CN100437743C - Display color adjust - Google Patents

Abstract

Systems and methods to linearly scale the colors of display data in a display driver circuit before it is written in a display RAM have been achieved. Said systems and methods invented are applicable to any display type such as e.g. CSTN, DSTN, TFT, OLED, etc. Each primary color value, e.g. red, green and blue is individually adjusted with its own setting, which allows maximum flexibility in display adjustment. Set adjustment is performed to adjust the colors displayed to the specific color characteristics of any display screen type. A system processor sets the red, green and blue color adjust register settings for a particular display type. The display data is downloaded from a system processor into a display RAM via a display adjust circuit, Said display adjust circuit modifies the display data according to the color adjust register setting settings before it is written into the RAM.

Description

Display Color Adjustment

technical field

This invention relates generally to display systems, and more particularly to a system and method for adjusting the color to be displayed prior to writing the color to be displayed in display RAM.

Background technique

It is often necessary to adjust the color of a digital image to suit the display system used to display the digital image. Without any adjustments, viewers of digital images will be dissatisfied with the displayed colors. All display systems such as Color Super Twisted Nematic (CSTN), Thin Film Transistor (TFT), Organic Light Emitting Diode (OLED), or Double Layer Super Twisted Nematic (DSTN) displays have their own unique drawbacks in displaying color. Therefore, the color of a digital image must be adjusted to meet the expectations of the viewer of the image.

There are various known methods to perform the color adjustment.

US Patent No. 6,262,817 (by Sato et al.) describes a color image system for adjusting the color of an input image, which includes a color adjustment unit and a color display unit. The color display unit simultaneously displays the original image, the adjusted image, and color information of the original image and the adjusted image. The color adjustment unit creates a color adjustment matrix based on color directions input to the color display unit, color information on the original color image. A color adjustment matrix is used to directly adjust the original image without converting the image to a second color space. The color adjustment unit generates a color adjustment matrix by adding color adjustment directions of brightness, chroma, and hue directed by the image display unit used to the original matrix. After the color adjustment matrix is generated, the adjusted pixels can be generated by calculating the original pixels and the color adjustment matrix.

U.S. Patent No. 6,388,648 (to Clifton et al.) discloses an LCD projection unit using a brightness and color balancing system that uses an LCD array characteristic look-up table that stores multiple sets of Choose the brightness and gamma correction values to control brightness and color balance. The lookup table values are determined by measuring the transfer of the LCD array in the projection unit for each of a set of red ("R"), green ("G"), and blue ("B") input data values function that converts the resulting S-response curve into a corresponding set of gamma responses, and scales the gamma responses to generate multiple R, G, and B families of luminance and gamma-corrected values. Color balance is adjusted by selecting a specific R, G, B family of luminance and gamma corrected values that matches the LCD projection unit to a predetermined ratio of R, G, B luminance values. Brightness is adjusted by selecting a set of R, G, B families and brightness values that maintains the color balance ratio while allowing the LCD to deliver the desired full brightness. The primary colors are adjusted by a color mixing method implemented by a mathematical matrix algorithm that generates color modification coefficients for a color space conversion circuit. The primary color matching algorithm involves: determining the intrinsic color coordinates of the primary colors, determining a predetermined set of target coordinates, and performing matrix operations to calculate the coefficients used in the color space conversion circuit to convert the measured coordinates to target coordinates so as to match the primary colors. match. When the primary colors are matched, the color balance and brightness matching system described above adjusts the white and gray balance to form a better matched multi-screen display system.

U.S. Patent No. 4,409,614 (by Eichler et al.) discloses a method in which a color scan signal generated by scanning an original image is first converted into a three-primary color signal having a theoretical relationship with the primary colors in a predetermined color coordinate system The color values are substantially the same as the actual color values. Only after this conversion is the primary color signals or signals derived from these signals converted to another color reproduction system, or to change the gradation, or to change the color reproduction of individual colors in all images or discrete areas, Or any other non-linear processing takes place.

