TW201349881A - Digital image processing system and its method - Google Patents

Abstract

This invention discloses a digital image processing system and its method about the real-time compensation of uniformity of the LCD monitor, comprised a coefficient computing unit, a coefficient buffer unit, a data input unit, a computing unit (Digital Uniformity Compensation, DUC), and a data output unit. The provision of the digital image with this processing method and the digital image processing system will efficiently achieve every sub-pixel paralleled with its processing operation to make the image uniformize up from 70% to 95% in the context of brightness without sacrificing too much luminance.

Description

Digital image processing system and digital image processing method

The invention relates to a digital image processing system and a digital image processing method, in particular to a digital image processing system and a digital image processing method for instantly compensating for the uniformity of a liquid crystal screen.

With the development of human technology, mobile phones, TVs, desktop computers, notebook computers, etc. are all in the category of display devices, and important components in display devices are displays, so how to make the display It has been a long time to show that the light is softer or more suitable for human eyes, and has a better visual effect. However, this topic has always occupied a large part of relevant research and development content.

Among them, the monochrome display for medical use focuses on displaying image sharpness and resolution. The brightness uniformity of the medical display is closely related to the gray level of the real image. If the brightness is uneven, the screen contrast will be uneven. Moreover, this difference will further cause the DICOM Curve to be inaccurate. The initial display uniformity is affected by the backlight, the filter, etc., and the brightness uniformity is mostly about 70%. The brightness uniformity calculation adopts the maximum brightness of the display minus the minimum brightness of the display. The obtained value is divided by the position of the central point of the display to measure the brightness, that is, the brightness difference degree value is obtained, and the difference value provided by the general manufacturer is less than 30%, and the brightness uniformity is more than 70%.

The implementation of related prior art techniques can be broadly divided into several categories, but all have missing points to be improved. One is to divide the display into several areas, but this method is easy to mosaic. The second is to compensate the brightness by linear interpolation, but this method is easy to make the uniformity not smooth.

The present invention is based on the above prior art and further display image processing, with sub-pixel as a reference unit, so that the display display uniformity performance can be as high as 95%.

The invention also solves the problem of displaying brightness in the prior art, and generally the brightness of the desktop computer is about 300nits, notebook computer brightness is about 200nits, and 8bit panel, the maximum display grayscale value is 255, between adjacent grayscale values, for example: grayscale values between 254 and 255 contrast is not obvious, the human eye can not be obvious The area is separated, that is, the visual effect is better, and the long-term viewing is less harmful, but if the brightness is increased to 1000 nits, the gray-scale difference value will be conspicuous due to the contrast increase, that is, the brightness is increased, the gray level The difference value is enlarged, but it hinders the human eye from viewing. The present invention also wants to deal with such a problem that the contrast value of the gray scale difference is obvious due to excessive brightness.

In order to solve the above problems, a main object of the present invention is to provide a digital image processing system for compensating for the uniformity of a liquid crystal screen and a processing method thereof, which mainly include: a coefficient operation device, a coefficient temporary storage device, a data input device, and a processing device. Digital Uniformity Compensation (DUC) and a data output device, through the digital image processing system and the processing method thereof provided by the present invention, can improve image uniformity from 70% to 95 without sacrificing too much brightness. %, increase the uniformity of image display, more suitable for long-term viewing.

Another main object of the present invention is to provide a digital image processing system and a processing method thereof, including a coefficient operation device for performing parallel processing operations for each sub-pixel (Sub-pixel), which can simultaneously process the total amount of operations at a time. Speed up processing, can effectively improve the processing efficiency.

Another main object of the present invention is to provide a digital image processing system and a processing method thereof, which, after the data output device, further includes a dithering device, which can be used for the data after the uniformity compensation formula Further image processing is performed for all digital driving levels (DDL) to make the image display more uniform, visually better, and more suitable for human viewing.

According to the above object, the present invention provides a digital image processing system for compensating for uniformity of a liquid crystal screen, comprising: a coefficient operation device for calculating a plurality of coefficients and a coefficient temporary storage device according to a plurality of point brightness values, for storing a plurality of coefficients Coefficients, an image input device for transmitting and inputting image signals, the image signal is composed of a plurality of pixels, each pixel includes a plurality of sub-pixels and each sub-pixel has a digital image hierarchy, an arithmetic device, After reading a plurality of coefficients from the coefficient temporary storage device, calculating a plurality of coefficients with a uniformity compensation formula S ( x _i ) to calculate a compensation value for each sub-pixel, and a data output device for The compensation value of each sub-pixel is multiplied by the digital image level of each sub-pixel and output to the screen.

