be much better contrast.

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    • Noise: What is the noise level? Is it acceptable, or has it been accentuated? Figure 9-8 illustrates a good place to find noise: areas of fairly consistent color and texture. It’s easy to spot some noise here — nothing drastic, but you might want to take care of this later, after tone mapping.

      image7.jpg
    • Color intensity: Does the image need more color or less color? Is this need confined to highlights, shadows, or the entire image? This figure shows another side of the mural against one end of the main lobby. The colors look nice and saturated, but enhancing contrast will show them off better.

      image8.jpg
    • Temperature: Does the image have a blue or reddish color cast to it? If so, this indicates a color temperature problem. There is pretty good temperature in this image. The floor looks gray, the white panels look white, and the black computer monitor looks black.

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