Digital image warping system

• US 6,636,216 B1
• Filed: 07/10/1998
• Issued: 10/21/2003
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Google Inc. (Alphabet Inc.)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Lapstun, Paul, Silverbrook, Kia
• Primary Examiner(s): Padmanabhan, Mano
• Application Number:
  US09/113,224
• Time in Patent Office: 1,929 Days
• Field of Search: 345/419, 345/619, 345/955, 345/646, 345/647, 345/427, 345/660, 382/215, 382/209, 382/308
• US Class Current: 345/427
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2129 Authenticate client device independently of the user
• CPC Class Codes: G06T 15/20 Perspective computation
• CPC Class Codes: H04N 1/0044 for image preview or review, e.g. to help the user position a sheet
• CPC Class Codes: H04N 1/2112 using still video cameras
• CPC Class Codes: H04N 1/2154 the still video camera incorporating a hardcopy reproducing device, e.g. a printer
• CPC Class Codes: H04N 2101/00 Still video cameras
• CPC Class Codes: H04N 23/00 Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 23/95 Computational photography systems, e.g. light-field imaging systems
• CPC Class Codes: H04N 5/2628 Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

Method and apparatus for producing a warped image from an input image. Image warp data encoded as an image on a card is read by a data reader in a camera. Each element of the warp map maps a corresponding region in an input image to a pixel location of the output image. The warp map is scaled to the dimensions of the output image so as to produce a scaled warp map, then each element in the scaled warp map is used to determine a contribution region in the input image by using a value corresponding to that element and values corresponding to adjacent elements. An output image color for a pixel of the output image that corresponds to the element of the contribution region is then produced.

Claims

1. A method of producing a warped image from an input image, said method comprising the steps of:

reading program data encoded as an image on a card by means of a data reader including a linear image sensor, the data defining a warp map for an output image having predetermined dimensions A×

B, each element of said warp map mapping a corresponding region in an input image to a pixel location of said output image, which corresponds to the co-ordinate location of said element within said warp map;

scaling said warp map to the dimensions of said output image so as to produce a scaled warp map;

for substantially each element in said scaled warp map, determining a contribution region in said input image by using a value corresponding to said element and values corresponding to adjacent elements; and

determining an output image colour for a pixel of said output image that corresponds to said element from said contribution region.

2. A method as claimed in claim 1, which includes storing said input image in the form of an image pyramid and determining the contribution region by interpolating between levels of said image pyramid.

3. A method as claimed in claim 2, wherein said interpolation between levels comprises linear interpolation.

4. A method as claimed in claim 1, wherein said warp map is stored in independent dimensional co-ordinates as separate channels.

5. A method as claimed in claim 1, wherein said contribution region is calculated utilizing a maximum span between adjacent elements in said scaled warp map.

6. A method as claimed in claim 1, wherein the program data is encoded according to Reed-Solomon coding.

7. A method as claimed in claim 1, wherein said scaled warp map is produced through bilinear interpolation of said warp map.

8. An apparatus for warping an input image to produce a warped output image, the apparatus comprising:

image input means for inputting an input image into said apparatus;

a data reader including a linear image sensor capable of reading program data encoded as an image on a card, the data defining a warp map consisting of an array of values, each value mapping a region in the input image;

means for scaling said warp map to the dimensions of an output image;

means for determining a corresponding region in said input image for each element in the warp map;

means for determining and outputting a colour from said corresponding region for each pixel in the output image.

9. A method of producing a warped image from an input image, the method comprising the steps of:

reading program data encoded as an image on a card by means of a data reader including a linear image sensor, the data defining a program which is operable on an input image to produce a desired warped image;

storing the program data in an on board memory;

sensing the input image and generating input image data representing said input image; and

applying the program to the input image data to generate an output image in the form of the desired warped image.

10. A method as claimed in claim 9, which includes the step of transforming data representing the input image into data representing an image pyramid.

11. A method as claimed in claim 10, which includes applying a function of the Vark language to the data representing the input image to transform the data into data representing the image pyramid.

12. An apparatus for producing a warped image from an input image, the apparatus including:

a data reader including a linear image sensor which is capable of reading and generating program data encoded as an image on a card;

an on board memory connected to the data reader to store the program data generated by the data reader;

an image sensor for sensing an input image to be warped, the image sensor being capable of generating input image data representing the sensed image;

a processor which is configured to apply the program data to the input image data and to generate output image data representing a desired warped image; and

an output image generator which is connected to the processor to generate an output image based on the output image data.

13. An apparatus as claimed in claim 12, in which the data reader is in the form of a card reader which is capable of reading data from any one of a number of different cards each carrying different forms of the program data.

14. An apparatus as claimed in claim 13, in which the card reader is configured to be capable of reading data from a card carrying data which is encoded with the Reed-Solomon technique.

15. An apparatus as claimed in claim 12, in which the on board memory is in the form of a suitable random access memory such as that known as DRAM.

16. An apparatus as claimed in claim 12, in which the image sensor is selected from one of a charge coupled device and an active pixel sensor.

17. An apparatus as claimed in claim 12, in which the processor includes a RISC CPU core which is configured to run the Vark image processing language.