Image generation with interpolation of pixels on a grid to pixels on a scan trajectory

• US 8,274,522 B2
• Filed: 12/01/2010
• Issued: 09/25/2012
• Est. Priority Date: 05/19/2003
• Status: Expired due to Term

• Current Assignee: Microvision, Inc.
• Original Assignee: Microvision, Inc.
• Inventors: Brown, Margaret K., Freeman, Mark O., Champion, Mark, Linden, Kelly D., Raghavan, Aarti, Swilley, Shawn M.
• Primary Examiner(s): Hsu, Joni
• Application Number:
  US12/957,577
• Publication Number:
  US 20110069084A1
• Time in Patent Office: 664 Days
• Field of Search: 345/530, 345/536, 345/537, 345/545, 345/560, 345/647, 345/649
• US Class Current: 345/560
• CPC Class Codes: G02B 26/0816 by means of one or more reflecting elements
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/02 by tracing or scanning a light beam on a screen
• CPC Class Codes: G09G 3/025 with scanning or deflecting the beams in two directions or dimensions
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/022 using memory planes
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 19/86 involving reduction of coding artifacts, e.g. of blockiness
• CPC Class Codes: H04N 3/08 having a moving reflector
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

An image generation apparatus provides interpolation and distortion correction. The interpolation and distortion correction may be provided in one or two dimensions. Nonlinear image scan trajectories, such as sinusoidal and bi-sinusoidal trajectories are accommodated. Horizontal and vertical scan positions are determined using a linear pixel clock, and displayed pixel intensities are determined using interpolation techniques.

Claims

1. An image generation apparatus comprising:

a frame buffer to hold a plurality of rows of pixel data corresponding to a grid of pixels;

a row buffer coupled to the frame buffer to receive a current row of the plurality of rows of pixel data;

a horizontal scan position determination component to periodically determine a horizontal scan position of a scan trajectory that does not intersect every pixel on the grid, wherein the horizontal scan position determination component is operable to determine the horizontal scan position as a sine of an increasing angle plus a phase offset that is a function of color and vertical scan position; and

an interpolation component coupled to receive pixel data from the row buffer and operable to interpolate between pixel data on either side of the horizontal scan position in the current row to create new display pixel values that do not fall on the grid.

2. The image generation apparatus of claim 1 further comprising a vertical scan position determination component operable to approximate a vertical scan position of the scan trajectory as a different row for each horizontal sweep of the scan trajectory.

3. The image generation apparatus of claim 1 wherein the horizontal scan position determination component is operable to determine the horizontal scan position as (a sine of an increasing angle) times a multiplier.

4. An image generation apparatus comprising:

a frame buffer to hold a plurality of rows of pixel data corresponding to a grid of pixels;

a horizontal scan position determination component to periodically determine a horizontal scan position of a scan trajectory as (the sine of an increasing angle) times a multiplier, wherein the multiplier is a function of a vertical scan position; and

an interpolation component coupled to receive pixel data from the frame buffer and operable to interpolate between pixel data on either side of the horizontal scan position to determine display pixel values for points not on the grid.

5. The image generation apparatus of claim 4 further comprising a vertical scan position determination component operable to approximate a vertical scan position of the scan trajectory as one row for each horizontal sweep of the scan trajectory.

6. The image generation apparatus of claim 5 wherein the interpolation component is operable to interpolate between pixel data in the one row.

7. The image generation apparatus of claim 5 wherein the interpolation component is further operable to interpolate between pixel data on either side of the vertical scan position.

8. An image generation apparatus comprising:

a frame buffer to hold a plurality of rows of pixel data corresponding to a grid of pixels;

a horizontal scan position determination component to periodically determine a horizontal scan position of a scan trajectory as (the sine of an increasing angle) plus an offset, wherein the offset is a function of a vertical scan position; and

an interpolation component coupled to receive pixel data from the frame buffer and operable to interpolate between pixel data on either side of the horizontal scan position to determine display pixel values for points not on the grid.

9. The image generation apparatus of claim 8 further comprising a vertical scan position determination component operable to approximate a vertical scan position of the scan trajectory as one row for each horizontal sweep of the scan trajectory.

10. The image generation apparatus of claim 9 wherein the interpolation component is operable to interpolate between pixel data in the one row.

11. The image generation apparatus of claim 9 wherein the interpolation component is further operable to interpolate between pixel data on either side of the position.

12. An image generation apparatus comprising:

an image warping and interpolation component having a number of rows and columns corresponding to a first resolution, the image warping and interpolation component operable to warp an image in response to a set of parameterized basis distortions;

a frame buffer to hold rows of pixel data resulting from the image warping and interpolation component;

a horizontal scan position determination component to periodically determine a horizontal scan position of a sinusoidal scan trajectory as (the sine of an increasing angle) plus an offset, wherein the offset is a function of a color;

a vertical scan position determination component to periodically determine a vertical scan position of the scan trajectory; and

an interpolation component coupled to receive pixel data from the frame buffer and operable to interpolate between pixel values on either side of the horizontal scan position and on either side of the vertical scan position to create an image with a resolution higher than the first resolution.

13. The image generation apparatus of claim 12 wherein the set of parameterized basis distortions are operable to pre-warp an image for display on a non-uniform surface.

14. The image generation apparatus of claim 12 wherein the set of parameterized basis distortions are operable to pre-warp an image for a head-up display.

15. A mobile device comprising:

a laser projector to project an image, the laser projector including an image generation apparatus having a frame buffer to hold a plurality of rows of pixel data corresponding to a grid of pixels, a row buffer coupled to the frame buffer to receive more than one but fewer than all of the plurality of rows of pixel data, a horizontal scan position determination component to periodically determine a horizontal scan position of a scan trajectory as (the sine of an increasing angle) plus an offset, wherein the offset is a function of a vertical scan position, and an interpolation component coupled to receive pixel data from the row buffer and operable to interpolate between pixel data on either side of the horizontal scan position to determine display pixel values for display pixels that do not correspond in position to pixels in the grid.

16. The mobile device of claim 15 further comprising a memory card slot.

17. The mobile device of claim 15 further comprising a communications receiver.

18. The mobile device of claim 15 further comprising a communications transceiver.

19. The mobile device of claim 18 wherein the communications transceiver is operable to communicate using cellular telephone signals.

20. A method comprising:

determining a horizontal scan position of a light beam scan trajectory of an image generation apparatus as the sum of an offset and a scaled sine of an increasing angle, wherein the offset is a function of color;

horizontally interpolating between source image pixel data to the left and right of the horizontal scan position to determine a pixel intensity of a new pixel at the horizontal scan position, wherein the new pixel at the horizontal scan position does not correspond in position to pixels in the source image; and

modulating a laser diode to display the new pixel at the horizontal scan position.

21. The method of claim 20 further comprising:

determining a vertical scan position of the scan trajectory; and

vertically interpolating between pixel data above and below the vertical scan position; and

combining the horizontal and vertical interpolation to arrive at the pixel intensity of the new pixel at an intersection of the horizontal scan position and the vertical scan position.

22. The method of claim 20 wherein determining a horizontal scan position comprises scaling the sine with a multiplier that is a function of color.

23. The method of claim 20 wherein determining a horizontal scan position comprises scaling the sine with a multiplier that is a function of vertical scan position.