Method and apparatus for color-preserving spectrum reshape

• US 10,600,213 B2
• Filed: 02/24/2017
• Issued: 03/24/2020
• Est. Priority Date: 02/27/2016
• Status: Active Grant

• Current Assignee: Focal Sharp Inc.
• Original Assignee: Focal Sharp Inc.
• Inventors: Shih, Kuang-Tsu
• Primary Examiner(s): Faulk, Devona E
• Assistant Examiner(s): Beard, Charles L
• Application Number:
  US15/441,614
• Publication Number:
  US 20170249755A1
• Time in Patent Office: 1,124 Days
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 2380/08 Biomedical applications
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607

Abstract

A system include an light emitter to generate a primary light, a filter to filter the primary light to substantially remove a spectrum energy in a wavelength band, a display device to present visual content using the filtered primary light, and a processing device to receive a visual content, calculate, in view of the filtered primary light, a metamer of the visual content, and provide, to the display device, the metamer of the visual content to display in view of the filtered light.

Claims

1. A system, comprising:

a light emitter to generate a primary light comprising at least three primary colors;

an optical light blocker, wherein the optical blocker is to optically filter the primary light to remove a substantial portion of spectrum energy within a wavelength band corresponding to a color of the primary light and to substantially preserve the spectrum energy outside the wavelength band;

a display device to present a visual content using the optically filtered primary light; and

a processing device to;

receive the visual content;

calculate, taking into account an effect of the optically filtered primary light on color appearance, a metamer of the visual content to compensate for the effect of the optically filtered primary light, wherein the calculated metamer when presented on the display device substantially preserves color appearance of the visual content rendered on the display device and substantially preserves hue of the visual content by means of digital image processing that compensates for the effect of the optically filtered primary light on the color appearance, and wherein taking into account an effect of the optically filtered primary light on color appearance comprises taking into account of a spectral sensitivity profile associated with retina cells, an emission spectrum associated with a pixel, and a spectral transmittance function corresponding to the color of the primary light; and

provide, to the display device, the metamer of the visual content to display using the optically filtered light.

2. The system of claim 1, wherein the optical light blocker is to remove the substantial portion of the spectrum energy within a wavelength band between 400 nanometer (nm) and 700 nm.

3. The system of claim 1, wherein the display device comprises at least one of a liquid crystal display (LCD) panel, a light-emitting diode display (LED) panel, or an organic light-emitting diode display (OLED) panel.

4. The system of claim 1, wherein the optical light blocker comprises glass coated with a chemical agent, and wherein the optical light blocker is to remove the substantial portion of the spectrum energy within the wavelength band and maximize a display gamut volume associated with the display device in view of the optically filtered primary light.

5. The system of claim 4, wherein to calculate the metamer, the processing device is further to:

determine, in view of the optically filtered primary light, whether a first pixel of the visual content is within the display gamut volume;

responsive to determining that the first pixel is outside the display gamut volume,

identify a second pixel within the display gamut volume, wherein the second pixel comprises an identical hue value and an identical saturation value as the first pixel but a scaled lightness value of the first pixel; and

replace the first pixel with the second pixel.

6. The system of claim 5, wherein to calculate the metamer, the processing device is further to:

apply one of an edge-preserving filter or a low-pass filter to a scale factor map comprising a plurality of scale factors to generate a second scale factor; and

use the second scale factor to scale a lightness value of the first pixel.

7. The system of claim 1, wherein calculation of the metamer preserves a white point of the display device.

8. The system of claim 1, wherein the optical light blocker is further to substantially remove the spectrum energy in a second wavelength band.

9. The system of claim 1, wherein the optical light blocker is designed to maximize a display gamut associated with the display device while minimizing the spectrum energy within the wavelength band of the color received by the retina cells using an optimization solver.

