SYSTEMS AND METHODS FOR RENDERING A DISPLAY TO COMPENSATE FOR A VIEWER'S VISUAL IMPAIRMENT

• US 20130120390A1
• Filed: 06/10/2011
• Published: 05/16/2013
• Est. Priority Date: 06/11/2010
• Status: Active Grant

• Current Assignee: Back In Focus
• Original Assignee: Back In Focus
• Inventors: Marchand, Pierre, Pite, Eric, Guillemet, Herv, Trocme, Loic
• Granted Patent: US 9,852,496 B2
• Time in Patent Office: Days
• US Class Current: 345/428
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: G06T 5/80 Geometric correction
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2340/14 Solving problems related to the presentation of information to be displayed
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2380/08 Biomedical applications
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T

Abstract

A system and method is provided for rendering on a display of an electronic device a pre-corrected image of an original image to compensate for a visual impairment of a user of the device, such that the pre-corrected image when displayed on the display would be perceived by the user to be in better optical focus than the user would perceive a display of the original image. The method includes receiving hardware characteristics of the display, receiving at least one parameter describing the visual impairment of the user, receiving at least one parameter describing the conditions under which the display is seen by the user, calculating a pupil function, calculating a Point Spread Function (PSF), calculating a pre-corrected image corresponding to at least a portion of the original image to compensate for the visual impairment of the user, and rendering on the display the pre-corrected image.

Claims

1-29. -29. (canceled)

30. A computer-implemented method for rendering on a display of an electronic device a pre-corrected image of an original image to compensate for a second-order visual impairment of a user of the device such that the pre-corrected image when displayed on the display would be perceived by the user to be in better optical focus than the user would perceive a display of the original image, comprising:

receiving hardware characteristics of the display;

receiving at least one parameter describing the visual impairment of the user, wherein the parameter is at least one from the group consisting of;

a sphere parameter, a cylinder and axis parameters, and a near point of accommodation, or another mathematically-equivalent set of parameters representing the visual impairment of the user;

receiving at least one parameter describing the conditions under which the display is seen by the user;

calculating, using the at least one parameter describing the visual impairment of the user, a Point Spread Function (PSF), or another mathematically-equivalent representation of an imaging capability of an eye'"'"'s optical system including an optical transfer function (OTF);

calculating a pre-corrected image corresponding to at least a portion of the original image to compensate for the visual impairment of the user, using a constrained optimization technique that maximizes perceived quality of the pre-corrected image according to constraints determined by a set of images capable of being displayed according to the hardware characteristics, and

rendering on the display the pre-corrected image.

31. The computer-implemented method of claim 30, wherein receiving at least one parameter describing the visual impairment of the user comprises at least one of receiving the visual impairment parameter from a remote database, a local database, real-time input, or real-time estimation.

32. The computer-implemented method of claim 30, wherein receiving at least one parameter describing the conditions under which the display is seen by the user comprises at least one of receiving the display condition parameter from real-time estimation, real-time input, or a local database.

33. The computer-implemented method of claim 30, wherein receiving hardware characteristics of the display comprises receiving at least one from the group consisting of pixel dimensions and spacing, display width and height, display reflectivity emission spectra of each of a sub-pixel class, and a relationship between pixel value and luminance.

34. The computer-implemented method of claim 30, wherein receiving a parameter describing the conditions under which the display is seen comprises receiving one or more of a measurement of the distance between the eye of the user and the screen, an ambient luminosity, and a measurement of the pupil size of the user.

35. The computer-implemented method of claim 30, wherein rendering comprises pre-correction of text implemented as a rendering effect performed by a font rendering module of an operating system.

36. The computer-implemented method of claim 30, wherein calculating the PSF comprises calculating a polychromatic PSF per sub-pixel class of the display using an emission spectrum of the sub-pixel class and an average photopic spectral sensitivity function of the user'"'"'s retina, and

wherein rendering on the display the pre-corrected image comprises rendering the pre-corrected image for each sub-pixel class.

37. The computer-implemented method of claim 30, wherein calculating a pre-corrected image is performed using the constrained optimization technique employing a gradient descent or using a Van-Cittert algorithm.

38. The computer-implemented method of claim 30, wherein the constrained optimization technique is formulated based on a metric comprising a variation of sensitivity of eye receptors due to luminance.

39. The computer-implemented method of claim 30, wherein the constrained optimization technique is formulated based on an objective function representing an overall image quality as perceived by the user.

40. The computer-implemented method of claim 30, wherein at least one from the parameters describing the visual impairment of the user and the parameter describing the conditions under which the display is seen is determined by performing a dichotomy test, the dichotomy test comprising:

presenting to the user images pre-corrected using different hypotheses.

41. The computer-implemented method of claim 30, further comprising enabling or disabling rendering by striking a hard key, varying an option, shaking the device, or using an embedded camera to detect eyeglasses being worn by the user.

42. The computer-implemented method of claim 30, wherein the pre-correction is done using a PSF of the right eye only, a PSF of the left eye only, or a PSF resulting from a combination of both PSF'"'"'s of the left and right eyes, or both PSF'"'"'s of the left and right eyes and applying two pre-correction results to two elements of an autostereoscopic monitor.

43. A system for rendering on a display of an electronic device a pre-corrected image of an original image to compensate for a second-order visual impairment of a user of the device such that the pre-corrected image when displayed on the display would be perceived by the user to be in better optical focus than the user would perceive a display of the original image, comprising:

a computer processor; and

a memory connected to said computer processor, wherein the memory is configured with instructions to cause the processor to

(1) receive hardware characteristics of the display screen from a local database;

(2) receive a parameter describing the visual impairment of the user from at least one of a remote database, a local database, real-time input, or real-time estimation, wherein the parameter is at least one from the group consisting of;

a sphere parameter, a cylinder and axis parameters, and a near point of accommodation;

(3) receive a parameter describing a condition under which the display is seen by the user from at least one of real-time estimation, real-time input, or local database;

(4) calculate, using the parameter describing the visual impairment of the user, a Point Spread Function (PSF), or another mathematically-equivalent representation of an imaging capability of an eye'"'"'s optical system including an optical transfer function (OTF);

(5) calculate a pre-corrected image corresponding to at least a portion of the original image to compensate for the visual impairment of the user, using a constrained optimization technique that maximizes perceived quality of the pre-corrected image according to constraints determined by a set of images capable of being displayed according to the hardware characteristics; and

(6) render on the display the pre-corrected image.

44. A non-transitory computer readable storage medium storing a program configured for execution by a processor, the program when executed being adapted to cause the processor to:

receive a hardware characteristic of the display from a database;

receive a parameter describing a second order visual impairment of the user from a remote database, a local database, real-time input, or real-time estimation;

receive a parameter describing the conditions under which the display is seen by the user from at least one of real-time estimation, real-time input, or local database, wherein the parameter is at least one from the group consisting of;

a sphere parameter, a cylinder and axis parameters, and a near point of accommodation;

calculate, using the parameter describing the visual impairment of the user, a Point Spread Function (PSF), or another mathematically-equivalent representation of an imaging capability of an eye'"'"'s optical system, including an optical transfer function (OTF);

calculate a pre-corrected image corresponding to at least a portion of an original image to compensate for a user'"'"'s visual impairment, using a constrained optimization technique that maximizes perceived quality of the pre-corrected image according to constraints determined by a set of images capable of being displayed according to the hardware characteristics; and

render the pre-corrected image on a display of the electronic device, whereby the display of the pre-corrected image would be perceived by the user to be in better optical focus than the user would perceive a display of the original image.