CN101154373A - Storage structure and method for over-driving image data - Google Patents

Abstract

A storage technique of over-drive image data is to divide the image data into non-image data and image data, which are stored in a non-image data storage area and an image data storage area in a memory unit respectively. Wherein, the three primary color data of the non-image data are directly stored in the image data storage area; the three primary color data of the image data are converted into YCbCr data, the current three primary color data and the three primary color data of the previous picture frame are compared through a lookup table to obtain overdrive YCbCr data, then the YCbCr data and the overdrive YCbCr data are compressed, sampled and combined according to a video communication compression standard, and then are stored in an image data storage area, and the requirement of an overdrive technology on an internal memory is reduced.

Description

Storage structure and method of overdrive image data

technical field

The invention relates to a display image data storage technology, in particular to a graphic data overdrive storage device and its method, which are used to reduce the demand for storage memory size.

Background technique

Due to the thin, light and small characteristics of liquid crystal displays and lower power consumption than traditional CRT displays, liquid crystal displays have gradually replaced CRT displays in recent years.

Liquid crystal is an organic compound with neutral properties between liquid and crystal, and its color or light transmission can be changed by voltage or temperature. The configuration of a traditional liquid crystal display includes: a liquid crystal panel, and a driving circuit connected to the liquid crystal panel, wherein the driving circuit includes a grayscale voltage generating circuit.

A liquid crystal panel is composed of a plurality of gate lines and a plurality of data lines connected to each other perpendicularly to the gate lines. Each pixel is composed of a thin film transistor (TFT), a storage capacitor and a liquid crystal capacitor. Each pixel of the liquid crystal panel also includes three sub-pixels corresponding to the three primary colors of red (R), green (G) and blue (B). The pixels displayed on the LCD panel are obtained by combining R, G and B color filters, which can not only display color pictures, but also display pure red, green, blue and gray scale. The TFT functions as a switch, its gate is electrically connected to the gate line and controlled by the gate drive circuit; its source is electrically connected to the data line and controlled by the source drive circuit. The gray-scale voltage generation circuit is connected to the source drive circuit to generate gray-scale voltage or gray-scale reference voltage, which is a reference for generating liquid crystal driving voltage.

The operation mode of the liquid crystal display is that the gate drive circuit sequentially scans the pixels of each row of the panel. After the gray scale reference voltage is output from the gray scale voltage generation circuit, the source drive circuit generates liquid crystal according to the input R, G, and B timing data. driving voltage. Then, the source driving circuit operates to apply the generated liquid crystal driving voltage to the panel every scan.

Due to the fact that liquid crystal displays tend to be high-speed with the development of the industry, the existing method is to increase the filling speed of the storage capacitor and the liquid crystal capacitor in the pixel to increase its driving speed. This is because if the voltage applied from the source drive circuit has a high value, the storage capacitor and the liquid crystal capacitor will be charged quickly to improve the overall drive circuit of the LCD.

Please refer to FIG. 1 , which is a schematic diagram of the gray scale voltage of the input/output of the overdrive. The output gray value 2 displayed by the pixels on the panel is not only based on the input gray value 1 of the original image data, but also generated by using the lookup table or conversion method using the gray voltage of the previous frame. The output gray value of the voltage is 2. Overdrive technology (overdrive technology) is to increase the gray value of the image data, speed up the TFT response time (response time), and make the screen transition smoother through a shorter response time. For example, the original input gray value data can make the brightness of the panel reach B21 in 16.6ms, while the overdrive can increase the brightness of the panel to B31 in 16.6ms, thereby speeding up the TFT response time and the liquid crystal inversion time to make screen transitions smoother.

Also because of the overdrive technology, the memory capacity of the drive element needs to be doubled to store the original image data and the overdrive image data respectively. It is generally used in the driving components of mobile phone display devices. The traditional method is to use the asynchrony between the input of image data on the display panel and the pixel scanning, and add an additional memory to the driving circuit, so that the overdrive image data can be stored in the drive circuit. Additional memory can increase the gray value of the original input image data, speed up the pixel response time, and make the screen transition smoother.

The current overdrive method requires additional memory in the drive circuit, thereby increasing the memory capacity. However, this method will indeed cause a large demand for the memory capacity of the display product, increase the manufacturing cost, and increase the space required by the driving circuit.

Contents of the invention

In order to solve the above-mentioned technical problems, the object of the present invention is to provide a storage method for overdriven image data, which converts the three primary color data of the image data in the frame data into YCbCr data, and replaces the overdriven three primary color data with overdriven YCbCr data, and the two YCbCr data are compressed, sampled and combined according to the video information compression standard, which reduces the memory demand of the display driver controller using the overdrive technology and reduces the memory cost.