Contents of the invention

The main purpose of the present invention is to linearly scale the color of display data.

Another object of the invention is to achieve a low-cost solution for scaling the colors of display data.

Yet another object of the present invention is to achieve very fast color adjustment processing of display data.

According to the object of the present invention, a system for adjusting the colors in any kind of electronic display is realized. The system includes: a color screen serving as a display using primary colors of a color space; a system processor for sending downloaded display data to a display driver circuit; and a display driver circuit. The display driver circuitry includes: processor interface logic for providing an interface between the system processor and the display driver circuitry; display conditioning circuitry for conditioning processing from the system via the processor interface logic display data received by the monitor, and writes the modified display data to the display RAM, wherein the adjustment is performed for each color by linear scaling by a programmable amount according to the equation, and the corresponding multiplier factor is selected to give one or more color adjustment registers; a display RAM for storing adjusted display data; and a screen driver for controlling the screen and sending the adjusted display data to the screen.

According to the object of the present invention, a method of adjusting the colors in any kind of electronic display is invented. The method includes first providing a color screen, a system processor, and display driver circuitry including processor interface logic, display adjustment circuitry, one or more color adjustment registers, display RAM, and screen driver circuitry. The steps of the method are: defining adjustment data for each primary color used by the display screen for adjusting the color according to the properties of the screen; providing one or more bits for each primary color Store said adjustment data for each primary color in one or more registers; define a word structure for manipulating unadjusted display data and for storing adjusted display data in display RAM, where for each primary color the the prescribed number of bits; and an algorithm for adjusting each primary color used by the screen is implemented in the display adjustment circuit using a hardware description language. These steps are followed by: downloading the display data from the system processor to the display conditioning circuit; conditioning the display data in the display conditioning circuit according to an algorithm implemented earlier, wherein the algorithm includes a factor of 2 ⁿ , where n is according to the earlier definition and storing the adjustment data corresponding to the desired adjustment parameters set for each primary color, and writing the adjusted display data to the display RAM; and transferring the adjusted display data from the display RAM to the display screen through the screen driver circuit .

Description of drawings

In the accompanying drawings forming an integral part of this specification, it is shown:

Figure 1 illustrates the basic components of the invented system in a block diagram;

Figure 2 shows a flowchart of the invented method.

Detailed ways

The preferred embodiment discloses a system and method for linearly scaling display data prior to writing the display data to display RAM. Embodiments of the present invention are applicable to any electronic display type such as color super twisted nematic (CSTN), thin film transistor (TFT), organic light emitting display (OLED), or double layer super twisted nematic (DSTN) displays. Compared to prior art solutions, the invented system and method provide a fast and very cost-effective way of adjusting the color of a digital image according to the color characteristics of the type of display used.

Figure 1 shows a block diagram of a preferred embodiment of the present invention. The display system shows the display driver IC 1, which is the key to the invention. In addition, the system also includes a display 2 and a system processor 3 . As mentioned above, the display 2 may be any type of display. Compared with the prior art, the display driver IC 1 is characterized by: having a display adjustment circuit 6 which receives unadjusted display data from the processor interface logic 7; adjustment using color adjustment registers 8 for red, green and blue The unadjusted display data; and writing the adjusted display data to the display RAM 5, which contains the display data to be displayed on the screen display 2. In addition, the system includes a screen driver circuit 4 for driving the screen display.

For those skilled in the art, it is obvious that the above-mentioned display driver circuit is suitable to be realized by an ASIC circuit.

The displayed color can be adjusted by simple integer multiplication of the color data values before writing to the display RAM 5. In a preferred embodiment, a 65K color display separates 16-bit words into red, green and blue components. In other embodiments, color displays using other color spaces than RGB, such as CMY, may also be used.

