Arbitrary fractional pixel movement

• US 8,098,262 B2
• Filed: 09/05/2008
• Issued: 01/17/2012
• Est. Priority Date: 09/05/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Lindahl, Aram, Ünsal, Martin
• Primary Examiner(s): Sajous, Wesner
• Application Number:
  US12/205,567
• Publication Number:
  US 20100060646A1
• Time in Patent Office: 1,229 Days
• Field of Search: 345/418, 345/428, 345/581, 345/586, 345/589, 345/606, 345616-618, 345640-643, 345/473, 345/502, 345/501, 345/506, 348/254, 348/552, 348/553, 348/671, 382/162, 382/167, 382/274, 382/276, 382299-300, 382/303, 382/305
• US Class Current: 345/613
• CPC Class Codes: G06T 13/80 2D [Two Dimensional] animation, e.g. using sprites

Abstract

A technique is provided for displaying pixels of an image at arbitrary subpixel positions. In accordance with aspects of this technique, interpolated intensity values for the pixels of the image are derived based on the arbitrary subpixel location and an intensity distribution or profile. Reference to the intensity distribution provides appropriate multipliers for the source image. Based on these multipliers, the image may be rendered at respective physical pixel locations such that the pixel intensities are summed with each rendering, resulting in a destination image having suitable interpolated pixel intensities for the arbitrary subpixel position.

Claims

1. A processor-implemented method for animating an image, comprising:

using a processor of an electronic device, determining a plurality of multipliers for an image at an initial location using one or more distributions, wherein each distribution is centered on a non-integer pixel location with respect to a display of the electronic device; and

using the processor of the electronic device, rendering, on the display of the electronic device, the image at the initial location and at proximate locations such that overlapping pixels of the rendered images have a cumulative intensity, wherein each rendering of the image is reduced in intensity by a respective multiplier of the plurality of multipliers.

2. The processor-implemented method of claim 1, comprising wherein the plurality of multipliers represent locations on a single distribution or the product of locations on two different distributions.

3. The processor-implemented method of claim 1, wherein the one or more distributions span three, five, or seven pixels.

4. The processor-implemented method of claim 1, comprising setting the pixel intensity values to 0 prior to rendering the image.

5. The processor-implemented method of claim 1, wherein the cumulative intensity corresponds to a grayscale intensity or an intensity at one or more color channels.

6. One or more non-transitory recording media, comprising computer-executable code configured to:

set pixel values to zero within a region of a display;

derive a plurality of intensity coefficients for an image based on a non-integer pixel position within the region;

render an image at multiple proximate positions to the non-integer pixel position in an additive manner, wherein each rendering of the image is performed using a respective one of the plurality of intensity coefficients.

7. The one or more non-transitory recording media of claim 6, wherein the computer-executable code configured to derive the plurality of intensity coefficients utilizes one or more intensity distributions describing pixel intensity as a function of the non-integer pixel position.

8. The one or more non-transitory recording media of claim 6, wherein the computer-executable code configured to render achieves an additive effect by assigning opacity to a source image being rendered while not assigning translucency to a destination image such that the intensities of the source and destination images are added at each pixel.

9. The one or more non-transitory recording media of claim 6, wherein the multiple proximate positions correspond to an initial pixel location and adjacent pixels in one or two-dimensions.

10. The one or more non-transitory recording media of claim 6, wherein the non-transitory media comprises a memory, a storage, or a expansion card of an electronic device.

11. An electronic device, comprising:

a display;

a storage device physically encoding routines for deriving intensity coefficients for arbitrary pixel locations and for animating an image using the derived intensity coefficients; and

one or more processors or graphics processing units (GPUs) configured to execute the routines stored in the storage device.

12. The electronic device of claim 11, wherein the electronic device comprises one of a media player, a cellular phone, or a personal data organizer.

13. The electronic device of claim 11, wherein the electronic device comprises a portable electronic device.

14. The electronic device of claim 11, wherein the routine for deriving intensity coefficients utilizes one or more intensity distributions, wherein each intensity distribution is centered on the arbitrary pixel location in at least one dimension.

15. The electronic device of claim 11, wherein the routine for animating the image renders the image at multiple locations adjacent to the arbitrary pixel location in an additive manner.

16. The electronic device of claim 11, wherein the storage device further physically encodes a routine for setting the intensity of one or more pixels where the image will be animated to zero.

17. A processor-implemented animation, comprising:

one or more animation steps implemented by a processor of an electronic device and displayed on a display of the electronic device, wherein the one or more animation steps are each perceived to occur at arbitrary subpixel locations, wherein each animation step that is perceived to occur at an arbitrary subpixel location comprises a plurality of proximate and additive renderings of an image, each rendering being modified by a respective intensity coefficient.

18. The processor-implemented animation of claim 17, wherein the respective intensity coefficients correspond to intercepts on a respective distribution centered about the respective arbitrary subpixel location.

19. A processor-implemented method, comprising:

using a processor of an electronic device, calculating a destination pixel intensity to be displayed on a display of the electronic device, wherein the destination pixel intensity is calculated in accordance with the equation;

D_(x,y)=0+(α

₁)(β

₁)(S<sub>(x−

1,y−

1)</sub>)+(α

₁)(β

₃)(S<sub>(x−

1,y+1)</sub>+(α

₂)(β

₁)(S<sub>(x,y−

1)</sub>)+(α

₂)(β

₂)(S_(x,y))+(α

₂(β

₃)(S_(x,y+1)+(α

₃)(β

₃)(S<sub>(x+1,y−

1)</sub>)+(α

₃)(β

₂)(S_(x+1,y))+(α

₃)(β

₃)(S_(x+1,y+1))

where D is the destination pixel intensity, S is a source pixel intensity, α

is an intensity coefficient derived with respect to a non-integer X-axis location, and β

is an intensity coefficient derived with respect to a non-integer Y-axis location.

20. The processor-implemented method of claim 19, wherein the equation is simplified to:

D_(x,y)=0+(α

₁)(S<sub>(x−

1,y)</sub>)+(α

₂)(S_(x,y))+(α

₃)(S_(x+1,y)) for use in one-dimension.

21. The processor-implemented method of claim 19, wherein the pixel intensities correspond to a grayscale intensity or one or more color channel intensities.