CN101465092A - Image display system and moire defect elimination method - Google Patents

Abstract

The invention provides an image display system and a moire defect elimination method. The memory stores a set of moire compensation parameters for pixels that require moire compensation. The parameter selector determines what a target pixel is being driven according to the driving signal of the pixel matrix, and determines whether the target pixel requires moire compensation. When the target pixel needs moire compensation, the parameter selector outputs a memory address of the memory at which the group of moire compensation parameters of the target pixel is located. According to the set of moire compensation parameters stored in the memory address, the compensation logic arithmetic unit generates a compensated gray value to drive the target pixel.

Description

Image display system and method for eliminating moiré defects

technical field

The invention relates to an image display system and a method for eliminating screen moiré defects.

Background technique

An image display system usually includes a pixel array (pixel array), which includes a plurality of pixels. There may be slight differences in the light emitting characteristics of each pixel, which will cause a mura defect when the pixel matrix displays an image; some pixels will be brighter and some pixels will be lower.

External compensation is a method to improve the above-mentioned moiré defect: generate a moiré compensation parameter set for each pixel according to the electronic characteristics or luminous characteristics of each pixel; store the above-mentioned moiré compensation parameter set in a memory; When a pixel is selected, the moiré compensation parameter set of the pixels is read from the memory; the original gray value of the pixel is compensated according to the read moiré compensation parameter set; and the pixel is driven with the compensated gray value.

The above-mentioned traditional external compensation technology performs gray value compensation for each pixel; the memory must store moiré compensation parameter sets for all pixels. As the screen resolution increases, the capacity of the memory must be increased, and the transmission bandwidth of the memory must be increased in order to cope with the high transmission volume required by the high-resolution screen.

Taking the QVGA (Quarter Video Graphics Array) image display system as an example, its screen resolution is 240 x 320, including R, G, B, W four sub-pixels, and the screen update speed is 60fps. If the moire corresponding to each sub-pixel If the compensation parameter set includes two moiré compensation parameters, the memory bandwidth must be at least:

240 x 320 x 4 x 60 x 2 = 36.9MHz.

If the above-mentioned traditional external compensation technology is applied to a VGA (Video Graphic Array) system with a higher resolution, the memory bandwidth will be greatly increased to at least 147MHz. In addition, high-speed access to memory also means high power consumption, which is very unfavorable for most handheld devices that are only powered by batteries.

Traditional methods to cope with large transfer volumes include: using memory with multiple output pins, reducing the screen update speed of the image display system, or adopting a multi-memory structure. A memory with multiple output pins (for example, a memory with 16-bit output instead of a memory with 8-bit output) can increase the bandwidth of the memory, but the cost of the memory with multiple pins is high and the yield rate is low. A low screen refresh rate can seriously affect the quality of moving images. The multi-memory structure not only increases the cost but also occupies a large area.

Therefore, there is a great need in the art for a novel moiré defect elimination technology to overcome the problems of insufficient memory bandwidth and excessive power consumption during memory access.

Contents of the invention

The invention provides an image display system, which includes a pixel matrix, a memory, a parameter selector, and a compensation logic operator. The memory is responsible for storing moiré compensation parameter sets of pixels in the pixel matrix that need moiré compensation. The parameter selector determines a target pixel to be driven according to the driving signal of the pixel matrix, and determines whether the target pixel needs moiré compensation. When the target pixel needs moiré compensation, the parameter selector outputs a moiré compensation parameter set of the target pixel located at a memory address of the memory. According to the moiré compensation parameter set stored in the memory address by the memory, the compensation logic operator compensates an original gray value of the target pixel to generate a compensated gray value to drive the target pixel.

The present invention also proposes a method for eliminating moiré defects, which includes: storing the moiré compensation parameter sets of pixels requiring moiré compensation in a pixel matrix in a memory; What is the target pixel; determine whether the target pixel needs moire compensation; when the target pixel needs moiré compensation, output the moiré compensation parameter set of the target pixel at a memory address of the memory; The stored moiré compensation parameter set compensates an original gray value of the target pixel to generate a compensated gray value; and drives the target pixel with the compensated gray value.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, several embodiments are specifically listed below, together with the accompanying drawings.

Description of drawings

Fig. 1 is an embodiment of the image display system of the present invention;

Fig. 2 is another embodiment of the image display system of the present invention;

Fig. 3 is an embodiment of the parameter selector of the present invention;

Fig. 4 shows a mobile phone screen;

Fig. 5 shows how multiple pixels share the same moiré compensation parameter set;

Fig. 6 is another embodiment of the parameter selector of the present invention;

Fig. 7 is another embodiment of the image display system of the present invention; and

FIG. 8 is an embodiment of the method for eliminating moiré defects of the present invention.