The following table shows the word structure used in one embodiment of the present invention. In the 16-bit structure chosen in the preferred embodiment, 5 bits are provided for red, 6 bits for green and 5 bits for blue. Using the word structure shown in the table below, in the case of unadjusted display data, 32 different values for red, 64 different values for green, and 32 different values for blue can be displayed. This will result in a palette with 32x64x32, which means 65536 different colors.

Each color value is individually adjusted with its own setting, which allows maximum flexibility in display adjustment. The system processor 3 sets the red, green and blue tuning register settings for a particular display (eg LCD, TFT, OLED). The display data is downloaded from the system processor 3, and the display color adjustment circuit 6 adjusts it before writing the display data into the display RAM 5.

Display data in the preferred embodiment is linearly scaled by programmable quantities. The multiplier factor is chosen to give a simple logical implementation.

The table below shows red in 5 bits according to the multiplier factor n, the associated scaling factor, the mathematical equation used, the associated percent change in red color, and the associated number of colors that can be displayed. Obviously, the color blue, also expressed in 5 bits, has exactly the same properties as the modulation of red as shown in the table below. Therefore, there is no separate table for blue.

The table below shows how to decrease or increase the color red depending on the multiplier factor n and the positive or negative algebraic sign of the mathematical equation used. It should be understood that the mathematical operations used can be performed very quickly by simple manipulation of internal registers. The right column shows how the number of different colors that can be fully displayed decreases according to how much red is increased or decreased. This reduction in color number is due to mathematical operations (shifting of registers) during adjustment. Likewise, the color blue has the same value as red shown in the table below.

conversion factor math equation Where n = %Variety Color number Red × 3/4 red-red/2ⁿ 2 -25% 25 Red × 7/8 red-red/2ⁿ 3 -12.5% 29 Red×15/16 red-red/2ⁿ 4 -6.3% 31 Red × 1 no change 0 32 Red×17/16 Red+red/2ⁿ 4 +6.3% 31 Red×9/8 Red+red/2ⁿ 3 +12.5% 29 Red × 5/4 Red+red/2ⁿ 2 +25% 26

If the math equation red+red/2 ⁿ is greater than 31, the result is limited to 31 due to the 5-bit limit.

The following table shows the value of color represented by 6 bits. As explained above, green is represented by 6 bits in one embodiment of the present invention. The table below shows the same columns as the table above. Compared with the 5 bits in the previous table, it is obvious that by using 6 bits, the adjustment can be made in an additional two steps (one step for each increase or decrease in the color value), and the number of different colors can be displayed Significantly higher.

conversion factor math equation Where n = %Variety Color number Green × 3/4 green-green/2ⁿ 2 -25% 49 Green×7/8 green-green/2ⁿ 3 -12.5% 57 Green×15/16 green-green/2ⁿ 4 -6.3% 61 Green×31/32 green-green/2ⁿ 5 -3.1% 63 Green × 1 no change 0 64 Green×33/32 green+green/2ⁿ 5 +3.1% 63 Green×17/16 green+green/2ⁿ 4 +6.3% 61 Green×9/8 green+green/2ⁿ 3 +12.5% 57 Green × 5/4 green+green/2ⁿ 2 +25% 52

If the math equation green+green/ ²ⁿ is greater than 63, the result is limited to 63 due to the 6-bit limit.

As previously mentioned, in the preferred embodiment of the present invention, with 5 bits for each of red and blue and 6 bits for green, 65536 different colors can be displayed using unadjusted color values palette. Typical adjustments include a 0% change in red, a +6% change in green, and a 0% change in blue. Using the typical adjustments, 32 different values of red, 61 different values of green and 32 different values of blue can be displayed. This will result in a palette with 32x61x32, which means 62464 different colors can be displayed. A tighter regulation would result in a -12% change in red and blue and a +6% change in green. This will result in a palette of 29x61x29, which means that 51301 different colors can still be displayed.