10. The System of claim 9, wherein the optimization solver is a gradient descent solver.

11. A method comprising:

receiving, by a processing device, a visual content to be displayed on a display device;

applying an optical light blocker, wherein the optical blocker is to optically filter a primary light comprising at least three primary colors, emitted from a light source associated with the display device, to remove a substantial portion of spectrum energy within a wavelength band corresponding to a color of the primary light and to substantially preserve the spectrum energy outside the wavelength band;

calculating, taking into account an effect of the optically filtered primary light on color appearance, a metamer of the visual content to compensate for the effect of the optically filtered primary light, wherein the calculated metamer when presented on the display device substantially preserves color appearance of the visual content rendered on the display device and substantially preserves hue of the visual content by means of digital image processing that compensates for the effect of the optically filtered primary light on the color appearance, and wherein taking into account an effect of the optically filtered primary light on color appearance comprises taking into account of a spectral sensitivity profile associated with retina cells, an emission spectrum associated with a pixel, and a spectral transmittance function corresponding to the color of the primary light; and

providing, to the display device, the metamer of the visual content to display using the optically filtered light.

12. The method of claim 11, wherein to optically filter the primary light is to remove the substantial portion of the spectrum energy within a wavelength band between 400 nanometer (nm) and 700 nm.

13. The method of claim 11, wherein the display device comprises at least one of a liquid crystal display (LCD) panel, a light-emitting diode display (LED) panel, or an organic light-emitting diode display (OLED) panel.

14. The method of claim 11, wherein to optically filter the primary light is to remove the substantial portion of the spectrum energy within the wavelength band and maximize a display gamut volume associated with the display device in view of the optically filtered primary light.

15. The method of claim 14, wherein the calculating the metamer further comprises:

determining, in view of the optically filtered primary light, whether a first pixel of the visual content is within the display gamut volume;

responsive to determining that the first pixel is outside the display gamut volume, identifying a second pixel within the display gamut volume, wherein the second pixel comprises an identical hue value and an identical saturation value as the first pixel but a scaled lightness value of the first pixel; and

replacing the first pixel with the second pixel.

16. The method of claim 15, wherein the calculating the metamer further comprises:

applying one of an edge-preserving filter or a low-pass filter to a scale factor map comprising a plurality of scale factors to generate a second scale factor; and

using the second scale factor to scale a lightness value of the first pixel.

17. The method of claim 11, wherein calculation of the metamer preserves a white point of the display device.

18. A non-transitory machine-readable storage medium storing instructions which, when executed, cause a processing device to perform operations comprising:

receiving, by the processing device, a visual content to be displayed on a display device, wherein the display device is associated with a primary light comprising at least three primary colors, wherein the primary light is optically filtered by an optical light blocker, and wherein the optical blocker is to remove a substantial portion of a spectrum energy within a wavelength band corresponding to a color of the primary light and to substantially preserve the spectrum energy outside the wavelength band;

calculating, taking into account an effect of the optically filtered primary light on color appearance, a metamer of the visual content to compensate for the effect of the optically filtered primary light, wherein the calculated metamer when presented on the display device substantially preserves color appearance of the visual content rendered on the display device and substantially preserves hue of the visual content by means of digital image processing that compensates for the effect of the optically filtered primary light on the color appearance, and wherein taking into account an effect of the optically filtered primary light on color appearance comprises taking into account of a spectral sensitivity profile associated with retina cells, an emission spectrum associated with a pixel, and a spectral transmittance function corresponding to the color of the primary light; and

providing, to the display device, the metamer of the visual content to display using the optically filtered light.

19. The non-transitory machine-readable storage medium of claim 18, wherein the primary light is optically filtered to remove the substantial portion of the spectrum energy within a wavelength band between 400 nanometer (nm) and 700 nm.

20. The non-transitory machine-readable storage medium of claim 18, wherein the display device comprises at least one of a liquid crystal display (LCD) panel, a light-emitting diode display (LED) panel, or an organic light-emitting diode display (OLED) panel.

21. The non-transitory machine-readable storage medium of claim 18, wherein the primary light is filtered to remove the substantial portion of the spectrum energy within the wavelength band and maximize a display gamut volume associated with the display device in view of the optically filtered primary light.

22. The non-transitory machine-readable storage medium of claim 21, wherein the calculating the metamer further comprises:

determining, in view of the optically filtered primary light, whether a first pixel of the visual content is within the display gamut volume;

responsive to determining that the first pixel is outside the display gamut volume, identifying a second pixel within the display gamut volume, wherein the second pixel comprises an identical hue value and an identical saturation value as the first pixel but a scaled lightness value of the first pixel; and

replacing the first pixel with the second pixel.