Method and apparatus for re-sizing and zooming images by operating directly on their digital transforms

• US 6,456,745 B1
• Filed: 09/16/1998
• Issued: 09/24/2002
• Est. Priority Date: 09/16/1998
• Status: Expired due to Term

• Current Assignee: Intellectual Discovery Co., Ltd.
• Original Assignee: Push Entertainment, Inc.
• Inventors: Bruton, Leonard Thomas, Simpson, Todd, Yee, Barry
• Primary Examiner(s): Couso, Jose L.
• Assistant Examiner(s): PATEL, KANJIBHAI B
• Application Number:
  US09/154,227
• Time in Patent Office: 1,469 Days
• Field of Search: 382/298, 382/250, 382/232, 382/233, 382/240, 382/282, 382/248, 382/300, 382/294, 382/276, 345/127, 345/667, 345/163, 345/347, 348/93
• US Class Current: 382/298
• CPC Class Codes: G06T 3/4084 in the transform domain, e.g. fast Fourier transform [FFT] domain scaling

Abstract

Digital images are represented in the spatial domain by numbers that correspond to pixels and may be transformed to a transform domain image by means of a Transform Method. Other Transform Methods are used to transform the transform domain image back to the original spatial domain image. In this invention, these other Transform Methods are modified in such a way that the Modified Transform Method yields spatial domain images that are re-sized versions of the original spatial domain image. Methods are disclosed for employing the Modified Transform Method to implement zoomed and panned versions of the re-sized images. The re-sized images do not require pixel-level smoothing filters and other methods for removing image distortions due to re-sizing.

Claims

1. A system for displaying multiple images comprising:

means for displaying an image;

means for selecting a portion of said displayed image; and

means for concurrently displaying, on said display means, the image and the selected portion, wherein said selected portion is modified using a Modified Transform Method, wherein said Modified Transform Method is associated with transforming a transform domain image to a spatial domain image and includes a plurality of synthetic data points.

2. The system of claim 1, wherein said means for selecting a portion of the image comprises:

a television remote control.

3. The system of claim 1, wherein said means for selecting a portion of the image comprises:

a computer pointing device.

4. The system of claim 1, wherein said modified selected portion has been resized using said Modified Transform Method.

5. The system of claim 1, wherein said displayed selected portion has been panned using said Modified Transform Method.

6. The system of claim 1, wherein said displayed selected portion has been zoomed-in using said Modified Transform Method.

7. The system of claim 3, wherein said displayed selected portion has been zoomed-out using said Modified Transform Method.

8. A method of modifying a digital image by array operations, wherein the digital image is represented by data stored in a first array having N columns and M rows as spatial domain information, wherein said digital image is to be scaled by a scaling factor s₁ in the horizontal direction and by a scaling factor s₂ in the vertical direction, comprising the steps of:

transforming data in the first array to a frequency domain via a first array operation to produce a second array, wherein said first array operation includes utilizing basis functions of the form b(k₁, k₂, n₁, n₂), wherein k₁ and k₂ are elements of the frequency domain, and wherein n₁ and n₂ are elements of the spatial domain;

modifying the second array to produce a third array having X columns and Y rows as frequency domain information, wherein at least one of the following conditions are met;

X≠

N and Y≠

M, and wherein scaling of the digital image does not occur in the modifying step; and

transforming data in the third array into spatial domain information via a modified array operation, said modified array operation being associated with basis functions of the form b(k₁/s₁, k₂/s₂, n₁, n₂), and wherein the modified array operation is not the inverse of the first array operation.

9. The method of claim 8 wherein said step of modifying includes adding synthetic data points to the second array.

10. The method of claim 8 wherein said step of transforming data in the third array produces a fourth array, said method further comprising the step of:

cropping data in the fourth array when at least one of s₁ and s₂ is less than one.

11. The method of claim 8 wherein at least one of the following conditions need not be met by said modifying:

X=s₁N and Y=s₂M.

12. A system for modifying a digital image by array operations, wherein the digital image is represented by data stored in a first array having N columns and M rows as spatial domain information, wherein said digital image is to be scaled by a scaling factor s₁ in the horizontal direction and by a scaling factor s₂ in the vertical direction, comprising the steps of:

means for transforming data in the first array to a frequency domain via a first array operation to produce a second array, wherein said first array operation includes utilizing basis functions of the form b(k₁, k₂, n₁, n₂), wherein k₁ and k₂ are elements of the frequency domain, and wherein n₁ and n₂ are elements of the spatial domain;

means for modifying the second array to produce a third array having X columns and Y rows as frequency domain information, wherein at least one of the following conditions are met;

X≠

N and Y≠

M, and wherein scaling does not occur in the modifying step; and

means for transforming data in the third array into spatial domain information via a modified array operation, said modified array operation being associated with basis functions of the form b(k₁/s₁, k₂/s₂, n₁, n₂), and wherein the modified array operation is not the inverse of the first array operation.

13. The system of claim 12 wherein said means for modifying includes adding synthetic data points to the second array.

14. The system of claim 12 wherein said means for transforming data in the third array produces a fourth array, said system further comprising:

means for cropping data in the fourth array, wherein said means for cropping operates when at least one of s₁ and s₂ is less than one.

15. The system of claim 12 wherein at least one of the following conditions is met:

the value of X is greater than s₁N and the value of Y is greater than s₂M.