In order to achieve the above-mentioned purpose, according to a data storage method for a drive controller of a display according to the present invention, the image data is divided into non-image data and image data, and are stored in the non-image data storage area and the image data in the internal memory unit respectively. Image data storage area. Wherein, the three primary color data of the non-image data are directly stored in the image data storage area; the three primary color data of the image data are converted into YCbCr data, and the three primary color data of the image data and the three primary color image data of the previous frame are compared through a query table, and converting the compared three primary color data into overdrive YCbCr data; and compressing, sampling and combining the YCbCr data and the overdrive YCbCr data according to the video image compression standard, and storing them in the image data storage area.

Because the meaning represented by Y is brightness (luminance), and the meaning represented by Cb and Cr is chroma (chrominance), the present invention aims at the Y component that has the greatest influence on human eyes, and then stores it in the In the memory module, reduce the size of the memory unit required to drive the controller.

The realization of the method of the present invention is to change the storage structure in the drive controller of the display. The storage structure of the present invention includes: a memory unit, which is internally divided into a non-image data storage area and an image data storage area; the first multiplexer, which has Two input terminals, one input terminal is used to access the non-image data of the three primary colors (RGB) of the image frame, and output the data to the non-image data storage area; the first conversion unit is connected to the current image frame (frame N) The image data of the three primary colors (RGB), and convert the three primary colors data into YCbCr data; and the second conversion unit compares the three primary colors of the current image frame (frame N) and the previous frame (frame N-1) by a lookup table image data, and convert the compared overdrive three primary colors (R'G'B') data into overdrive YCbCr data (Y'Cb'Cr'); the data encoding unit is used to access the YCbCr output from the first conversion unit data, and the overdrive YCbCr data output by the second conversion unit, the two data are compressed, sampled and combined according to the video information compression standard; then the combined data is input to the other input end of the first multiplexer, through the first The multiplexer transmits to the image data storage area. Wherein, the compressed sampling is selected from one of the sampling calculation rules of Y:Cb:Cr=4:2:2, Y:Cb:Cr=4:2:0 and Y:Cb:Cr=4:1:1 .

In addition, the image data of the three primary colors of the previous frame (frame N-1) is the YCbCr data and the overdrive YCbCr data of the previous frame in the image data storage area, and is passed through the data decoding unit according to the previous original video information compression standard Decompressing, and then converting the YCbCr data into the image data of the three primary colors of the previous frame through the first conversion unit to the look-up table.

Wherein, the stored data of the memory unit is connected to the data in the non-image data storage area through the input end of the second multiplexer; Another input terminal of the second multiplexer; thus, the second multiplexer transmits non-image data and image data to the display element.

To sum up, the method for storing overdrive image data of the present invention can reduce the demand for memory of the display driver controller using the overdrive technology, and reduce the cost of the memory.

Description of drawings

FIG. 1 is a schematic diagram of gray-scale voltages of overdriven input/output.

Fig. 2 is a schematic diagram of the storage structure of the present invention.

FIG. 3 is a schematic diagram of image data divided into non-image data and image data.

FIG. 4 is a schematic diagram of image data storage in the present invention.

Detailed ways

Relevant detailed content and technical specification of the present invention, now coordinate drawing description as follows:

The various colors seen by human eyes are caused by different wavelengths of light. It has been found through experiments that the human naked eye has a particularly strong perception of three wavelengths. As long as the intensity of these three kinds of light is properly adjusted, human beings can feel "Almost" all colors. These three colors are called the three primary colors of light (RGB), which are red (red), green (green), and blue (blue). All color TV sets and screens have light-emitting devices that generate these three basic lights. Because the mixture of these three kinds of light can represent almost all colors, the computer uses the digital data value of the three primary colors (RGB) to mark the color. Each color is recorded with 8bits, which can range from 0 to 255, a total of 256 There are more than 16 million changes in three kinds of brightness changes, which is also the 24bit full color we often hear.

The Y data in YCbCr data is the gray scale value or brightness value converted from color to gray scale image, and its conversion formula is mainly based on the different sensitivities of human eyes to the three primary colors (RGB) of red, green and blue. , where the larger the value, the more sensitive the human eye is to the color, so the sensitivity of the three colors is green (0.587), red (0.299), and blue (0.114). Therefore, the conversion and calculation relationship of the general three primary colors (RGB) data into YCbCr data is as follows:

Y＝0.299R+0.587G+0.114B

Cb=-0.168R-0.331G-0.499B

Cr＝0.500R-0.419G-0.081B

The conversion and calculation relationship of YCbCr data into three primary colors (RGB) data is as follows:

R=Y+104020 (Cr-128)

G=Y-0.3441(Cb-128)-0.7141(Cr-128)

B=Y+107720(Cb-128)

Although human eyes are more sensitive to low-frequency data than high-frequency data, in fact human eyes are much more sensitive to changes in brightness than to changes in color. Therefore, in the application of displays, generally speaking, only grayscale and full-color images are processed. Full-color images are composed of three color components (components) Y, Cb, and Cr, while grayscale images Since there is only brightness but no color, there is only one component of Y data. Because the meaning represented by Y data is brightness, and the meaning represented by Cb and Cr is chroma data, that is to say, the data of Y data is more important.