According to the above object, the present invention further provides a digital image processing method for compensating for uniformity of a liquid crystal screen, wherein the digital image processing method comprises: providing a coefficient operation device, calculating a plurality of coefficients according to a plurality of point brightness values, and providing a coefficient temporarily The storage device is configured to store a plurality of coefficients and provide an image input device for transmitting and inputting an image signal. The image signal is composed of a plurality of pixels, each pixel includes a plurality of sub-pixels and each of the sub-pixels has A digital image hierarchy, providing an arithmetic device, after reading a plurality of coefficients from the coefficient temporary storage device, computing a plurality of coefficients with a uniformity compensation formula S ( x _i ) to calculate each sub-pixel The compensation value is provided, and a data output device is provided for multiplying the compensation value of each sub-pixel by the digital image level of each sub-pixel and outputting to a screen.

The digital image processing system and the processing method thereof provided by the invention can effectively process the parallel processing for each sub-pixel, which is beneficial to speed up the processing speed, and the image uniformity can be improved from 70% to 95% without sacrificing too much brightness. And after the data output device, further comprising a dithering device, which can perform further image processing for all digital image layers, so that the output image has better visual effect and is more convenient for human eyes to view.

The present invention mainly discloses a digital image processing system and a digital image processing method for a medical image specification (DICOM, AAPM-TG18), wherein the basic structure and function of the digital image processing system and the digital image processing method have been related technical fields. It is clear to those skilled in the art that the following description is directed only to the digital image processing system and digital image of the present invention. The details of the processing method are described in detail. At the same time, the drawings referred to in the following text are indicative of the structure related to the features of the present invention, and therefore are not drawn according to actual dimensions, and are described first.

First, please refer to FIG. 1 , which is a schematic diagram of a system according to a first embodiment of a digital image processing system of the present invention, comprising: a coefficient computing device 10 , which can be a PC or a barebone system, and is a brightness sensor (Light sensor). 101 measures a plurality of point brightness values, calculates a plurality of coefficients by using the complex point brightness values for subsequent calculation of the compensation value, and a coefficient temporary storage device 20 for storing a plurality of coefficients, in this embodiment, The coefficient temporary storage device can be a memory (Memory) and an image input device 30 for transmitting and inputting an image signal 301. The image signal 301 is composed of a plurality of pixels, and each pixel includes a plurality of sub-pixels. The sub-pixels may be RGB of color image signals (where: R is red-red; G is green-green; B is blue-blue) or LCR of monochrome image signals ( Where: L is a left-left; C is a medium-center; and R is a right-right, and each sub-pixel has a digital image hierarchy. When the digital image hierarchy is 8 bits, the single Color shadow The signal 301 is 0~255 steps; if it is 10bit, the monochrome image signal 301 is 0~1023 steps, and an arithmetic device 40, after reading a plurality of coefficients from the coefficient temporary storage device 20, the plurality of coefficients are uniformly The degree compensation formula S ( x _i ) is operated to calculate the compensation value of each sub-pixel, and a data output device 50 is configured to compare the compensation value of each sub-pixel with the digital image level of each corresponding sub-pixel. After being multiplied and output to the screen, after being processed by the digital image processing system 1 provided by the present invention, the brightness uniformity can be effectively improved to over 95%, and the problem of difference in display brightness can be solved.

Next, please refer to FIG. 2, which is a schematic diagram of image signals of the digital image processing system of the present invention. In the present invention, each pixel 302 includes a plurality of sub-pixels 303, wherein the sub-pixels 303 can be RGB of color image signals (where: R is red-red; G is green-green; and B is blue-blue) Any of the sub-pixels 303 is either LCR of a monochrome image signal (where: L is a left-left; C is a medium-center; and R is a right-right). Therefore, in the present invention, the three sub-pixels 303 are used as the minimum display unit, and processing operations can be performed for each sub-pixel (Sub-pixel) to speed up the processing and effectively improve the processing performance.

