Automatic tone mapping
HyperHDR v21 introduced the feature of automatically enabling/disabling tone mapping depending on whether we are dealing with an SDR or HDR signal. It takes advantage of the fact that the captured raw HDR image is much darker and washed out than the SDR signal.
- Currently, the automatic tone mapping function only supports YUV/NV12/P010 codecs. It is possible that this list will be expanded in the future.
- The
Quarter of frame modeoption must be enabled in the grabber settings. This also limits the processor load, because the entire video frame is analyzed.
Select the "Image Processing" tab and scroll the page down.
In the configuration panel you can activate the automatic tone mapping function and also define the sensitivity thresholds for brightness (Y) and two components defining color (U, V) in range 0-255. The screenshot shows the default settings that should work for most grabbers. If you are using this feature only for movies, you can even try lowering the brightness threshold to 155. Setting the threshold too high can cause unwanted tone mapping in dark SDR scenes.
If the tone mapping off appears in unwanted circumstances when HDR material is played, it may mean that one of the thresholds is set too low. If this happens, open the HyperHDR logs and you will find there the value that exceeded one of the thresholds and based on it you can correct the configuration.
Here's an example of a very bright SDR signal (that replaced a previous HDR video) causing tone mapping to be disabled:
Later the HDR signal appears again and since it did not cause the thresholds to be exceeded for 30 seconds, tone mapping was automatically enabled.
