Method and arrangement for optimizing a luminance characteristic curve
AssigneeSiemens Aktiengesellschaft
InventorsWolfgang Eckhardt, Andreas Kaercher, Uwe Nagel, Hartmut Schulz
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Abstract
A method and an arrangement for optimizing the luminance characteristic curve for a display system using a lookup table. Digitized video levels are supplied to this lookup table and are optimized using correction values stored in the lookup table. With suitable means, the luminance characteristic curve can be easily adapted to standards and/or custom specifications. The memory requirement is low, since it is not necessary to provide different lookup tables for different ambient luminosities or selected reproduction models (curves).
Claims12
A method for optimizing a luminance characteristic curve for a display system using a lookup table, to which digitized video levels are supplied, using correction values stored in the lookup table, comprising:
- determining natural response luminance characteristic data of a test image without the influence of ambient light during a presetting phase;
- storing said natural response luminance characteristic data;
- specifying a desired luminance characteristic during a selection phase;
- detecting a change in an illumination of the display system based on an actual ambient light during a normal operating mode;
- calculating correction values during this normal operating mode by taking into account the detected illumination, the desired luminance characteristic, and the natural response luminance characteristic data;
- and storing the correction values in the lookup table.
An arrangement for optimizing a luminance characteristic curve for a display system with a lookup table, to which digitized video levels are supplied, using correction values stored in the lookup table, comprising:
- a first determining means which determines natural response luminance characteristic data of a test image without the influence of ambient light, during a presetting phase;
- a first storing means which stores the natural response luminance characteristic data in a first memory;
- a second storing means which stores luminance values of a desired luminance characteristic, during a selection phase, in a second memory;
- a detection means which detects a change in an illumination of the display system due to the current ambient light during a normal operating mode;
- a second determining means which determines correction values, by taking into account the detected illumination, the desired luminance characteristic, and the natural response luminance characteristic data;
- and
- a third storing means which stores the correction values in the lookup table.
A method for adjusting a luminance characteristic curve for a display system comprising:
- storing desired luminance characteristic values corresponding to a desired luminance characteristic curve in a lookup table;
- storing natural response luminance values in said lookup table corresponding to a luminance response of said display system to test images without an influence of ambient light;
- detecting ambient light illumination of said display system during normal operation;
- adjusting a range of luminances output by said display system based on the detected ambient light illumination;
- scaling said stored natural response luminance values to correspond to said adjusted range of luminances output by said display system;
- storing video input levels corresponding to a video signal in said lookup table;
- calculating adjusted video output levels which correspond, respectively, to said video input levels;
- and
- supplying said adjusted video output levels to said display system;
- wherein said adjusted video output levels are calculated by a calculation procedure comprising:
- determining an adjusted luminance level of said display system for each video input level based on said stored desired luminance characteristic values;
- and
- calculating a corresponding adjusted video output level necessary to achieve said desired luminance level based on said stored natural response luminance values.
An apparatus for adjusting a luminance characteristic curve for a display system comprising:
- a memory configured to store a lookup table;
- wherein said lookup table comprises desired luminance characteristic values corresponding to a desired luminance characteristic curve;
- and
- wherein said lookup table further comprises natural response luminance values corresponding to a luminance response of said display system to test images without an influence of ambient light;
- a detector configured to detect ambient light illumination of said display system during normal operation;
- a controller configured to adjust a range of luminances output by said display system based on the detected ambient light illumination;
- a processor configured to scale said stored natural response luminance values to correspond to said adjusted range of luminances output by said display system;
- an input device configured to input a video signal;
- a video signal processor configured to store video input levels corresponding to said video signal in said lookup table;
- a calculator configured to calculate adjusted video output levels which correspond, respectively, to said video input levels;
- and
- an output device configured to output said adjusted video output levels to said display system;
- wherein said video output levels are calculated by a calculation procedure comprising:
- determining an adjusted luminance level of said display system for each video input level based on said stored desired luminance characteristic values;
- calculating a corresponding adjusted video output level necessary to achieve said adjusted luminance level based on said stored natural response luminance values.
Dependencies are inferred from the claim text.