Method and apparatus for scaling and blending an image to be displayed

• US 5,764,238 A
• Filed: 09/10/1993
• Issued: 06/09/1998
• Est. Priority Date: 09/10/1993
• Status: Expired due to Term

• Current Assignee: ATI Technologies Incorporated (Advanced Micro Devices, Inc.)
• Original Assignee: ATI Technologies Incorporated (Advanced Micro Devices, Inc.)
• Inventors: Lum, Sanford S., Bennett, Dwayne R.
• Primary Examiner(s): Jankus, Almis R.
• Application Number:
  US08/118,896
• Time in Patent Office: 1,733 Days
• Field of Search: 395/133, 395/139, 395/128, 395/129, 395/141, 395/142, 395/143, 382/41, 382/44-47, 382/52, 345/136-138
• US Class Current: 345/660
• CPC Class Codes: G06T 2200/28 involving image processing hardware
• CPC Class Codes: G06T 3/4007 based on interpolation, e.g. bilinear interpolation image demosaicing G06T3/4015; edge-driven or edge-based scaling G06T3/403

Abstract

The present invention relates to an image scaler comprised of apparatus for receiving coefficients a and b and image display values of adjacent pixels P and Q respective of an image, apparatus for repeatedly operating on the coefficients and values for successive pixels according to the transform ##EQU1## where SUM is the sum of the coefficients,

R is either zero or the accumulated SUM of an immediately preceding operation,

A_cc is an accumulated result signal, and apparatus for providing a first result signal as an output coefficient word for controlling the display of each of adjacent pixels.

Claims

1. An image scaler comprising:

(a) means for receiving a data signal representing scaling coefficients a and b and image display values of adjacent pixels P and Q respectively of an image,

(b) circuit means for repeatedly operating on said received coefficients and values for successive pixels according to the transform ##EQU17## where SUM is the sum of the values of the coefficients,

R is either zero or the accumulated result of an immediately preceding operation,

A_cc is an accumulated result signal, and

(c) means for providing a first result signal as an output coefficient word to apparatus for controlling the display of each of adjacent pixels.

2. An image scaler as defined in claim 1 in which the successive pixels are adjacent pixels of a horizontal line.

3. An image scaler as defined in claim 1 in which the successive pixels are adjacent pixels of adjacent lines.

4. An image scaler as defined in claim 1 in which the sum of said coefficients fixed.

5. An image scaler as defined in claim 4 in which the sum of said coefficients is 16.

6. An image scaler comprising:

(a) means for receiving a data signal representing scaling coefficients a and b and image display values or adjacent pixels P and O respectively of an image,

(b) circuit means for repeatedly operating on said received coefficients and values for successive pixels according to the transform ##EQU18## where SUM is the sum of the values of the coefficients.

R is either zero or the accumulated result of an immediately preceding operation,

A_cc is an accumulated result signal,

(c) means for providing a first result signal as an output coefficient word to apparatus for controlling the display of each of adjacent pixels

(d) the successive pixels being adjacent pixels of adjacent lines, and

(e) in which the coefficients a and b define adjacent vertical pixel coefficients a_v and b_v respectively, relating to vertically adjacent pixels values P_v and Q_v respectively, and further including means for receiving adjacent horizontal pixel coefficients a_H and b_H relating to the values of P_H and Q_H respectively of adjacent horizontal pixels respectively, means for receiving results of an operation on adjacent pixels of adjacent lines, and for performing operation on said coefficients a_H and b_H for the pixel values P_H and Q_H of successively adjacent pixels in horizontal lines resulting from a previous operation on said coefficients a_v and b_v for the pixel values P_v and Q_v respectively, and accumulating the result according to the transform ##EQU19## and providing a result as said first result signal for said controlling the display of adjacent pixels.

7. An image scaler comprising;

(a) means for receiving a data signal representing scaling coefficients a and b and image display values of adjacent pixels P and O respectively of an image,

(b) circuit means for repeatedly operating on said received coefficients and values for successive pixels according to the transform ##EQU20## where SUM is the sum of the values of the coefficients,

R is either zero or the accumulated result of an immediately preceding operation

A_cc is an accumulated result signal,

(c) means for providing a first result signal as an output coefficient word to apparatus for controlling the display of each of adjacent pixels,

(d) the successive pixels being adjacent pixels of a horizontal lines, and

(e) in which the coefficients a and b define adjacent vertical pixel coefficients a_H and b_H respectively, relating to vertically adjacent pixel values P_H and Q_H respectively, and further including means for receiving adjacent horizontal pixel coefficients a_v and b_v relating to the values of P_v and Q_v respectively of adjacent vertical pixels respectively, means for receiving results an operation on horizontally adjacent pixels, and for performing operations on said coefficients a_v and b_v for the pixel values P_v and Q_v of successively adjacent pixels lines resulting from a previous operation on said coefficients a_H and b_H for the pixel values P_H and Q_H, respectively, and accumulating the result, according to the transform ##EQU21## and providing a result as said first result signal for said controlling the display of adjacent pixels.

8. An image scaler comprising:

(a) a vertical blend ALU for performing the transform ##EQU22## (b) a horizontal blend ALU for performing the transform ##EQU23## where a_v, b_v, a_H and b_H are vertical and horizontal blending coefficients,

P and Q are respectively parameters relating to adjacent pixels,

SUM_v and SUM_H are respectively sums of the vertical and horizontal coefficients, and

R is either zero or the accumulated result of a previous operation,

(c) means for providing P and Q data of pairs of adjacent image lines to the vertical blend ALU,

(d) means for receiving and buffering the output of the vertical blend ALU for providing R data to the vertical blend ALU, and for providing P and Q data to the horizontal blend ALU,

(e) a pixel accumulator connected to the output of the horizontal blend ALU for providing R data to the horizontal blend ALU and for providing an output signal comprising pixel data resulting from expansion, contraction or unity transformation of the P and Q data.

