Methods and Systems for Area Adaptive Backlight Management
First Claim
Patent Images
1. A method for modifying display backlight target values, said method comprising:
- a) receiving an initial backlight target value image, BL0;
b) establishing an initial LED driving value (led0) image comprising virtual points located between pixel elements of said input image by convolving said BL0 image with an LED mask comprising said virtual point locations;
c) determining an approximated backlight image (bl1) by convolving said led0 image with a truncated point spread function (psf2) kernel;
d) determining a backlight deficiency image (bl2), which based on a difference between said BL0 image and said bl1 image;
e) creating a compensated backlight image (bl3) by convolving said bl2 image with a diffusion kernel; and
f) determining a modified LED target value image (BL1) by adding said bl3 image to said BL0 image.
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Abstract
Elements of the present invention relate to systems and methods for generating, modifying and applying backlight array driving values.
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Citations
20 Claims
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1. A method for modifying display backlight target values, said method comprising:
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a) receiving an initial backlight target value image, BL0; b) establishing an initial LED driving value (led0) image comprising virtual points located between pixel elements of said input image by convolving said BL0 image with an LED mask comprising said virtual point locations; c) determining an approximated backlight image (bl1) by convolving said led0 image with a truncated point spread function (psf2) kernel; d) determining a backlight deficiency image (bl2), which based on a difference between said BL0 image and said bl1 image; e) creating a compensated backlight image (bl3) by convolving said bl2 image with a diffusion kernel; and f) determining a modified LED target value image (BL1) by adding said bl3 image to said BL0 image. - View Dependent Claims (2, 3)
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4. A method for generating a modified LED target value image for a display backlight array, said method comprising:
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a) receiving a target backlight image (BL1); b) combining said BL1 image with an LED mask, comprising virtual points interspersed between actual image points, to create an led1 image; c) convolving said led1 image with a point spread function (PSF) to create an approximated backlight image, BL2; d) determining a difference image representing the difference between said target backlight image, BL1, and said approximated backlight image, BL2; e) determining a scaling factor, β
;f) scaling said difference image with said scaling factor thereby creating a scaled difference image; g) adding said led1 image to said scaled difference image to create a revised LED image, ledi+1; and h) setting values in said revised, ledi+1, image to zero when said valued are less than zero. - View Dependent Claims (5, 6)
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7. A method for post-processing backlight image driving values for a display backlight array, said method comprising:
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a) receiving a backlight image comprising backlight image driving values; b) finding a backlight image driving value, ledi,j, in said backlight image, that is greater than one; c) calculating coefficients for neighbors of said driving value, ledi,j, with the following equations;
Ci−
1,j=max(0,1−
ledi−
1,j)
Ci+1,j=max(0,1−
ledi+1,j)
Ci,j−
1=max(0,1−
ledi,j−
1)
Ci,j+1=max(0,1−
ledi,j+1)d) updating said backlight image driving values and the values of said neighbors, with the following equations;
ledi,j=1
ledi−
1,j=ledi−
1,j+k(ledi,j−
1)*Ci−
1,j/Σ
(Ci,j)
ledi+1,j=ledi+1,j+k(ledi,j−
1)*Ci−
1,j/Σ
(Ci,j)
ledi,j−
1=ledi,j−
1+k(ledi,j−
1)*Ci−
1,j/Σ
(Ci,j)
ledi,j+1=ledi,j+1+k(ledi,j−
1)*Ci−
1,j/Σ
(Ci,j);wherein k is a constant used to compensate for a reduced contribution from neighboring LEDs.
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8. A method for generating a backlight image for a display backlight array, said method comprising:
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a) receiving an input image comprising an array of pixel values representing an image at an LCD resolution; b) low-pass filtering said input image with a point spread function of a display diffusion screen to create a low-pass-filtered (LPF) image; c) subsampling said LPF image to an intermediate resolution thereby creating a LED1p image; d) low-pass filtering said input image with a kernel that is smaller than the kernel used to create said LPF image thereby creating a second low-pass-filtered (SLPF) image; e) dividing said SLPF image into blocks wherein each block corresponds to a display backlight LED element in said display backlight array with some overlap between array elements; f) determining a maximum value in each of said blocks of said SLPF image thereby creating LEDmax values in an LEDmax image; and g) creating an LED1 image comprising values based on one of a corresponding LEDmax image value and a corresponding LED1p image value. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A method for generating a backlight image for a display backlight array, said method comprising:
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a) receiving an input image comprising an array of pixel values representing an image at an LCD resolution; b) low-pass filtering said input image with a point spread function of a display diffusion screen to create a low-pass-filtered (LPF) image; c) subsampling said LPF image to an intermediate resolution thereby creating a LED1p image; d) low-pass filtering said input image with a kernel that is smaller than the kernel used to create said LPF image thereby creating a second low-pass-filtered (SLPF) image; e) dividing said SLPF image into blocks wherein each block corresponds to a display backlight LED element in said display backlight array with some overlap between array elements; f) determining a maximum value in each of said blocks of said SLPF image thereby creating LEDmax values in an LEDmax image; g) creating an LED1 image comprising values based on one of a corresponding LEDmax image value and a corresponding LED1p image value; h) establishing a target LED driving value (led0) image comprising virtual points located between pixel elements of said input image by convolving a target backlight image, BL0, with an LED mask comprising said virtual point locations; i) determining an approximated backlight image (bl1) by convolving said led0 image with a truncated point spread function (psf2) kernel; j) determining a backlight deficiency image (bl2), which represents a difference between said BL0 image and said bl1 image; k) creating a compensated LED driving value image (bl3) by convolving said bl0 image with a diffusion kernel; and l) determining a modified LED target value image (BL1) by adding said BL0 image to said bl3 image. - View Dependent Claims (17, 18, 19, 20)
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Specification