Then, the technical features of the present invention are specifically described. The following is a calculation method of the uniformity compensation formula S ( x _i ) of the present invention, wherein the uniformity compensation formula is: S ( x _i )= a ₁ ×( x _i - x _o ) ⁰ + a ₂ ×( x _i - x _o ) ¹ + a ₃ ×( x _i - x _o ) ² + a ₄ ×( x _i - x _o ) ³ +...+ a _n ×( x _i - x _o ) ⁿ , where a ₁ , a ₂ , a ₃ , a ₄ ... a _n is any real number, and x _o is the interpolation start position of one sub-pixel 303, and x _i is the sub-pixel to be interpolated 303 position, please refer to FIG. 3, which is a schematic diagram of the cubic non-linear uniformity compensation formula S ( x _i ) operation flow of the present invention, and in each step (Step), it can be seen that each coefficient is (For example: a ₁ , a ₂ , a ₃ , a ₄ ) The simultaneous operation is performed simultaneously, and the process can be stated as follows according to Figure 3:

Step 1: coefficients a _1, a _2, a _{3. 4} and simultaneously into a calculates, at this time after a zero power into _an item value of _{a 1 × (x i - x} o) 0, a 2 is After the primary term is brought in, the value is a ₂ ×( x _i - x _o ) ¹ , and a ₃ is the quadratic term. The value is a ₃ ×( x _i - x _o ) ¹ , and a ₄ is the cubic term. The value after taking in is a ₄ ×( x _i - x _o ) ¹ , and then proceeds to step 2.

Step 2: Since a ₁ is a zero-order term, the value is not processed after it is taken. a ₁ ×( x _i - x _o ) ⁰ , a ₂ is a square term, so the value is not processed after it is taken. a ₂ ×( x _i - x _o ) ¹ , a ₃ is a quadratic term, so this step needs to be multiplied by ( x _i - x _o ) ¹ , a ₄ is a cubic term, so this step needs to be multiplied ( x _i - x _o ) ¹ , then proceed to step 3.

Step 3: Since a ₁ is a zero-order term, the value is not processed after it is taken. a ₁ ×( x _i - x _o ) ⁰ , a ₂ is a square term, so the value is not processed after it is taken. a ₂ ×( x _i - x _o ) ¹ , a ₃ is a quadratic term multiplied by ( x _i - x _o ) ¹ in step 2, so the value becomes a ₃ ×( x _i - x _o ) ² , a ₄ is a cubic term, so this step needs to be multiplied by ( x _i - x _o ) ¹ , and then proceeds to step 4.

Step 4: Because it is a ₁ entry into the zero power value after treatment is still not _{a 1 (x i - x o} ) 0, a 2 is a side entry into the value it remains a treatment nor do ₂ ( x _i - x _o ) ¹ , a ₃ is a quadratic term, so the value is not processed after it is still a ₃ ×( x _i - x _o ) ² , a ₄ is a cubic term which is multiplied in step 3. Upper ( x _i - x _o ) ¹ so the value becomes a ₄ ( x _i - x _o ) ³ . After the above four steps, the operation result is S ( x _i )= a ₁ ×( x _i - x _o ) ⁰ + a ₂ ×( x _i - x _o ) ¹ + a ₃ ×( x _i - x _o ² + a ₄ ×( x _i - x _o ) ³ , the above is the parallelness calculation formula S ( x _i ) of the present invention. The parallel processing method can effectively improve the processing speed and speed up the processing. The time of the processing.

