Method and system for eliminating artifacts in overlapped projections

Claim 3

The method according to claim 1 , wherein said adjusting said intensity of said first predetermined color pixels is for calibration of said projector for developing a set of transfer functions.

Claim 4

The method according to claim 2 , further comprising: using said transfer functions to remap any possible pixel value across a display screen.

Claim 5

The method according to claim 1 , wherein said first predetermined color pixels comprise black pixels.

Claim 6

The method according to claim 1 , wherein said second predetermined color pixels comprise white pixels.

Claim 7

The method according to claim 1 , further comprising: performing a mapping function to change a value of said first and second predetermined color pixel values to achieve said uniform intensity.

Claim 8

The method according to claim 6 , wherein said mapping function comprises a linear mapping function.

Claim 9

The method according to claim 7 , further comprising: determining and calibrating parameters of the linear mapping function.

Claim 10

The method according to claim 7 , wherein said performing a mapping function comprises using a plurality of color maps for said mapping function.

Claim 11

The method according to claim 7 , wherein said performing a mapping function comprises using alpha blending for said mapping function.

Claim 12

The method according to claim 10 , wherein said alpha blending for implementing the mapping functions comprises generating an image using a rendering such that said frame buffer includes at every pixel an unmapped pixel intensity.

Claim 13

The method according to claim 10 , wherein a function of said alpha blending function includes p·αp+q·1, and wherein said blending function computes an incoming pixel value by first multiplying a current stored pixel value with the alpha-value of the incoming pixel and then adding the incoming pixel value.

Claim 14

The method according to claim 6 , wherein said mapping function is selected such that said mapping function matches a transfer function of a respective projector of said plurality of projectors.

Claim 15

The method according to claim 6 , wherein said mapping function comprises a scaling and an offset operation.

Claim 16

The method according to claim 14 , wherein said mapping function is computed by m 1  ( p ) = w 1 - b 4 w 1  p + b 4   m 2  ( p ) = w 2 - b 2 w 1  p + b 2   m 4  ( p ) = w 4 - b 1 w 1  p + b 1 . ( 1 )

Claim 17

The method according to claim 14 , wherein said mapping function defines different color maps for different areas of said screen, and wherein a color table is set up such that for each input pixel value a desired output pixel value is produced.

Claim 18

The method according to claim 15 , wherein a function of said alpha blending function comprises p·∝p+q·1, and wherein said blending function computes the incoming pixel value by first multiplying the current stored pixel value with the alpha-value of the incoming pixel and then adding the incoming pixel value.

Claim 19

The method according to claim 17 , wherein, after writing to an alpha plane in the frame buffer is disabled, a predetermined shape is rendered for every screen region having an overlapped portion, and wherein for each predetermined shape, the alpha value is set to the corresponding scale factor ∝p and the color value to the offset value q and after rendering the predetermined shapes, the frame buffer contains the properly mapped pixel values and is projected to the screen.

Claim 20

The method according to claim 18 , wherein said predetermined shapes comprises a rectangle adjacent respective overlap regions.

Claim 21

The method according to claim 1 , wherein said adjusting said intensity comprises utilizing a gamma correction table for linearizing a respective transfer function of each of said projectors.

Claim 22

The method according to claim 1 , further comprising: remapping input pixel values using a transfer function to display output pixel values on a display screen, wherein parameters w i and b i of said transfer function are determined by disabling said mapping function, and then displaying the first predetermined color pixels by all projectors.

Claim 23

The method according to claim 21 , wherein said adjusting said intensity, with four overlapping image tiles, increments a value of pixels in areas with two overlapping tiles until their intensity matches the intensity of pixels in areas with four overlapping image tiles, said pixel value being represented by b 2 .

Claim 24

The method according to claim 22 , wherein said adjusting said intensity increments the value of pixels in areas with no overlapping tiles until their intensity matches the intensity of pixels in areas with four overlapping tiles, and represents a pixel value thereof by b 4 .

Claim 25

The method according to claim 23 , wherein said adjusting said intensity further displays said second predetermined color pixels with one projector at a time, while others of said plurality of projectors are set to said first predetermined color for all pixels, and decrements a value of pixels in areas with two overlapping tiles until their intensity matches the intensity of pixels with no overlapping tiles, wherein a pixel value is represented by w 2 .

Claim 26

The method according to claim 24 , wherein said adjusting said intensity further decrements the value of pixels in areas with four overlapping tiles until their intensity matches the intensity of pixels with no overlapping tiles, and represent s a resulting pixel value with w 4 .

Claim 27

The method according to claim 25 , wherein said adjusting said intensity uses the values w i and b i to establish the mapping functions m i for said projectors.

Claim 28

The method according to claim 1 , wherein said scaling of said values of said second predetermined color pixels is performed prior to said adjusting of said intensity of said first predetermined color pixels.

Claim 31

The method according to claim 28 , wherein said performing a calibration process comprises: prior to said determining said areas, in areas outside of the overlap areas, adjusting an intensity of first predetermined color pixels to match an intensity of the first predetermined color pixels in the overlap areas; and simultaneously with said adjusting, scaling values of second predetermined color pixels in the overlap areas such that said values do not exceed the maximum pixel value of a single projector of said plurality of projectors.

