Two-dimensional piecewise approximation to compress image warping fields

Abstract

Techniques to pre-warp an image based on an image warping map comprising a number of cells where each cell corresponds to a polynomial approximation for a number of corresponding pixels to be warped are described. An image warping map can be generated by partitioning a per pixel warping map into cells and approximating the pixel movements of each cell with a polynomial function.

What is claimed is: 
     
         1 . An apparatus, comprising:
 logic, at least a portion of which is implemented in hardware, the logic to:
 receive an image to be warped, the image comprising a plurality of pixels; 
 warp at least one of the plurality of pixels based in part on an image warping field, the image warping field comprising a plurality of cells, each of the plurality of cells comprising at least one warping coefficient to warp ones of the plurality of pixels; and 
 generate a pre-warped image based on the plurality of pixels warped based on the image warping field. 
   
     
     
         2 . The apparatus of  claim 1 , the logic to:
 retrieve the at least one warping coefficient for a first cell of the image warping field;   determine, for each of the plurality of pixels, ones of the plurality of pixels corresponding to the first cell; and   warp each of the ones of the plurality of pixels corresponding to the first cell based on the retrieved at least one warping coefficient.   
     
     
         3 . The apparatus of  claim 2 , the logic to:
 retrieve the at least one warping coefficient for a second cell of the image warping field;   determine, for each of the plurality of pixels, ones of the plurality of pixels corresponding to the second cell; and   warp each of the ones of the plurality of pixels corresponding to the second cell based on the retrieved at least one warping coefficient.   
     
     
         4 . The apparatus of  claim 1 , the at least one warping coefficient for each of the plurality of cells a coefficient for a polynomial function. 
     
     
         5 . The apparatus of  claim 4 , wherein the at least one coefficient for a first cell of the plurality of cells is different than the at least one coefficient for a second cell of the plurality of cells. 
     
     
         6 . The apparatus of  claim 4 , wherein each of the plurality of cells comprise a plurality of warping coefficients. 
     
     
         7 . The apparatus of  claim 4 , wherein each of the plurality of cells comprise between 2 and 10 warping coefficients. 
     
     
         8 . The apparatus of  claim 1 , wherein the image warping field is a first image warping field and the pre-warped image is a first pre-warped image, the logic to:
 warp each of the plurality of pixels based in part on a second image warping field, the second image warping field comprising a plurality of cells, each of the plurality of cells comprising at least one warping coefficient to warp the plurality of pixels; and   generate a second pre-warped image based on the plurality of pixels warped based on the second image warping field.   
     
     
         9 . The apparatus of  claim 1 , the logic comprising one or more registers to store the at least one warping coefficients. 
     
     
         10 . The apparatus of  claim 1 , the logic implemented in a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). 
     
     
         11 . A system comprising:
 a light source to emit light beams;   a reflector to reflect the light beams to project an image; and   logic, at least a portion of which is implemented in hardware, the logic to:
 receive a plurality of pixels corresponding to the image to be projected; 
 warp each of the plurality of pixels based in part on an image warping field, the image warping field comprising a plurality of cells, each of the plurality of cells comprising at least one warping coefficient to warp the plurality of pixels; and 
 send a control signal to the light source to cause the light source to emit the light beams corresponding to the plurality of pixels warped based on the image warping field. 
   
     
     
         12 . The system of  claim 11 , the logic to:
 retrieve the at least one warping coefficient for a first cell of the image warping field;   determine, for each of the plurality of pixels, ones of the plurality of pixels corresponding to the first cell; and   warp each of the ones of the plurality of pixels corresponding to the first cell based on the retrieved at least one warping coefficient.   
     
     
         13 . The system of  claim 12 , the logic to:
 retrieve the at least one warping coefficient for a second cell of the image warping field;   determine, for each of the plurality of pixels, ones of the plurality of pixels corresponding to the second cell; and   warp each of the ones of the plurality of pixels corresponding to the second cell based on the retrieved at least one warping coefficient.   
     
     
         14 . The system of  claim 11 , wherein the image warping field is a first image warping field, the light source is a first light source, the light beams are first light beams, the system comprising a second light source to emit second light beams, the logic to:
 warp each of the plurality of pixels based in part on a second image warping field, the second image warping field comprising a plurality of cells, each of the plurality of cells comprising at least one warping coefficient to warp the plurality of pixels; and   send a control signal to the second light source to cause the second light source to emit second light beams corresponding to the plurality of pixels warped based on the second image warping field.   
     
     
         15 . The system of  claim 11 , the light source comprising at least one of a laser or a light emitting diode (LED) and the reflector comprising a microelectromechanical system (MEMS) mirror. 
     
     
         16 . The system of  claim 15 , comprising a projection surface, the reflector to reflect the light beams across the projection surface to project the image. 
     
     
         17 . The system of  claim 16 , the projection surface comprising a holographic optical element to reflect the projected image as a virtual image. 
     
     
         18 . A method comprising:
 receiving an image to be warped, the image comprising a plurality of pixels;   warping each of the plurality of pixels based in part on an image warping field, the image warping field comprising a plurality of cells, each of the plurality of cells comprising at least one warping coefficient to warp ones of the plurality of pixels; and   generating a pre-warped image based on the plurality of pixels warped based on the image warping field.   
     
     
         19 . The method of  claim 18 , comprising:
 retrieving the at least one warping coefficient for a first cell of the image warping field;   determining, for each of the plurality of pixels, ones of the plurality of pixels corresponding to the first cell; and   warping each of the ones of the plurality of pixels corresponding to the first cell based on the retrieved at least one warping coefficient.   
     
     
         20 . The method of  claim 19 , comprising:
 retrieving the at least one warping coefficient for a second cell of the image warping field;   determining, for each of the plurality of pixels, ones of the plurality of pixels corresponding to the second cell; and   warping each of the ones of the plurality of pixels corresponding to the second cell based on the retrieved at least one warping coefficient.   
     
     
         21 . The method of  claim 20 , the at least one warping coefficient for each of the plurality of cells a coefficient for a polynomial function. 
     
     
         22 . The method of  claim 18 , wherein the image warping field is a first image warping field and the pre-warped image is a first pre-warped image, the method comprising:
 warping each of the plurality of pixels based in part on a second image warping field, the second image warping field comprising a plurality of cells, each of the plurality of cells comprising at least one warping coefficient to warp the plurality of pixels; and   generating a second pre-warped image based on the plurality of pixels warped based on the second image warping field.   
     
     
         23 . At least one machine-readable storage medium comprising instructions that when executed by a processing unit, cause the processing unit to:
 partition a per pixel image warping map into a plurality of cells, the per pixel image warping map comprising a plurality of pixel movements, the plurality of pixel movements corresponding to pixel in an image to be warped, each of the plurality of cells corresponding to at least one of the plurality of pixel movements; and   determine, for each cell, a polynomial approximation of the pixel movements corresponding to the cell.   
     
     
         24 . The at least one machine-readable storage medium of  claim 23 , comprising instructions that cause the processing unit to determine the polynomial approximation based on using a plurality of warping coefficients. 
     
     
         25 . The at least one machine-readable storage medium of  claim 24 , comprising instructions that cause the processing unit to determine the polynomial approximation based in part on application of a linear regression to the pixel movements.