A practical case is illustrated as follows: for example, there is a 5M panel with a resolution of 2560×2048 and a coefficient value of 2048 groups. The coefficients of each line in the panel are read by the memory, for example: a ₁ , a ₂ , a ₃ , a ₄ , because the present invention is processed for the sub-pixel 303, the 5M panel with a resolution of 2560×2048 has 2560×3 positions on the first line of the sub-pixel 303, that is, the image uniformity can be increased by 3 times. At this time, the compensation value of the 10th monochrome sub-pixel 303 at the L position is determined: the coefficient a ₁ =0.997 of the first line, the coefficient a ₂ =-4.287×10^(-6), and the coefficient a ₃ =9.039× 10^(-9), coefficient a ₄ =-5.06×10^(-12), and the initial position x _o =0 of the sub-pixel 303 interpolation, and the position x _i =10 of the sub-pixel 303 to be interpolated, Input uniformity compensation formula S ( xi )= a ₁ ×( x _i - x _o ) ⁰ + a ₂ ×( x _i - x _o ) ¹ + a ₃ ×( x _i - x _o ) ² + a ₄ ×( x _i - x _o ) ³ , the compensation value is 0.99696616394, and then the digital image hierarchy of the 10th monochrome sub-pixel 303 at the L position is obtained, and the output value is equal to the 10th monochrome sub-pixel 303 at the L position. Digital image hierarchy input value multiplied by its relative For the compensation value, if the 10th monochrome sub-pixel 303 of the first line has an input value of 100 in the original digital image hierarchy of the L position, the digital image layer output value obtained by the operation is 99.696616394. It can be seen that the present invention has a corresponding coefficient for each line of the panel resolution, and is calculated by the uniformity compensation formula to obtain a compensation value, and then the compensation value and the corresponding sub-pixel 303. The digital image layer input value can be multiplied to obtain the digital image layer output value of the sub-pixel 303 of the present invention, which can effectively compensate for the image uniformity and improve the image uniformity to 95%.

4 is a schematic diagram of a system according to a second embodiment of the digital image processing system of the present invention. It can be seen that the system further includes a shaking device 60. After the data output device 50, the loading device 60 can be Sub-pixel 303 digital image layer output value for global uniform processing, to solve the boundary blurring effect, effectively improve the image softness, make the human eye visual effect better, more suitable for long-term use without hurting the eye, as for the remaining digital image processing system 1 The structure of the structure or the related function main operation is the same as that of the foregoing embodiment, and details are not described herein again.

Next, please refer to FIG. 5 and FIG. 2 and FIG. 4 , wherein FIG. 5 is a schematic flowchart of the first embodiment of the digital image processing method 2 of the present invention. The digital image processing method 2 is as follows:

Step 5001: Providing a coefficient operation device 10, which calculates a plurality of coefficients according to a plurality of point brightness values, and divides the screen into a plurality of intervals, which may be 4, 16, 36, ..., and continues with a brightness sensor (Light sensor) 101. Measuring the middle point brightness value of the interval, continuously estimating the overall brightness plane curve, and obtaining a plurality of coefficients of each line for subsequent calculation of the compensation value of each sub-pixel 303, and then proceeding to step 5002.

Step 5002: A coefficient temporary storage device 20 is provided for storing a plurality of coefficients for subsequent calculation of the compensation value of each sub-pixel 303, and then proceeds to step 5003.

Step 5003: An image input device 30 is provided for transmitting and inputting an image signal 301. The image signal 301 is composed of a plurality of pixels 302. Each of the pixels 302 includes a plurality of sub-pixels 303, wherein the sub-pixels 303 can be colored. The RGB of the image signal (where: R is red-red; G is green-green; B is blue-blue) or any sub-pixel 303 of the monochrome image signal (where: L is the representation) Left-left; C is a medium-center; and R is a right-right one of the sub-pixels 303, and each sub-pixel 303 has a digital image hierarchy, and then proceeds to step 5004.

Step 5004: After a arithmetic unit 40, the coefficient line from the temporary storage device 20 reads a plurality of coefficients, the coefficients with a plurality of uniformly compensation equation S (x _i) calculates, in order to calculate each sub-pixel 303 The compensation value finally proceeds to step 5005.

Step 5005: A data output device 50 is provided for multiplying the compensation value of each sub-pixel 303 by the digital image level of each sub-pixel 303 and outputting it to a screen.

The following is a schematic flowchart of the second embodiment of the digital image processing method 2 of the present invention. The method of the digital image processing method 2 or the related function main operation method are the same as the foregoing embodiment. For further description, the description step 6006 is further added. The method further provides a dithering device 60 for uniformly processing the entire image hierarchy, which can effectively improve the image softness and make the human eye look better and more suitable for a long time. Watch.

While the present invention has been described above in terms of the preferred embodiments thereof, it is not intended to limit the scope of the present invention, and may be made by those skilled in the art without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the patent application attached to the specification.

