Method and apparatus for acquiring HDR flash images
View Patent ↗A method generates a high dynamic range image by first acquiring a set of images of a scene illuminated by different lighting conditions. The set of images are then combined to generate a high dynamic range image.
1. A method for generating a high dynamic range image, comprising the steps of:
acquiring a set of images of a scene illuminated with a flash unit having a different power setting for each acquired image in the set;
generating a gradient image for each image in the set; and
combining the set of gradient images to generate a high dynamic range image.
2. The method of claim 1 , further comprising:
applying one-valued tone mapping to the high dynamic range image to render the high dynamic range output image.
3. The method of claim 1 , in which each image includes a plurality of pixels, and the combining further comprises:
least-squares estimating of an intensity for each pixel in the high dynamic range image using intensity values of corresponding pixels in the set of images.
4. A method for generating a high dynamic range image, comprising the steps of:
acquiring a set of images of a scene illuminated with a flash unit having different power settings and using different exposure times;
generating a gradient image for each image in the set; and
combining the set of gradient images to generate a high dynamic range image.
5. The method of claim 4 , further comprising:
applying two-valued tone mapping to the set of images to render the high dynamic range image.
6. The method of claim 4 , in which each image includes a plurality of pixels, and the combining further comprises:
least-squares estimating of an intensity for each pixel in the high dynamic range image using intensity values of corresponding pixels in the set of images.
7. A system for generating a high dynamic range output image, comprising:
a camera configured to acquire a set of images of a scene illuminated with a flash unit having different power settings;
means for generating a gradient image for each image in the set; and
means for combining the set of gradient images to generate a high dynamic range image.
8. A system for generating a high dynamic range output image, comprising:
a camera configured to acquire a set of images of a scene illuminated with a flash unit having different power settings while also using different exposure times;
means for generating a gradient image for each image in the set; and
means for combining the set of images to generate a high dynamic range image.
9. A method for generating a high dynamic range image, comprising the steps of:
acquiring a set of images of a scene illuminated by different lighting conditions;
generating a gradient image for each image in the set; and
combining the set of gradient images to generate a high dynamic range image.
10. The method of claim 9 , further comprising:
rendering the high dynamic range image by applying tone mapping to the set of images.