9. An image scaler as defined in claim 8 in which the means for providing P and Q data related to pairs of adjacent lines is comprised of a first line buffer for receiving P and Q data from an input source and for outputting the Q data to a Q input of the vertical blend ALU, and a second line buffer for receiving the P and Q data and for outputting the P data to a P input of the vertical blend ALU, whereby the first and second line buffers provide later and earlier adjacent line pixel data respectively to the vertical blend ALU.

10. An image scaler as defined in claim 9 in which the means for receiving and buffering the output of the vertical blend ALU is comprised of a third line buffer.

11. An image scaler as defined in claim 9 in which the means for receiving and buffering the output of the vertical blend ALU is comprised of a pixel latch the output of which is applied to a P input of the horizontal blend ALU, the output of the vertical blend ALU being applied to a Q input of the horizontal blend ALU, and further comprising a multiplexer having a pair of inputs, one input being connected to receive the output of the first line buffer and another input being connected to receive the R data from the means for receiving and buffering the output of the vertical blend ALU, the multiplexer having an output connected to the input of the second line buffer.

12. An image scaler as defined in claim 8 in which both SUM_v and SUM_H are 16.

13. An image scaler comprising:

(a) a vertical blend ALU for performing the transform ##EQU24## (b) a horizontal blend ALU for performing the transform ##EQU25## where a_v, b_v, a_H and b_H are vertical and horizontal blending coefficients,

P and Q are respectively parameters relating to adjacent pixels,

SUM_v and SUM_H are respectively sums of the vertical and horizontal coefficients, and

R is either zero or the accumulated result of a previous operation,

(c) means for providing P and Q data of pairs of adjacent pixels of a line to the horizontal blend ALU,

(d) a pixel accumulator connected to the output of the horizontal blend ALU, for providing R data to the horizontal blend ALU,

(e) a multiplexer for receiving an output of signal of the pixel accumulator, having a pair of outputs, and having a control input for controlling on which of said outputs data is applied,

(f) a pair of line buffers, each having an input connected to an output of the multiplexer, the output of each of the line buffers respectively connected to corresponding Q and P inputs of the vertical blend ALU, and

(g) means for receiving and buffering the output of the vertical blend ALU, for providing R data to the vertical blend ALU, and for providing an output signal comprising pixel data resulting from expansion, contraction or unity transformation of P and Q.

14. An image scaler as defined in claim 13 in which the means for providing P and Q data of pairs of adjacent pixels is comprised of an input source connected to a P input of the horizontal blend ALU and through a pixel delay buffer to a Q input of the horizontal blend ALU.

15. A method of scaling images comprising:

(a) receiving data representing scaling coefficients a and b and image display values of adjacent pixels P and Q respectively of an image,

(b) repeatedly operating on said coefficients and values for successive pixels according to the transform ##EQU26## where SUM is the sum of the values of the coefficients,

R is either zero or the accumulated SUM of an immediately preceding operation,

A_cc is an accumulated result signal,

(c) providing a first result signal as an output coefficient word to apparatus for controlling the display of each of adjacent pixels.

16. A method of scaling images as defined in claim 15 in which the successive pixels are adjacent pixels of a horizontal line.

17. A method of scaling images comprising:

(a) receiving data representing scaling coefficients a and b and image display values of adjacent pixels P and 0 respectively of an image,

(b) repeatedly operating on said coefficients and values for successive pixels according to the transform ##EQU27## where SUM is the sum of the values of the coefficients,

R is either zero or the accumulated result of an immediately preceding operation,

A_cc is an accumulated result signal,

(c) providing a first result signal as an output coefficient word to apparatus for controlling the display of each of adjacent pixels,

(d) the successive pixels being adjacent pixels of a horizontal line, and

(e) in which the coefficients a and b define adjacent horizontal pixel coefficients a_H and b_H respectively relating to horizontally adjacent pixel values P_H and Q_H respectively, and further including receiving adjacent vertical pixel coefficients a_v and b_v relating to values P_v and Q_v respectively of adjacent vertical pixels respectively, receiving results of an operation on horizontally adjacent pixels, and performing operations on said coefficients a_v and b_v for the pixel values P_v and Q_v of adjacent pixels of successively adjacent lines resulting from a previous operation on said coefficients a_H and b_H for the pixel values P_H and Q_H, respectively, accumulating the result, according to the transform ##EQU28## and providing a result as said first result signal for said controlling the display of adjacent pixels.

18. A method of scaling images as defined in claim 17 in which the sum of said coefficients is fixed.

19. A method of scaling images comprising:

(a) performing in a vertical blend ALU the transform ##EQU29## (b) performing in a horizontal blend ALU the transform ##EQU30## where a_v, b_v, a_H and b_H are signals representing vertical and horizontal blending coefficients,

P and Q are signals respectively representing parameters relating to adjacent pixels in adjacent lines or in a single line,

SUM_v and SUM_H are signals respectively representing sums of the vertical and horizontal coefficients, and

R is a signal representing either zero or the accumulated result of a previous operation, and

(c) providing an output signal comprising pixel data resulting from expansion, contraction or unity transformation of P and Q in accordance with the aforenoted transforms, to apparatus for controlling the display of said resulting pixel data.