Graphics resampling system and method for use thereof

• US 6,765,578 B2
• Filed: 08/30/2001
• Issued: 07/20/2004
• Est. Priority Date: 08/30/2001
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Slavin, Keith R.
• Primary Examiner(s): Bella, Matthew C.
• Assistant Examiner(s): Monestime, Mackly
• Application Number:
  US09/944,937
• Publication Number:
  US 20030043159A1
• Time in Patent Office: 1,055 Days
• Field of Search: 345/559, 345/603, 345/604, 345/606, 345/472, 345/649, 382/295, 382/296, 382/297, 382/298, 382/300
• US Class Current: 345/472
• CPC Class Codes: G06T 1/60 Memory management
• 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
• CPC Class Codes: G06T 3/4023 based on decimating pixels or lines of pixels; based on inserting pixels or lines of pixels
• CPC Class Codes: G09G 2340/0414 Vertical resolution change
• CPC Class Codes: G09G 2340/0421 Horizontal resolution change
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/363 Graphics controllers

Abstract

A resampling circuit and method where input sample values for samples arranged along a row of a source image are received by a row resampling circuit. The row resampling circuit calculates row output values which are provided to a column resampling circuit that calculates output sample values therefrom. The column resampling circuit includes a shift register that receives the row output values and shifts the row output values through the shift register as the row output samples are calculated. The shift register has a plurality of evenly spaced sample output terminals from which the row output values are sampled by an interpolation circuit for calculation of the output sample values.

Claims

1. A resampling circuit, comprising:

first resampling circuitry for calculating row output sample values from input sample values of samples along rows of a source image;

a shift register having an input terminal coupled to the resampling circuit to receive the row output sample values and further having a plurality of evenly spaced sample output terminals, the shift register shifting the row output sample values through the shift register as the row output sample values are calculated; and

second resampling circuitry coupled to the input terminal and the output terminals of the shift register to sample the row output sample values shifting therethrough, the second resampling circuit calculating output sample values from the row output sample values sampled from the sample output terminals.

2. The resampling circuit of claim 1 wherein the second resampling circuitry calculates the output sample values by interpolating from a cubic model.

3. The resampling circuit of claim 2 wherein the cubic model is calculated from five row output sample values.

4. The resampling circuit of claim 1 wherein the second resampling circuitry calculates the output samples from a first interpolation model for row output samples representing text images and from a second interpolation model for row output samples representing video images.

5. The resampling circuit of claim 1, further comprising a output buffer coupled to the second resampling circuitry into which column output sample values are stored.

6. A resampling circuit, comprising:

a row resampling circuit for receiving input sample values of samples along a row of a source image and providing row output values at an output terminal; and

a column resampling circuit coupled to the output terminal of the row resampling circuit, the column resampling circuit calculating output sample values from the row output values provided by the row resampling circuit, the column resampling circuit having a shift register receiving the row output values from the row resampling circuit and shifting the row output values through the shift register as the row output values are calculated, the shift register further having a plurality of evenly spaced sample output terminals at which the row output values are sampled for the output sample value calculation.

7. The resampling circuit of claim 6 wherein the row resampling circuit comprises:

a plurality of series coupled registers through which the input sample values are shifted from a first register to a last register, each of the registers having input and output terminals and having a same data capacity; and

an interpolation circuit coupled to the input terminal of the first register and further coupled to the output terminals of each register, the interpolation circuit calculating row output values from the input sample values sampled from the input terminal of the first register and the output terminals of each register.

8. The resampling circuit of claim 7 wherein each of the data capacity of each register is sufficient to store the graphics data for one sample of the source image.

9. The resampling circuit of claim 7 wherein the plurality of series coupled registers comprises four series coupled registers.

10. A graphics processing system, comprising:

a bus interface for coupling to a system bus;

a graphics processor coupled to the bus interface to process graphics data;

address and data busses coupled to the graphics processor to transfer address and graphics data to and from the graphics processor;

display logic coupled to the data bus to drive a display; and

a resampling circuit coupled to the graphics processor and adapted to calculate output sample values from input sample values corresponding to input samples of a source image that are arranged in rows and columns, the resampling circuit comprising;

first resampling circuitry for calculating row output sample values from input sample values of samples along rows of a source image;

a shift register having an input terminal coupled to the resampling circuit to receive the row output sample values and further having a plurality of evenly spaced sample output terminals, the shift register shifting the row output sample values through the shift register as the row output samples are calculated; and

second resampling circuitry coupled to the input terminal and the output terminals of the shift register to sample the row output sample values shifting therethrough, the second resampling circuit calculating output sample values from the row output sample values sampled from the sample output terminals.