Description of main component symbols

102-pixel matrix; 104-memory;

106-parameter selector; 108-compensation logic operator;

110-drive signal; 112-memory address;

114-moiré compensation parameter group; 116-original gray value;

118-Gray value after compensation; 120-External compensation module;

202 - memory module;

302-sequence control circuit; 304-ASIC;

400-mobile phone screen; 402-dynamic image display area;

403-static image display area;

502-pixel matrix; 504-pixels with common parameters;

506 - memory;

602-processing unit; 604-storage medium;

700 - electronic device;

704 - display panel; and 706 - input unit.

Detailed ways

FIG. 1 is an embodiment of an image display system of the present invention, which includes a pixel matrix 102 having a plurality of pixels, a memory 104 , a parameter selector 106 , and a compensation logic operator 108 . The memory 104 stores moiré compensation parameter sets of pixels in the pixel matrix 102 that require moiré compensation. The parameter selector 106 receives the driving signal 110 of the pixel matrix 102 to determine a target pixel to be driven; then, the parameter selector 106 determines whether the target pixel needs moiré compensation. When the target pixel needs moiré compensation, the parameter selector 106 outputs the moiré compensation parameter set of the target pixel at a memory address 112 of the memory 104 . The compensation logic operator 108 corrects an original gray value 116 of the target pixel according to the moiré compensation parameter set 114 stored in the memory address 112 of the memory 104 to generate a compensated gray value 118 to drive the target pixel . In the state where the target pixel does not need moiré compensation, the compensation logic operator 108 will not modify the original gray value 116 . The embodiment of FIG. 1 integrates the parameter selector 106 and the compensation logic operator 108 into an external compensation module 120 .

FIG. 2 is another embodiment of the image display system of the present invention, wherein the parameter selector 106 and the memory 104 are integrated in a memory module 202 .

FIG. 3 is an implementation manner of the parameter selector 106, which includes a timing controller 302 (Timing Controller) and an application specific integrated circuit 304 (ASIC). After receiving the driving signal 110 , the timing controller 302 will determine which target pixel is currently being driven. The ASIC 304 is responsible for determining whether the target pixel needs to be compensated for moiré.

In some implementations, in order to reduce the amount of transmitted data in the memory, the present invention only performs moiré compensation on the color in the pixel matrix 102 to which human eyes are more sensitive—for example, green. The ASIC 304 determines that the target pixel needs to perform moiré compensation only when the color of the target pixel is equal to a specific color (eg, green). In this way, not only the amount of data required to be stored by the memory 104 can be greatly reduced (only the moiré compensation parameter set of the pixel of the specific color needs to be stored), but also the amount of data transmitted by the memory 104 can be greatly reduced. The above-mentioned specific color is not limited to green, and is determined depending on the characteristics of the pixels in the pixel matrix 102 . If the capacity and bandwidth of the memory 104 allow, moiré compensation can also be performed for more than two specific colors at the same time, such as green and white.

In some implementations, in order to reduce the data transmission amount of the memory, the present invention only performs moiré compensation on a specific color in one frame. The ASIC 304 will determine that the target pixel needs moiré compensation in a first frame and the color of the target pixel is equal to a first specific color; and in a second frame and the color of the target pixel is equal to a second For a specific color, it is determined that the target pixel needs moiré compensation. Taking the QVGA image display system as an example, the ASIC 304 will perform moiré compensation for the red sub-pixel in a first frame, perform moiré compensation for the green sub-pixel in a second frame, and perform moiré compensation for the blue sub-pixel in a third frame. The sub-pixels perform moiré compensation, and perform moiré compensation on white sub-pixels in a fourth frame; the present invention performs moiré compensation on sub-pixels of different colors in different frames in turn. Compared with the traditional external compensation technique—compensating all sub-pixels in each frame—the above-mentioned QVGA system reduces the data transmission amount of the memory 104 in each frame by a factor of 1/4, and the power consumption can also be significantly reduced.

In some implementations, in order to reduce the amount of data transmitted by the memory, the present invention separates the odd-numbered row pixels and even-numbered row pixels of the pixel matrix 102 into two frames for compensation. The ASIC 304 determines that the target pixel needs moiré compensation in a first frame and the target pixel is located on an odd row of the pixel matrix 102; and in a second frame and the target pixel is located in an odd row of the pixel matrix 102 When it is on an even-numbered line, it is determined that the target pixel needs moiré compensation. In this way, the data transmission amount of each frame of the memory 104 is reduced by 1/2 times.

In some embodiments, in order to reduce the amount of transmitted data in the memory, the present invention only performs moiré compensation on the static image area. FIG. 4 takes a mobile phone screen 400 as an example, which includes a dynamic image display area 402 and a static image display area 403 outside the dynamic image display area 402 . The static image display area 403 is responsible for displaying fixed images, such as incoming images, mailbox images, battery images, . . . and so on. Since human eyes are more sensitive to moiré defects in static images, the ASIC 304 determines that the target pixel requires moiré compensation only when the target pixel is located in the static image display area. In this way, the memory 104 only needs to store the moiré compensation parameter sets of the pixels in the static image display area, and its capacity does not need to be too large.