Claim 32

A projection system, comprising: a display screen; a plurality of projectors each for producing a respective image portion for being displayed on said screen, a plurality of image portions forming a composite image having a plurality of pixels, said plurality of image portions having overlapping image areas; and an intensity adjuster, coupled to said projectors, for adjusting an intensity of first predetermined color pixels of said plurality of pixels across said screen, to achieve uniform intensity of said first predetermined color pixels, wherein said system performs a calibration process by adjusting an intensity of said first predetermined color pixels in non-overlapping areas to match an intensity of the predetermined color pixels in the overlapping image area, and scaling values of second predetermined color pixels in the overlapping image area such that said values do not exceed a maximum pixel value of a single prompter of said plurality of projectors.

Claim 33

A projection system, comprising: a display screen; a plurality of projectors each for producing a respective image portion for being displayed on said screen, a plurality of image portions forming a composite image having a plurality of pixels, said plurality of image portions having overlapping image areas; and an intensity adjuster, coupled to said projectors, for adjusting an intensity of first predetermined color pixels of said plurality of pixels across said screen, to achieve uniform intensity of said first predetermined color pixels, wherein said system performs a calibration process by adjusting an intensity of said first predetermined color pixels in non-overlapping areas to match an intensity of the predetermined color pixels in the overlapping image area, and scaling values of second predetermined color pixels in the overlapping image area such that said values do not exceed a maximum pixel value of a single prompter of said plurality of projectors.

Claim 34

The system according to claim 30 , further comprising: a scalar, coupled to said intensity adjuster, for scaling values of second predetermined color pixels in the overlap areas, simultaneously with said adjusting of said intensity by said intensity adjuster.

Claim 35

The system according to claim 31 , wherein said predetermined pixels comprise white pixels.

Claim 36

The system according to claim 30 , wherein said predetermined pixels comprise black pixels.

Claim 37

The system according to claim 30 , wherein said intensity adjuster performs a mapping function to change a value of said predetermined pixel values to achieve said uniform intensity.

Claim 38

The system according to claim 34 , wherein said mapping function comprises a linear mapping function.

Claim 39

The system according to claim 35 , further comprising: means, coupled to said intensity adjuster, for determining and calibrating parameters of the liner mapping function.

Claim 40

The system according to claim 36 , wherein said intensity adjuster comprises a plurality of color maps for said mapping function.

Claim 41

The system according to claim 36 , wherein said intensity adjuster comprises means for alpha blending values of said pixels for said mapping function.

Claim 42

The system according to claim 30 , further comprising: means for determining areas in which each of a plurality of displayed pixels are located; and means for applying a mapping function to said displayed pixels, newly-mapped pixels being displayed on said display screen.

Claim 43

A projection system, comprising: a plurality of projectors for projecting image portions onto said screen, at least some of said image portions having overlapping portions; wherein in areas outside of the overlap areas, an intensity of predetermined color pixels is adjusted to match the predetermined color level in the overlap areas, and simultaneously, the pixel values are scaled in the overlap areas such that they never exceed the maximum pixel value of a single projector.

Claim 44

A projection system, comprising: a plurality of projectors for projecting image portions onto said screen, at least some of said image portions having overlapping portions; wherein in areas outside of the overlap areas, an intensity of predetermined color pixels is adjusted to match the predetermined color level in the overlap areas, and simultaneously, the pixel values are scaled in the overlap areas such that they never exceed the maximum pixel value of a single projector.

Claim 45

The system according to claim 40 , further comprising: an intensity adjuster for adjusting said intensity of said predetermined color pixels of said image.

Claim 46

The system according to claim 40 , wherein, in overlapping areas, the maximum pixel values of the predetermined color pixels are limited such that the sum of all pixel intensities provided by the projectors does not exceed said maximum.

Claim 47

The system according to claim 40 , wherein a mapping function is selected such that said mapping function matches a transfer function of a respective projector of said plurality of projectors.

Claim 48

A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a method for computer-implemented eliminating visible artifacts in overlapped projections produced by a plurality of projectors, said method comprising: in areas outside of the overlap areas, adjusting an intensity of predetermined color pixels to match an intensity of the predetermined color pixels in the overlap areas; and simultaneously with said adjusting, scaling values of pixels in the overlap areas such that said values do not exceed the maximum pixel value of a single projector of said plurality of projectors.

Claim 49

A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a method for computer-implemented eliminating visible artifacts in overlapped projections produced by a plurality of projectors, said method comprising: in areas outside of the overlap areas, adjusting an intensity of predetermined color pixels to match an intensity of the predetermined color pixels in the overlap areas; and simultaneously with said adjusting, scaling values of pixels in the overlap areas such that said values do not exceed the maximum pixel value of a single projector of said plurality of projectors.

Claim 50

The signal-bearing medium according to claim 44 , wherein said method further comprises: determining areas in which each of a plurality of displayed pixels are located; applying a mapping function to said displayed pixels; and causing said newly-mapped pixels to be displayed.