Please refer to FIG. 2 , which is a schematic diagram of the storage structure of the present invention. The present invention is mainly aimed at the above principles, so the aforementioned storage structure is proposed. The present invention is a storage structure arranged in the drive controller of the display, including: a memory unit 15, which is internally divided into non-image data storage areas 151 and image data storage area 152; through the first multiplexer 11 with two input ends, the input end accesses the non-image data of the three primary colors (picture frame N) of the current image frame, and output data to the non-image data storage area 151 ; and the other input terminal is used to receive the converted and combined image data, and transmit the image data to the image data storage area 152 of the memory unit 15 .

Before the image data is stored, it is transmitted to the first conversion unit 131, and the first conversion unit 131 accesses the image data of the three primary colors RGB (frame N) of the current image frame, and converts the three primary colors RGB data into YCbCr data and the second conversion unit 132 compares the original image data of the three primary colors of the current image frame and the previous frame through the lookup table 12, and converts the compared overdrive three primary color data R'G'B' into overdrive YCbCr data Y 'Cb'Cr'; then, the data encoding unit 141 is used to access the YCbCr data output by the first conversion unit 131, and the overdrive YCbCr data Y'Cb'Cr' output by the second conversion unit 132, and the two data are converted according to Video information compression standard (MPEG: Motion Pictures Expert Group) compressed sampling and combination, wherein the compressed sampling is selected from Y:Cb:Cr=4:2:2, Y:Cb:Cr=4:2:0 and Y One of the sampling calculation rules of: Cb:Cr=4:1:1; and the combined data is input to the other input end of the first multiplexer 11, and is transmitted to the image data through the first multiplexer 11 storage area 152 .

Wherein, the image data of the three primary colors of the previous frame (frame N-1) is the original YCbCr data of the previous frame in the image data storage area 152, decompressed by the data decoding unit 142 according to the original video information compression standard, and then passed The third conversion unit 133 converts the YCbCr data into the image data of the three primary colors of the previous frame.

Please refer to FIG. 3 again, which is a schematic diagram of image data divided into non-image data and image data. The non-image data storage area 151 in the memory unit 15 is used to store the non-image three primary color data R, G, B in the original image frame; and the image data storage area 152 stores the compressed sampling of the original image data in the current image frame. YCbCr data, and overdrive YCbCr data Y'Cb'Cr' that is compressed and sampled after overdrive. If the sampling compression of Y:Cb:Cr=4:1:1 (4:2:0) is performed, the original compressed YCbCr data and a group of CbCr data used for the Y data of four pixels will be stored Previously, the overdriven YCbCr data Y'Cb'Cr' that is overdriven will be used for the Y' data of four pixels, and the data will be stored thereafter.

Please refer to FIG. 4 again, which is a schematic diagram of image data storage in the present invention. Taking the 4×4 pixels of the display as an example, after the image data of the original image frame is sampled and compressed by Y:Cb:Cr=4:1:1 (4:2:0), four groups of images are stored in the image data storage area 152 The original compressed and sampled YCbCr data, and four sets of compressed and sampled YCbCr data Y'Cb'Cr' after overdrive. Therefore, in addition to storing four original compressed and sampled YCbCr data in the image data storage area 152, four sets of overdriven YCbCr data Y'Cb'Cr' are also stored, and only the original data and the overdriven data are compressed and sampled. , by increasing the grayscale value of the image data, the TFT response time and the liquid crystal inversion time are accelerated, so that the screen transition is smoother. At the same time, compressing and sampling the original data and the overdrive data also reduces the demand for memory of the display driver controller using the overdrive technology, and reduces the cost of the memory.

Moreover, the data stored in the memory unit 15 is then connected to the three primary colors (RGB) data of the non-image data storage area 151 through the input end of the second multiplexer 17; The data converted into three primary colors (RGB) is output to the other input end of the second multiplexer 17 ; thus, the second multiplexer 17 scans and outputs the non-image data and image data to the display element 20 .

The present invention proposes a method for storing overdrive image data. In the method of the present invention, the image data is divided into non-image data and image data, and stored in the non-image data storage area 151 and the image data storage area inside the memory unit 15 respectively. 152. Wherein, the three primary colors (RGB) data of the non-image data are directly stored in the image data storage area 151; and the three primary colors data of the image data are converted into YCbCr data, and the three primary colors data of the image data and the previous frame are compared by the lookup table 12 image data of the three primary colors, and convert the compared three primary color data into overdrive YCbCr data Y'Cb'Cr'; and compress, sample and combine the YCbCr data and the overdrive YCbCr data according to the video information compression standard, and store them in the image data storage area 152 .

