METHOD AND APPARATUS FOR ADJUSTING PIXEL VALUES

• US 20090033689A1
• Filed: 01/08/2008
• Published: 02/05/2009
• Est. Priority Date: 08/03/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Avkarogullari, Gokhan, Bull, William E., Huang, Szu-Wen
• Granted Patent: US 8,576,247 B2
• Time in Patent Office: Days
• US Class Current: 345/698
• CPC Class Codes: G06T 15/503 Blending, e.g. for anti-aliasing
• CPC Class Codes: G09G 2340/10 Mixing of images, i.e. displayed pixel being the result of an operation, e.g. adding, on the corresponding input pixels
• CPC Class Codes: G09G 5/14 Display of multiple viewports

Abstract

A system that adjusts pixel values to produce visual effects in a frame to be displayed is presented. During operation, the system receives coordinates and pixel-adjustment values for one or more control points within the frame. Next, the system calculates pixel-adjustment values for pixels in the frame based on the coordinates and the pixel-adjustment values for the one or more control points. The system then applies the pixel-adjustment values to the pixels within the frame and displays the frame.

Claims

1. A method for adjusting pixel values within a frame to be displayed, comprising:

receiving coordinates and pixel-adjustment values for one or more control points within the frame;

calculating pixel-adjustment values for pixels in the frame based on the coordinates and the pixel-adjustment values for the one or more control points;

applying the pixel-adjustment values to the pixels within the frame; and

displaying the frame.

2. The method of claim 1, wherein calculating pixel-adjustment values for the frame involves:

for each degree-of-freedom within the frame, interpolating pixel-adjustment values for the pixels between the one or more control points; and

for each pixel, applying a function to the interpolated pixel-adjustment values for each degree-of-freedom to generate a pixel-adjustment value for the pixel.

3. The method of claim 2, wherein interpolating the pixel-adjustment values involves using one or more of:

a linear interpolation technique;

a polynomial interpolation technique; and

a spline interpolation technique.

4. The method of claim 2, wherein the function applied to the interpolated pixel-adjustment value comprises one or more of:

addition;

subtraction;

multiplication;

division;

averaging; and

other mathematical functions.

5. The method of claim 1, wherein applying the pixel-adjustment values to the pixels within the frame involves applying the pixel-adjustment values as a mask to the frame.

6. The method of claim 5, wherein if the mask is removed, the original pixel values for the frame are restored.

7. The method of claim 1, wherein a control point comprises:

a location of the control point within the frame; and

magnitudes of one or more pixel-adjustment values for the control point.

8. The method of claim 1, wherein a pixel value comprises one or more of:

an alpha value for an associated pixel;

a luminance value for an associated pixel;

chrominance values for an associated pixel; and

gamma-correction values for an associated pixel.

9. The method of claim 1, wherein the control points are associated with one or more window objects.

10. The method of claim 1, wherein prior to receiving one or more control points, the method further comprises defining control points within the frame.

11. A display unit, comprising:

a receiver circuit configured to;

receive a frame to be displayed from a memory; and

receive coordinates and pixel-adjustment values for one or more control points within the frame;

a pixel-adjustment-calculation circuit configured to calculate pixel-adjustment values for pixels in the frame based on the coordinates and the pixel-adjustment values for the one or more control points; and

a pixel-adjustment circuit configured to apply the pixel-adjustment values to the pixels within the frame.

12. The display unit of claim 11, further comprising an output driver circuit configured to drive a display with the pixel values for the frame.

13. The display unit of claim 11, further comprising a register set, wherein the register set is configured to store one or more of:

locations of control points within the frame;

magnitudes of one or more pixel-adjustment values;

pointers to the frame in the memory;

the dimensions of the frame;

the dimensions for a subset of the frame;

a color format for the frame; and

a color format for a subset of the frame.

14. A system, comprising:

a memory; and

a display unit, comprising;

a receiver circuit configured to;

receive a frame to be displayed from a memory; and

receive coordinates and pixel-adjustment values for one or more control points within the frame;

a pixel-adjustment-calculation circuit configured to calculate pixel-adjustment values for pixels in the frame based on the coordinates and the pixel-adjustment values for the one or more control points; and

a pixel-adjustment circuit configured to apply the pixel-adjustment values to the pixels within the frame.

15. The system of claim 14, wherein the system is a portable device.

16. The system of claim 14, further comprising one or more of:

a central-processing unit coupled to the bus;

a graphics-processing unit coupled to the bus;

a video decoder coupled to the bus; and

an image decoder coupled to the bus.

17. The system of claim 14, further comprising a display coupled to the display unit, wherein the display is configured to display the frame.

18. A computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for adjusting pixel values within a frame to be displayed, wherein the method comprises:

receiving coordinates and pixel-adjustment values for one or more control points within the frame;

calculating pixel-adjustment values for pixels in the frame based on the coordinates and the pixel-adjustment values for the one or more control points;

applying the pixel-adjustment values to the pixels within the frame; and

displaying the frame.

19. The computer-readable storage medium of claim 18, wherein calculating pixel-adjustment values for the frame involves:

for each degree-of-freedom within the frame, interpolating pixel-adjustment values for the pixels between the one or more control points; and

for each pixel, applying a function to the interpolated pixel-adjustment values for each degree-of-freedom to generate a pixel-adjustment value for the pixel.

20. The computer-readable storage medium of claim 19, wherein interpolating the pixel-adjustment values involves using one or more of:

a linear interpolation technique;

a polynomial interpolation technique; and

a spline interpolation technique.