Systems and methods for rendering a display to compensate for a viewer's visual impairment

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, directly 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,
• wherein rendering on the display the pre-corrected image comprises a separate pre-correction of text elements of the original image implemented as a rendering effect performed by a font rendering module of an operating system, separate from correction to non-text elements of the original image.

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, 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;
• 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;
• calculate, directly 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,
• wherein rendering the pre-corrected image on the display comprises a separate pre-correction of text elements of the original image implemented as a rendering effect performed by a font rendering module of an operating system, separate from correction to non-text elements of the original image.