The following table shows how the color adjustment registers are used to store color adjustment information in a preferred embodiment of the present invention. In the preferred embodiment, two registers each having 8 bits (B0 to B7) are used. In Register 1, three bits B0 to B2 are used to store red color adjustment data (RCA2:0). Store the blue color adjustment data (BCA 2:0) in the three bits B4 to B6 of register 1. Store the green color adjustment data (GCA 3:0) in four bits B0 to B3 of register 2.

The table below shows how the three bits for red adjustment (RCA 2:0) are used in the preferred embodiment. The percentage values in the table below show the increase/decrease of the red color value.

011＝+25% (2 bits shifted and added)

010＝+12.5% (3 bits shifted and added)

001＝+6.3% (4 bits shifted and added)

000 = no change (default)

101=-6.3% (4 bits shifted and subtracted)

110=-12.5% (3 bit shift and subtraction)

111=-25% (2 bits shifted and subtracted)

The same bit arrangement is also used for the blue color adjustment BCA(2:0) with three bits of adjustment data. As shown in the register table above, the green adjustment GCA(3:0) is performed using four bits of adjustment data. For example, in the preferred embodiment of the present invention, the bit arrangement for green adjustment is as follows:

0100＝+25% (2 bits shifted and added)

0011＝+12.5% (3 bits shifted and added)

0010＝+6.3% (4 bits shifted and added)

0001＝+3.1% (5 bits shifted and added)

0000 = no change (default)

1001=-3.1% (5 bits shifted and subtracted)

1010=-6.3% (4 bits shifted and subtracted)

1011=-12.5% (3 bits shifted and subtracted)

1100=-25% (2 bits shifted and subtracted)

For the realization of the above algorithm in the display adjustment circuit 6, a register transfer level code (register transfer level code, RTL) language has been used in a preferred embodiment. Although RTL is very efficient, other hardware description languages (HDLs) can also be used. An example of the RTL code for red tuning is shown here:

module(code, rca, res)

input code[5], rca[3];

output res[5];

reg a[5], b[5], c[6], ci;

//reset register b

b=5'b00000;

if(rca[1:0]==2'b01)//4 bit shift

begin

  b[0]=code[5];

end

if(rca[1:0]==2'b10)//3 bit shift

begin

` b[1]=code[5];

  b[0]=code[4];

end

if(rca[1:0]==2'b11)//2 bit shift

begin

` b[2]=code[5];

` b[1]=code[4];

  b[0]=code[3];

end

if(rca[2]==1'b0)//addition

begin

ci=1'b0;

a=b;

end

else

begin//Using the subtraction of the two's complement mathematics

ci=1'b1;

A = ~ b;

end

//Code addition

assign c=code+a+ci;

// check execution and addition

if((c[5]==I'b1)&&(rca[2]==1'b0))

res=5'b11111;

else

res = c;

endmodule;

For those skilled in the art, the above example demonstrates how simple and fast color adjustments can be made in the preferred embodiment.

Figure 2 shows a related method of scaling display data in a display driver circuit before writing the display data into display RAM. The first step 21 of the method defines adjustment data for each primary color used by the display screen in order to adjust the colors according to the properties of the screen. A subsequent step 22 stores said adjustment data for each primary color in one or more registers providing one or more bits for each primary color. Step 23 describes the definition of the word structure to manipulate the unscaled display data and store the scaled data in the display RAM with the specified number of bits assigned to each primary color. The next step 24 shows the algorithm implemented in the display adjustment circuit using hardware description language to adjust each primary color used by the screen. Now in step 25 the display data is downloaded from the system processor to the display conditioning circuit and subsequently in step 26 the display data adjusted in the display conditioning circuit according to the previously implemented algorithm and according to the previously defined and stored conditioning data written to display RAM. In a final step 27, the conditioned display data is passed from the display RAM to the display screen via the screen driver circuit.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.