In some embodiments, in order to reduce the amount of transmitted data, memory capacity and power consumption of the memory, the present invention compensates for the region where the moiré defect is particularly serious. On the pixel matrix 102, due to process variation and circuit layout characteristics, a certain local area often produces moiré defects that are clearly visible to the human eye. The present invention can determine that the moiré compensation is performed only when the target pixel is located in this area , this approach can not only improve the yield rate of the panel, but also reduce the bandwidth and capacity required by the memory.

In some embodiments, in order to reduce the amount of data transmitted by the memory, the present invention only performs moiré compensation on pixels with a short lifetime (lifetime). On the pixel matrix 102 , due to reasons such as circuit layout, pixel characteristics, etc., some areas have a shorter life cycle, and the luminous ability gradually deteriorates. These areas are called fast life cycle decay areas. The ASIC 304 will determine that the target pixel needs moiré compensation when the target pixel is located in the lifetime fast decay region.

In some implementations, multiple pixels of the pixel matrix 102 share the same moiré compensation parameter set. Therefore, the amount of parameters to be stored in the memory 104 is greatly reduced, and the data transmission amount of the memory 104 is also reduced accordingly. Taking FIG. 5 as an example, multiple pixels in the pixel matrix 502 (indicated by the area 504 ) share the same moiré compensation parameter set, and its value is stored at a memory address of the memory 506 .

FIG. 6 is another implementation manner of the parameter selector 106 . Compared with FIG. 3 , the ASIC 304 can be replaced by a processing unit 602 and a storage medium 604 . The actions performed by the ASIC 304 can be changed to a software. The software is stored on the storage medium 604 and accessed by the processing unit 602 .

Fig. 7 is an embodiment of the present invention. A display panel 704 includes the aforementioned pixel matrix 102 , memory 104 , parameter selector 106 , and compensation logic operator 108 . The display panel 704 can be installed in an electronic device 700 . As shown in the figure, the electronic device 700 includes a display panel 704 and an input unit 706 . The input unit 706 is coupled to the display panel 704 for receiving image frames to be displayed on the display panel 704 . The electronic device 700 can be a mobile phone, a digital camera, a personal digital assistant, a mobile computer, a desktop computer, a television, an automotive display, a digital photo frame, an aviation display or a Portable CD player...etc.

The invention also discloses a method for eliminating moiré defects. Refer to the flow chart shown in Figure 8 for a step-by-step description. Step S802 is to store moiré compensation parameter sets of pixels requiring moiré compensation in a pixel matrix in a memory. Step S804 , according to the driving signal of the pixel matrix, it is determined what a target pixel is to be driven. Step S806 determines whether the target pixel needs moiré compensation. When the target pixel needs moiré compensation, step S808 is executed to output the moiré compensation parameter set of the target pixel at a memory address of the memory. Step S810 corrects an original gray value of the target pixel according to the moiré compensation parameter set stored in the memory address in the memory to generate a compensated gray value. Step S812 drives the target pixel with the compensated gray value. On the contrary, if the target pixel does not need moiré compensation, step S814 is executed to drive the target pixel with the original gray value.

The present invention also provides several rules for judging whether the target pixel needs moiré compensation. In some embodiments, the present invention determines that the target pixel needs moiré compensation when the color of the target pixel is equal to a specific color. In some embodiments, the present invention determines that the target pixel needs moiré compensation in a first frame and when the color of the target pixel is equal to a first specific color; and in a second frame and the color of the target pixel is equal to When a second specific color is used, it is determined that the target pixel needs moiré compensation. That is, at least one color is sequentially compensated within different frame times. In some embodiments, the present invention determines that the target pixel needs moiré compensation in a first frame and the target pixel is located on an odd row of the pixel matrix; and in a second frame and the target pixel is located in the pixel When it is on the even row of the matrix, it is determined that the target pixel needs moiré compensation. In some embodiments, the present invention determines that the target pixel needs moiré compensation when the target pixel is located in a static image display area. In some embodiments, the present invention determines that the target pixel needs moiré compensation when the target pixel is located in a fast lifetime decay region.

In addition, the method for eliminating moiré defects provided by the present invention further includes allowing multiple pixels in the pixel matrix to share the same moiré compensation parameter set, so as to reduce the capacity of the memory and the amount of data transmission.

The technology disclosed in the present invention can use common speed memory in the market to achieve moiré compensation for images with high resolution and high screen update speed, without special use of high-speed memory. Therefore, the cost of the memory can be controlled within a reasonable range.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the protection scope of the present invention shall be determined by the scope of the appended claims.