Take the image frame of 4*4 groups of three primary colors RGB data as an example (as shown in Figure 4), in the overdrive mode of the prior art, the memory capacity is divided by the original 16*3=48 bits to store the original three primary colors RGB data , the memory capacity of the same size (16×3=48 bits) is also required to store the overdriven three-primary color R'G'B' data, so when the display uses the overdrive technology, it needs twice the original memory capacity, It is used to store original image data and overdrive image data respectively. A total of 96 bits are required to store image data of overdrive technology.

And the present invention converts the three primary colors (RGB) data into YCbCr data first, and then passes through such as Y: Cb: Cr=4: 2: 2 (2: 1: 1) or Y: Cb: Cr=4: 1: 1 (4: 2: 0) sampling compression of one of the sampling ratios, taking the sampling compression of Y: Cb: Cr = 4: 1: 1 (4: 2: 0) as an example, the four Y data share the same A set of Cb and Cr data; and the overdrive image data (Y'Cb'Cr') also has four Y' data sharing the same set of Cb' and Cr' data. Therefore, the storage required size of the overdrive image data of the present invention will be as shown in Figure 4, only needing the same 48-bit memory space as no overdrive drive mode is enough, so the same image data will be larger than the overdrive of the prior art. Drive mode saves half of the storage space.

The present invention converts the original three primary color data and the overdrive three primary color data of the image data in the frame data into YCbCr data format respectively, and compresses and samples according to the video information compression standard, and then stores it in the memory of the drive controller of the display, thereby effectively Reduce the demand for memory capacity, reduce the memory storage space requirements of the overdrive mode, and store the image data of the overdrive with the original memory space, reducing the cost of memory production.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. In the above-described embodiments, various modifications and changes are possible to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. the memory structure of an overdrive image data is the interior memory structure of driving governor that is arranged at display, it is characterized in that, comprising:

Internal storage location (15), it is divided into non-image data storage area (151) and image data storage area (152);

First multiplexer (11) has two input ends, and an input end is used for the trichromatic non-image data of incoming image picture frame, and output data is to described non-image data storage area (151);

First converting unit (131), the trichromatic image data of incoming image picture frame, and the three primary colors data-switching become the YCbCr data;

Second converting unit (132), it is by enquiry form (12) the trichromatic image data of current images picture frame and last picture frame relatively, and the one-tenth of the three primary colors data-switching after will the comparing YCbCr data of overdriving;

Digital coding unit (141) in order to insert the YCbCr data of first converting unit (131) output, reaches the YCbCr data of overdriving of second converting unit (132) output, with two data based video communication compression standards compression sampling and combinations; And in conjunction with data be input to another input end of described first multiplexer (11), reach described image data storage area (152) by described first multiplexer (11).

2. memory structure according to claim 1, it is characterized in that, the trichromatic image data of last picture frame is the original YCbCr data of last picture frame in the image data storage area (152), by data decoding unit (142) according to former video communication compression standard decompress(ion); By the 3rd converting unit (133), the YCbCr data-switching is become the trichromatic image data of last picture frame again.

3. memory structure according to claim 1 is characterized in that, the storage data of described internal storage location (15) inserts the data of described non-image data storage area (151) by the input end of second multiplexer (17); And

Decompress(ion) converting unit (16) converts the data decompression of described image data storage area (152) to the three primary colors data and transports to another input end of described second multiplexer (17); By described second multiplexer (17) non-image data and image data are reached display element (20).

4. memory structure according to claim 1 is characterized in that, described compression sampling is to select from Y: Cb: Cr=4: 2: 2, Y: Cb: Cr=4: 2: 0 and Y: Cb: Cr=4: wherein a kind of sampling calculation rule of 1: 1.

5. the storage method of an overdrive image data is the data storage method for the driving governor of display, it is characterized in that described method comprises:

View data is divided into non-image data and image data, and is stored in internal storage location (15) inner non-image data storage area (151) and image data storage area (152) respectively;

Wherein, the three primary colors data of described non-image data directly are stored in image data storage area (152);

The three primary colors data-switching of described image data becomes the YCbCr data, and by the three primary colors data of the more described image data of enquiry form (12) and the trichromatic image data of last picture frame, with the YCbCr data that become to overdrive of the three primary colors data-switching after the comparison, again YCbCr data and the data based video communication compression standard compression of the YCbCr that overdrives are taken a sample and combination, and be stored in image data storage area (152).

6. storage method according to claim 5 is characterized in that, described compression sampling is to select from Y: Cb: Cr=4: 2: 2, Y: Cb: Cr=4: 2: 0 and Y: Cb: Cr=4: wherein a kind of sampling calculation rule of 1: 1.

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