Claims (35)

1. the system of the colour in the electronic console of regulating any kind of comprises:

Color/graphics, it is as the display of the primary colors that uses the color space;

System processor, the video data that is used for downloading is sent to display driving circuit; And display driving circuit, comprising:

The processor interface logic is used to provide the interface between described system processor and the described display driving circuit;

Show regulating circuit, be used to regulate the video data that receives from described system processor via described processor interface logic, and the video data of described modification is written to display random access memory, wherein pass through linear the conversion by programmable amount, and corresponding multiplier factor is selected to provide the simple logic realization for the described adjusting of each colored execution according to equation;

One or more adjustment of color registers;

Display random access memory is used for the video data after the stored adjustment; With

Screen drive is used to control described screen and the video data after the described adjusting is sent to described screen.

2. the system as claimed in claim 1, wherein said color space is RGB.

3. the system as claimed in claim 1, wherein said color space is CMY.

4. the system as claimed in claim 1, wherein said screen is a LCD display.

5. system as claimed in claim 4, wherein said LCD display are the CSTN displays.

6. system as claimed in claim 4, wherein said LCD display are the DSTN displays.

7. the system as claimed in claim 1, wherein said screen is the TFT display.

8. the system as claimed in claim 1, wherein said screen is the OLED display.

9. the system as claimed in claim 1, wherein said demonstration regulating circuit use two adjustment of color registers to come the adjusting data of area definition regulated quantity.

10. system as claimed in claim 9, wherein said adjustment of color register-stored are used for each adjusting data of all primary colors of selected color space.

11. system as claimed in claim 10, wherein said adjustment of color register comprises each three of adjusting information that are respectively applied in two primary colors of storage, and is used for four of the third primary colors.

12. system as claimed in claim 11, wherein said adjustment of color register comprises each three of adjusting information that are respectively applied in the red and blueness of storage, and is used for four of green.

13. the system as claimed in claim 1 wherein uses 16 words that described video data is stored in the described display random access memory.

14. system as claimed in claim 13, wherein said 16 words comprise each five that are respectively applied in two primary colors, and are used for six of the third primary colors.

15. system as claimed in claim 14, wherein said 16 words comprise each five that are respectively applied in red and the blueness, and are used for six of green.

16. the system as claimed in claim 1 is every kind of adjustment of color video data according to the equation that uses hardware description language to realize in described demonstration regulating circuit wherein.

17. system as claimed in claim 16 is every kind of adjustment of color video data according to the equation that uses register transfer level (RTL) language to realize in described demonstration regulating circuit wherein.

18. the system as claimed in claim 1 is wherein passed through equation color in the situation that needs primary colors to reduce _Adjust=color _Unadjust-color _Unadjust/ 2 ⁿDefine described programmable amount,

Color wherein _AdjustBe the value of color after regulating, color _UnadjustBe unadjusted value of color, n is the parameter that is adjusted to every kind of primary colors setting according to desirable.

19. the system as claimed in claim 1 is wherein passed through equation color in the situation that needs primary colors to increase _Adjust=color _Unadjust+ color _Unadjust/ 2 ⁿDefine described programmable amount,

Color wherein _AdjustBe the value of color after regulating, color _UnadjustBe unadjusted value of color, n is the parameter that is adjusted to every kind of primary colors setting according to desirable.

20. the system as claimed in claim 1, wherein said display driving circuit is implemented as IC.

21. the system as claimed in claim 1, wherein said display driving circuit is implemented as ASIC.

22. the method for the colour in the electronic console of regulating any kind of comprises:

Color/graphics, system processor and display driving circuit are provided, and this display driving circuit comprises the processor interface logic, shows regulating circuit, one or more adjustment of color registers, display random access memory and screen drive circuit;

Definition is used for regulating described colour according to the attribute of described screen by the adjusting data of each primary colors of described display screen use;

Storage is used for the described adjusting data of every kind of primary colors in one or more one or more registers are provided for every kind of primary colors;

The defined word structure is used to operate unadjusted video data, and is used for the video data after regulating is stored in display random access memory, has wherein distributed the figure place of defined for every kind of primary colors;

Use hardware description language in described demonstration regulating circuit, to realize by described screen algorithm that use, that be used to regulate every kind of primary colors;

Video data is downloaded to the demonstration regulating circuit from system processor;

Regulate the video data that shows in the regulating circuit according to the algorithm of previous realization, wherein said algorithm comprises the factor 2 ⁿ, wherein n is adjusted to the parameter that every kind of primary colors is set according to the previous adjusting data that define and store corresponding to desirable, and the video data after will regulating is written to display random access memory; With

Video data after will regulating by the screen drive circuit is sent to screen from display random access memory.

