Digital image processing and systems incorporating the same
Algorithms for improving the quality of images tone mapped using the bilateral filter are presented. The algorithms involve a localized operator applied to the tone mapping compression factor which enhances apparent image contrast in the low dynamic range output of the tone mapping. At least one embodiment of the present invention is related to circuitry configured to perform at least a portion of related calculations.
1. An apparatus, comprising:
circuitry for performing at least a portion of the calculations associated with an algorithm for mapping a high dynamic range digital image onto a display medium having a dynamic range lower than said high dynamic range digital image, said algorithm is configured to:
receive a high dynamic range digital image and decompose said high dynamic range digital image into an intensity layer and a color layer,
bilateral tone map said intensity layer to obtain a first contrast reduction factor,
modulate said first contrast reduction factor with a rational expression to obtain a second contrast reduction factor, wherein said rational expression is automatically adjusted to a compression factor based upon data from substantially an entire frame, and
alter said high dynamic range digital image using said second contrast reduction factor to obtain a second digital image having a dynamic range lower than said high dynamic range digital image.
2. An apparatus as in claim 1 configured to receive a series of high dynamic range digital images from a high dynamic range source and output a second series of digital images having a dynamic range lower than said series of high dynamic range digital images.
3. An apparatus as in claim 2 wherein said series of high dynamic range digital images is received at a rate greater than, or equal to, thirty images per second.
4. An apparatus as in claim 3 wherein said second series of digital images is output at a rate greater than, or equal to, thirty frames per second.
5. An apparatus, comprising:
circuitry for performing at least a portion of the calculations associated with an algorithm for mapping a high dynamic range digital image onto a display medium having a dynamic range lower than said high dynamic range digital image, said algorithm is configured to:
receive a high dynamic range digital image and decompose said high dynamic range digital image into an intensity layer and a color layer,
bilateral tone map said intensity layer to obtain a first contrast reduction factor,
modulate said first contrast reduction factor with a rational expression to obtain a second contrast reduction factor, wherein said rational expression is automatically adjusted to change a compression factor based upon data from substantially an entire frame, and
recombine said color layer and said intensity layer using said second contrast reduction factor to obtain a second digital image having a dynamic range lower than said high dynamic range digital image,
said apparatus further comprising circuitry for performing at least a portion of the calculations associated with an algorithm for calculating and supplying missing color data, said algorithm is configured to:
receive a spectrally mosaiced digital image and to calculate and supply missing color data, said algorithm implements a patterned based look-up table.
6. An apparatus as in claim 5 configured to receive a series of high dynamic range digital images from a high dynamic range source and output a second series of digital images having a dynamic range lower than said series of high dynamic range digital images.
7. An apparatus as in claim 6 wherein said series of high dynamic range digital images is received at a rate greater than, or equal to, thirty images per second.
8. An apparatus as in claim 7 wherein said second series of digital images is output at a rate greater than, or equal to, thirty frames per second.
9. An apparatus as in claim 5 configured to receive a series of mosaiced digital images from an imaging device and output a second series of digital images having missing color data added.
10. An apparatus as in claim 9 wherein said series of high dynamic range digital images is received at a rate greater than, or equal to, thirty images per second.
11. An apparatus as in claim 10 wherein said second series of digital images is output at a rate greater than, or equal to, thirty frames per second.