System and method for real-time tone-mapping

1. A method for filtering an input image to generate a base layer and a detail layer, the method comprising:

applying a spatial filter to the input image to generate the base layer and the detail layer, the filtering comprising for each of a plurality of pixels:

detecting the presence of an edge of the input image within a region surrounding the pixel; and

selectively applying a filtering kernel to the region based on the presence of the edge within the region.

2. The method of claim 1 , wherein the spatial filter is applied iteratively, the size of the filtering kernel being increased in each iteration;

wherein the flow of filtering across iterations for a given pixel is stopped upon determining a gradient within the region surrounding the given pixel being greater than a predetermined edge threshold representing the presence of an edge within the region.

3. A method for tone mapping the input image to generate a tone-mapped output image, the method comprising:

a) filtering the input image according to claim 1 ;

b) tone-mapping the base layer; and

c) combining the detail layer and the tone-mapped base layer.

4. The method of claim 3 , further comprising modulating the detail layer based on a visibility threshold; and

wherein the modulated detail layer is combined with the tone-mapped base layer.

5. A context-aware tone-mapping operator for tone-mapping an input image, the operator comprising:

a) a noise model generator configured to generate a noise model of the input image;

b) a tone-mapping module operable to receive one or more contextual parameters, the tone-mapping module comprising:

i) an edge stopping filtering submodule for extracting a base layer of the input image and a detail layer of the input image according to the method of claim 1 ;

ii) a tone-curve generating submodule for tone mapping the base layer of the input image based on the noise model of the input image; and

iii) a combining submodule for combining the tone-mapped base layer and the detail layer;

c) wherein at least one of the edge stopping filtering submodule, the tone-curve generating submodule and the combining submodule is adjustable based on at least one of the one or more contextual parameters.

6. The tone-mapping operator of claim 5 , wherein the contextual parameters comprise one or more of a viewer characteristic, ambient light, peak luminance of an output display device, ambient reflectance, dynamic range of the output display device, user-defined parameters, speed and exposure.

7. The tone-mapping operator of claim 5 , wherein the contextual parameters comprise one or more of ambient light, peak luminance of an output display device, dynamic range of the output display device and exposure; and

wherein the tone-curve generating submodule determines an effective output dynamic range based on the one or more of the ambient light, the peak luminance and dynamic range and generates a tone-curve for tone mapping the base layer based on the effective output dynamic range.

8. The tone-mapping operator of claim 5 , wherein the contextual parameters comprise viewer characteristic; and

wherein the combining submodule modulates the detail layer based on the viewer characteristic and combines the base layer with the modulated detail layer.

9. The tone-mapping operator of claim 8 , wherein the contextual parameters comprise viewer preferences; and

wherein the tone-curve generating submodule generates a tone-curve for tone-mapping based on the viewer preferences.

10. The tone-mapping operator of claim 5 , wherein the contextual parameters comprise speed; and

wherein the edge stopping filter submodule is configured to apply a number of iterations according to the speed.

11. The tone-mapping operator of claim 5 , wherein the contextual parameters comprise viewer preferences; and

wherein the tone-curve generating submodule generates a tone-curve for tone-mapping based on the viewer preferences and the combining submodule modulates the detail layer based on the viewer preferences and combines the base layer with the modulated detail layer.

12. A computer-implemented system for filtering an input image to generate a base layer and a detail layer, the system comprising:

at least one data storage device; and

at least one processor coupled to the at least one storage device, the at least one processor being configured for:

filtering the input image according to claim 1 ;

tone-mapping the base layer; and

combining the detail layer and the tone-mapped base layer.

13. The system of claim 12 , wherein the at least one processor is further configured for modulating the detail layer based on a visibility threshold; and

wherein the modulated detail layer is combined with the tone-mapped base layer.

14. A computer-implemented system for filtering an input image to generate a base layer and a detail layer, the system comprising:

at least one data storage device; and

at least one processor coupled to the at least one storage device, the at least one processor being configured for:

applying a spatial filter to the input image to generate the base layer and the detail layer, the filtering comprising for each of a plurality of pixels:

detecting the presence of an edge of the input image within a region surrounding the pixel; and

selectively applying a filtering kernel to the region based on the presence of the edge within the region.

15. The system of claim 14 , wherein the spatial filter is applied iteratively, the size of the filtering kernel being increased in each iteration;

wherein the flow of filtering across iterations for a given pixel is stopped upon determining a gradient within the region surrounding the given pixel being greater than a predetermined edge threshold representing the presence of an edge within the region.