23. method as claimed in claim 22, wherein said primary colors belongs to the RGB color space.

24. method as claimed in claim 22, wherein said primary colors belongs to the CMY color space.

25. method as claimed in claim 22, wherein said word structure comprises 16 word.

26. method as claimed in claim 25, wherein said 16 words comprise each five that are respectively applied in two primary colors, and are used for six of the third primary colors.

27. method as claimed in claim 26, wherein said 16 words comprise each five that are respectively applied in red and the blueness, and are used for six of green.

28. method as claimed in claim 22, wherein said hardware description language are register transfer level (RTL) language.

29. method as claimed in claim 22, the wherein said algorithm that reduces primary color value is

color _adjust＝color _unadjust-color _unadjust/2 ⁿ，

Color wherein _AdjustBe the value of color after regulating, color _UnadjustBe unadjusted value of color, n is the parameter that is adjusted to every kind of primary colors setting according to desirable.

30. the system as claimed in claim 22, the algorithm of wherein said increase primary color value is

color _adjust＝color _unadjust+color _unadjust/2 ⁿ，

Color wherein _AdjustBe the value of color after regulating, color _UnadjustBe unadjusted value of color, n is the parameter that is adjusted to every kind of primary colors setting according to desirable.

31. method as claimed in claim 22, wherein said adjustment of color register comprise each three of adjusting data that are respectively applied in two primary colors of storage, and are used for four of the third primary colors.

32. method as claimed in claim 31, wherein said adjustment of color register comprise each three of adjusting data that are respectively applied in the red and blueness of storage, and are used for four of green.

33. method as claimed in claim 32, the wherein said adjusting data that are used for redness are following bit patterns:

011=+25%, it indicates 2 bit shifts and addition,

010=+12.5%, it indicates 3 bit shifts and addition,

001=+6.3%, it indicates 4 bit shifts and addition,

The 000=no change, it indicates default value,

101=-6.3%, it is indicated 4 bit shifts and subtracts each other,

110=-12.5%, it is indicated 3 bit shifts and subtracts each other,

111=-25%, it is indicated 2 bit shifts and subtracts each other.

34. method as claimed in claim 32, the wherein said adjusting parameter that is used for blueness is following bit pattern:

011=+25%, it indicates 2 bit shifts and addition,

010=+12.5%, it indicates 3 bit shifts and addition,

001=+6.3%, it indicates 4 bit shifts and addition,

The 000=no change, it indicates default value,

101=-6.3%, it is indicated 4 bit shifts and subtracts each other,

110=-12.5%, it is indicated 3 bit shifts and subtracts each other,

111=-25%, it is indicated 2 bit shifts and subtracts each other.

35. method as claimed in claim 31, the wherein said adjusting parameter that is used for green is following bit pattern:

0100=+25%, it indicates 2 bit shifts and addition

0011=+12.5%, it indicates 3 bit shifts and addition

0010=+6.3%, it indicates 4 bit shifts and addition

0001=+3.1%, it indicates 5 bit shifts and addition

The 0000=no change, it indicates default value

1001=-3.1%, it is indicated 5 bit shifts and subtracts each other

1010=-6.3%, it is indicated 4 bit shifts and subtracts each other

1011=-12.5%, it is indicated 3 bit shifts and subtracts each other

1100=-25%, it is indicated 2 bit shifts and subtracts each other.

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