Claims (18)

1. image display system, comprising:

One picture element matrix;

One storer is stored the moire compensating parameter group of the pixel that needs to carry out the moire compensation in this picture element matrix;

One selection of parameter device, why receive a object pixel that the drive signal of this picture element matrix judge is ready to drive, and judge that moire compensating parameter group that whether this object pixel needs the moire compensation and export this object pixel when this object pixel needs the moire compensation is positioned at a storage address of this storer; And

One compensation logic arithmetical unit, a moire compensating parameter group of storing in this storage address according to this storer and an original gray value of this object pixel produce a compensation back gray-scale value and write this object pixel.

2. image display system as claimed in claim 1, wherein this selection of parameter device comprises a special IC, when the color of this object pixel equals a particular color, judges that this object pixel needs the moire compensation.

3. image display system as claimed in claim 1, wherein this selection of parameter device comprises a special IC, when the color of one first frame and this object pixel equals one first particular color, judges that this object pixel needs the moire compensation; And when the color of one second frame and this object pixel equals one second particular color, judge that this object pixel needs the moire compensation.

4. image display system as claimed in claim 1, wherein this selection of parameter device comprises a special IC, when one first frame and this object pixel are positioned on the odd-numbered line of this picture element matrix, judges that this object pixel needs the moire compensation; And when one second frame and this object pixel are positioned on the even number line of this picture element matrix, judge that this object pixel needs the moire compensation.

5. image display system as claimed in claim 1, wherein this selection of parameter device comprises a special IC, when this object pixel is positioned at a still image viewing area, judges that this object pixel needs the moire compensation.

6. image display system as claimed in claim 1, wherein this selection of parameter device comprises a special IC, is positioned at a cloud pattern defects comparatively serious when zone in this object pixel, judges that this object pixel needs moire to compensate.

7. image display system as claimed in claim 1, wherein this selection of parameter device comprises a special IC, is positioned at a life cycle during quick attenuation region in this object pixel, judges that this object pixel needs the moire compensation.

8. image display system as claimed in claim 1, the wherein shared same moire compensating parameter group of a plurality of pixels in this picture element matrix.

9. image display system as claimed in claim 1, wherein this selection of parameter device comprises a processing unit and a medium, this medium is stored a software in order to judge whether this pixel needs the moire compensation.

10. image display system as claimed in claim 1 also comprises an electronic installation, comprising:

One display pannel is comprising above-mentioned picture element matrix, this storer, this selection of parameter device and this compensation logic arithmetical unit; And

One input block couples this display pannel, desires the picture frame that shows with this display pannel with reception.

11. image display system as claimed in claim 10, wherein this electronic installation is a mobile phone, a digital camera, a personal digital assistant, a removable computer, a desktop computer, a televisor, an automobile with display, a digital photograph photo frame, an aviation with a display or a portable disc player.

12. a method for eliminating moire defect, comprising:

The moire compensating parameter group of storing the pixel that needs the moire compensation in the picture element matrix is in a storer;

According to the drive signal of this picture element matrix, the object pixel that judgement will just drive why;

Judge whether this object pixel needs the moire compensation;

When this object pixel needed the moire compensation, the moire compensating parameter group of exporting this object pixel was positioned at a storage address of this storer;

A moire compensating parameter group of storing in this storage address according to this storer and an original gray value of this object pixel produce a compensation back gray-scale value; And

Drive this object pixel with this compensation back gray-scale value.

13. method for eliminating moire defect as claimed in claim 12 when the color that wherein also is included in this object pixel equals a particular color, judges that this object pixel needs the moire compensation.

14. method for eliminating moire defect as claimed in claim 12 when the color that wherein also is included in one first frame and this object pixel equals one first particular color, judges that this object pixel needs the moire compensation; And when the color of one second frame and this object pixel equals one second particular color, judge that this object pixel needs the moire compensation.

15. method for eliminating moire defect as claimed in claim 12 wherein also is included in one first frame and this object pixel when being positioned on the odd-numbered line of this picture element matrix, judges that this object pixel needs the moire compensation; And when one second frame and this object pixel are positioned on the even number line of this picture element matrix, judge that this object pixel needs the moire compensation.

16. method for eliminating moire defect as claimed in claim 12 wherein also is included in this object pixel when being positioned at a still image viewing area, judges that this object pixel needs the moire compensation.

17. method for eliminating moire defect as claimed in claim 12 wherein also is included in this object pixel and is positioned at a life cycle during quick attenuation region, judges that this object pixel needs the moire compensation.

18. method for eliminating moire defect as claimed in claim 12 wherein also comprises making the shared same moire compensating parameter group of a plurality of pixels in this picture element matrix.

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