Adjustment of monitor resolution and pixel refreshment based on detected viewer distance
Techniques are disclosed for improving energy efficiency of displays, and in particular, displays capable of selective refresh. In an embodiment, the techniques include adjusting the effective resolution of a display based on the viewer's distance from the display. The effective resolution adjustment can be accomplished by, for example, grouping individual pixels or blurring the display buffer (or both pixel grouping and blurring) based on the viewer's distance from the display. Such an adjustment has the effect of creating enlarged pixels from a plurality of smaller pixels. In any such cases, each of the enlarged pixels (also called macro-pixels) can then be selectively refreshed based on changes from the previous frame. In addition, even if one of the macro-pixels has changed from the last frame, it also need not be refreshed if the viewer would not perceive that change given a subtle or otherwise unperceivable difference in intensity.
1. A method for refreshing a display, comprising:
identifying the distance of a viewer from a selectively refreshable display having an array of pixels;
automatically adjusting an effective resolution of the display based on the distance using pixel grouping or blurring or both, to generate macro pixels based on a plurality of smaller pixels; and
selectively refreshing the macro pixels changed by the adjusting, based on a comparison of intensity of the macro pixels with respect to intensity of adjacent macro pixels, in the same frame.
2. The method of claim 1 , further comprising:
receiving a frame of content data to be rendered by the display; and
identifying pixel groups that have changed from the previous frame.
3. The method of claim 2 wherein selectively refreshing pixels changed by the adjusting based on their intensity difference with respect to intensity of neighboring pixels comprises:
selectively refreshing changed pixels and/or pixel groups based on their intensity, wherein in response to an intensity change of a given pixel group from one frame to the next frame being below a given threshold, that pixel group is not refreshed.
4. The method of claim 1 wherein the distance of the viewer from the display is determined automatically using input from a distance sensor.
5. The method of claim 4 wherein the distance sensor comprises at least one of a camera, an infrared distance sensor, and an ultrasonic sensor.
6. The method of claim 1 wherein the distance of the viewer from the display is determined based on user input or is within a given range.
7. The method of claim 1 , further comprising:
identifying a visual impairment of the viewer.
8. The method of claim 1 wherein the method is user-configurable with respect to at least one of: the method being activated or not; the distance of the viewer from the display user interface; and whether or not the viewer has a visual impairment.
9. The method of claim 1 wherein adjusting the effective display resolution uses pixel grouping such that each pixel group includes two or more pixels, and each individual pixel within a given group is set to the same color.
10. The method of claim 9 wherein the color of the pixels in the given group is an average of colors represented by individual pixels of the group before the adjusting.
11. The method of claim 9 wherein adjusting the effective display resolution further uses blurring so that neighboring pixel groups will appear more similar in intensity.
12. At least one non-transitory computer readable medium encoded with instructions that when executed by one or more processors cause a process to be carried out, the process comprising:
identify the distance of a viewer from a selectively refreshable display having an array of pixels;
automatically adjusting an effective resolution of the display based on the distance using pixel grouping or blurring or both, to generate macro pixels based on a plurality of smaller pixels; and
selectively refresh the macro pixels changed by the adjusting, based on a comparison of intensity of the macro pixels with respect to intensity of adjacent macro pixels, in the same frame.
13. The computer readable medium of claim 12 , the process further comprising:
receive a frame of content data to be rendered by the display;
identify pixel groups that have changed from the previous frame; and
selectively refresh changed pixels and/or pixel groups based on their intensity, wherein in response to an intensity change of a given pixel group from one frame to the next frame being below a given threshold, that pixel group is not refreshed.
14. The computer readable medium of claim 12 wherein the distance of the viewer from the display is determined automatically using input from a distance sensor.
15. The computer readable medium of claim 12 , the process further comprising:
identify a visual impairment of the viewer.
16. The computer readable medium of claim 12 , the process further comprising:
present a user interface configured to provide user-configurability with respect to at least one of: the process being activated or not; the distance of the viewer from the display user interface; and whether or not the viewer has a visual impairment.
17. The computer readable medium of claim 12 wherein adjusting the effective display resolution uses pixel grouping such that each pixel group includes two or more pixels, and each individual pixel within a given group is set to the same color, wherein the color of the pixels in the given group is a blend of colors represented by individual pixels of the group before the adjusting.
18. The computer readable medium of claim 17 wherein adjusting the effective display resolution further uses blurring so that neighboring pixel groups will appear more similar in intensity.
19. A system for refreshing a display, comprising:
a processor; and
a display driver at least one of executable and controllable at least in part by the processor and configured to, based on the distance of a viewer from a selectively refreshable display having an array of pixels:
automatically adjust an effective resolution of the display using pixel grouping or blurring or both, to generate macro pixels based on a plurality of smaller pixels, so that neighboring pixels will appear more similar in intensity; and
selectively refresh the macro pixels changed by the adjusting, based on a comparison of intensity of the macro pixels with respect to intensity of adjacent macro pixels, in the same frame.
20. The system of claim 19 wherein the system further includes at least one of:
a network interface operatively coupled to the processor;
the display operatively coupled to the processor;
a display buffer configured to receive a frame of content data to be rendered by the display; and
a distance sensor configured to indicate the distance of the viewer from the display;
wherein the display driver is configured to identify pixel groups that have changed from the previous frame, and to selectively refresh changed pixels and/or pixel groups based on their intensity, wherein in response to an intensity change of a given pixel group from one frame to the next frame being below a given threshold, that pixel group is not refreshed.
21. The system of claim 19 wherein the display driver is configured to adjust the effective display resolution using pixel grouping such that each pixel group includes two or more pixels, and each individual pixel within a given group is set to the same color, wherein the color of the pixels in the given group is a blend of colors represented by individual pixels of the group before the adjusting by the display driver.