1‧‧‧Digital Image Processing System

2‧‧‧Digital image processing method

10‧‧‧ coefficient computing device

20‧‧‧ coefficient temporary storage device

30‧‧‧Image input device

40‧‧‧ arithmetic device

50‧‧‧ data output device

60‧‧‧Shake device

101‧‧‧Brightness measuring device

301‧‧‧Image signal

302‧‧ ‧ pixels

303‧‧‧Subpixel

5001, 5002, 5003, 5004, 5005‧ ‧ steps

6001, 6002, 6003, 6004, 6005, 6006‧‧‧ steps

1 is a schematic diagram of a system of a first embodiment of a digital image processing system of the present invention; FIG. 2 is a schematic diagram of image signals of the digital image processing system of the present invention; and FIG. 3 is a cubic nonlinear uniformity compensation of the present invention. formula S (x _i) computing a schematic flow chart; a schematic diagram of a second embodiment of the system according to the digital image processing system of the present invention lines in FIG. 4; the first embodiment of the process of digital image processing of the present invention Figure 5 is a schematic view of the method; FIG. 6 is a schematic flow chart of a second embodiment of the digital image processing method of the present invention.

1‧‧‧Digital Image Processing System

10‧‧‧ coefficient computing device

20‧‧‧ coefficient temporary storage device

30‧‧‧Image input device

40‧‧‧ arithmetic device

50‧‧‧ data output device

101‧‧‧Brightness measuring device

301‧‧‧Image signal

Claims (10)

A digital image processing system for compensating for uniformity of a liquid crystal screen, comprising: a coefficient operation device for calculating a plurality of coefficients according to a plurality of point brightness values; a coefficient temporary storage device for storing the plurality of coefficients; an image input The device is configured to transmit and input an image signal, wherein the image signal is composed of a plurality of pixels, each of the pixels includes a plurality of sub-pixels, and each of the sub-pixels has a digital image hierarchy; After reading the plurality of coefficients in the coefficient temporary storage device, calculating the plurality of coefficients and a uniformity compensation formula S ( x _i ) to calculate a compensation value of each of the sub-pixels; and a data output device, The multi-pixel compensation value is multiplied by the digital image level of each of the sub-pixels and output to a screen. The digital image processing system of claim 1, further comprising a dithering device for connecting to the data output device. The digital image processing system of claim 1, wherein the coefficient temporary storage device is a memory. The digital image processing system according to claim 1, wherein the uniformity compensation formula S ( x _i ) is: S ( x _i ) = a ₁ × ( x _i - x _o ) ⁰ + a ₂ × ( x _i - x _o ) ¹ + a ₃ ×( x _i - x _o ) ² + a ₄ ×( x _i - x _o ) ³ +...+ a _n ×( x _i - x _o ) ⁿ , where a ₁ , a ₂ , a ₃ , a ₄ ... a _n is an arbitrary real number, and x _o is a sub-pixel interpolation start position, and x _i is a sub-pixel position to be subjected to interpolation processing. The digital image processing system of claim 1, wherein the plurality of dot luminance values are measured by a luminance meter. The digital image processing system of claim 1, wherein the coefficient computing device is a PC or a barebone system. According to the digital image processing system of claim 1, wherein the sub-pixel can be any sub-pixel of R (red) G (green) B (blue) of the color image signal or a monochrome image signal. L (left) C (center) R (right) any of the sub-pixels. A digital image processing method for compensating for uniformity of a liquid crystal screen, comprising: providing a coefficient operation device for calculating a plurality of coefficients according to a plurality of point brightness values; providing a coefficient temporary storage device for storing the plurality of coefficients; providing An image input device for transmitting and inputting an image signal, wherein the image signal is composed of a plurality of pixels, each of the pixels includes a plurality of sub-pixels, and each of the sub-pixels has a digital image hierarchy; and an arithmetic device is provided After reading the plurality of coefficients from the coefficient temporary storage device, calculating the complex coefficients and a uniformity compensation formula S ( x _i ) to calculate a compensation value for each of the sub-pixels; A data output device is configured to multiply the compensation value of each of the sub-pixels and the digital image level of each of the sub-pixels to output to a screen. According to the digital image processing method of claim 8, the method further provides a dithering device for uniformly processing the entire digital image hierarchy. According to the digital image processing method of claim 8, wherein the sub-pixel can be any sub-pixel of R (red) G (green) B (blue) of the color image signal or L of the monochrome image signal. (left) Any sub-pixel in C(center)R(right).