11. The graphics processing system of claim 10 wherein the resampling circuit further comprises an output buffer coupled to the second resampling circuitry to store the output sample values calculated therefrom.

12. The graphics processing system of claim 10 wherein the plurality of sample output terminals of the resampling circuit comprises four output terminals.

13. The graphics processing system of claim 10 wherein the first resampling circuitry comprises:

a plurality of series coupled registers through which the input sample values are shifted from a first register to a last register, each of the registers having input and output terminals and having a same data capacity; and

an interpolation circuit coupled to the input terminal of the first register and further coupled to the output terminals of each register, the interpolation circuit calculating row output sample values from the input sample values sampled from the input terminal of the first register and the output terminals of each register.

14. The graphics processing system of claim 10 wherein the second resampling circuitry of the resampling circuit calculates the output sample values by interpolating from a cubic model.

15. The graphics processing system of claim 10 wherein the second resampling circuitry of the resampling circuit calculates the output samples from a first interpolation model for row output samples representing text images and from a second interpolation model for row output samples representing video images.

16. A computer system, comprising:

a system processor;

a system bus coupled to the system processor;

a system memory coupled to the system bus; and

a graphics processing system coupled to the system bus, the graphics processing system, comprising;

a bus interface for coupling to a system bus;

a graphics processor coupled to the bus interface to process graphics data;

address and data busses coupled to the graphics processor to transfer address and graphics data to and from the graphics processor;

display logic coupled to the data bus to drive a display; and

a resampling circuit coupled to the graphics processor and adapted to calculate output sample values from input sample values corresponding to input samples of a source image that are arranged in rows and columns, the resampling circuit comprising;

first resampling circuitry for calculating row output sample values from input sample values of samples along rows of a source image;

a shift register having an input terminal coupled to the resampling circuit to receive the row output sample values and further having a plurality of evenly spaced sample output terminals, the shift register shifting the row output sample values through the shift register as the row output samples are calculated; and

second resampling circuitry coupled to the input terminal and the output terminals of the shift register to sample the row output sample values shifting therethrough, the second resampling circuit calculating output sample values from the row output sample values sampled from the sample output terminals.

17. The computer system of claim 16 wherein the resampling circuit of the graphics processing system further comprises an output buffer coupled to the second resampling circuitry to store the output sample values calculated therefrom.

18. The computer system of claim 16 wherein the first resampling circuitry of the graphics processing system comprises:

a plurality of series coupled registers through which the input sample values are shifted from a first register to a last register, each of the registers having input and output terminals and having a same data capacity; and

an interpolation circuit coupled to the input terminal of the first register and further coupled to the output terminals of each register, the interpolation circuit calculating row output sample values from the input sample values sampled from the input terminal of the first register and the output terminals of each register.

19. The computer system of claim 16 wherein the second resampling circuitry of the resampling circuit calculates the output sample values by interpolating from a cubic model.

20. The computer system of claim 16 wherein the second resampling circuitry of the resampling circuit calculates the output samples from a first interpolation model for row output samples representing text images and from a second interpolation model for row output samples representing video images.

21. A method for calculating output sample values from input sample values corresponding to input samples of a source image that are arranged in rows and columns, respectively, the method comprising:

calculating row output values from a span of input samples for a plurality of adjacent rows;

providing the calculated row output values for the span of input samples for the plurality of adjacent rows to a first register of a plurality of series coupled registers;

sampling a plurality of row output values spaced at equal intervals in response to the calculation of a row output value; and

calculating output values from the sampled row output values.

22. The method of claim 21, further comprising temporarily storing the output values.

23. The method of claim 21 wherein sampling a plurality of row output values comprises shifting the row output values through a plurality of series coupled registers in response to the calculation of a row output value, each register having the same data length.

24. The method of claim 21 wherein calculating row output values, providing the row output values, sampling a plurality of row output values, and calculating output values is repeated at least once.

25. A method for calculating output sample values from input sample values of corresponding samples that arranged in rows and columns, the method comprising:

calculating row sample values from the input sample values of a portion of samples from a plurality of adjacent rows;

selecting a portion of row samples from a plurality of adjacent rows;

sampling a row sample value from each of the portions of row samples of adjacent rows, the sampled row sample value of each portion located in the same relative position within the respective portion of row samples; and

calculating output values from the sampled row sample values.

26. The method of claim 25 wherein the calculating output values comprises interpolating output values from a cubic model.

27. The method of claim 25 wherein the cubic model is calculated from five first axis output values.

28. The method of claim 25 wherein calculating output values comprises calculating the output samples from a first interpolation model for first axis output samples representing text images and from a second interpolation model for first axis output samples representing video images.