CN1971681B - Method for reducing sparkling sub-field alignment when eliminating dynamic false contour - Google Patents

Abstract

The present invention is a subfield arrangement method for reducing flicker when eliminating dynamic false contours. On the basis of adopting the reverse order of the subfield weights of adjacent odd and even frames, the subfields of odd or even frames A subfield with a relatively low weight is set at the end with the highest weight, and the subfield with a relatively low weight is placed at the other end opposite to the subfield with a weight of 1 for this frame. The present invention provides a reasonable transition between subfields at the corresponding ends of the upper and lower frames through the setting of subfields with relatively low weights, which effectively reduces the serious flickering on some grayscale displays caused by it. Phenomenon.

Description

A Subfield Arrangement Method for Reducing Flicker in Elimination of Dynamic False Contour

technical field

The present invention relates to a method for realizing image multi-level grayscale display on a flat panel display by using a sub-field display method to improve display quality, in particular to a method for reducing the generation of some grayscale display caused by eliminating dynamic false contours Subfield arrangement method for severe flicker phenomenon.

Background technique

Some flat-panel displays, such as plasma displays (PDP), etc., usually divide a frame of image into multiple sub-fields to display in order to realize the multi-gray level display of images, and different sub-fields have brightness with different weights. Field combination can realize multi-level grayscale display of images.

For example, in order to achieve 256-level grayscale, an AC plasma display usually divides a frame of image into 8 subfields (subfield: English is subfield, abbreviated as SF. SF1 represents the first subfield, and so on), the brightness of the subfield The weight relationship is: SF1:SF2:SF3:SF4:SF5:SF6:SF7:SF8=1:2:4:8:16:32:64:128. 256 gray levels between 0 and 255 can be obtained through different combinations of these 8 subfields. For example: when displaying gray level 0, all SF1~SF8 will not emit light; when displaying gray level 127, all SF1~SF7 will emit light, and SF8 will not emit light; when displaying gray level 128, all SF1~SF7 will not emit light, and SF8 will emit light; When the gray level is 255, all the SF1-SF8 subfields emit light.

However, when the above-mentioned subfield method is used to display multi-level grayscale images, the phenomenon of dynamic false contour (Dynamic False Contour) will appear, that is, when displaying black and white moving images, grayscale disorder will occur; when displaying color moving images, Color disturbances may also occur. The generation of dynamic pseudo-contour is the combined effect of the visual physiological characteristics of the human eye and the sub-field display method.

This phenomenon can be explained by the still image displayed in the subfield mode shown in Figure 1. When the still image moves to the right, if the order of the subfields is SF1: SF2: SF3: SF4: SF5: SF6: SF7: When SF8=1:2:4:8:16:32:64:128, the human eye will observe an obvious bright line between grayscale 127 and grayscale 128, and its grayscale corresponds to 127+ 128=255; and if the order of subfields is SF1:SF2:SF3:SF4:SF5:SF6:SF7:SF8=128:64:32:16:8:4:2:1, human eyes will observe There is an obvious dark line between the gray level 127 and the gray level 128, and the gray level corresponds to 0+0=0, as shown in FIG. 2 . In order to eliminate the phenomenon of dynamic false contours generated when displaying images with multi-level gray levels, the patent application titled "A Method for Reducing Dynamic False Contours in AC Plasma Display Panels" with application number 200410073011. Adjacent frames take the opposite order of sub-field weights, so that the generated dynamic pseudo-contour effects are averaged with each other. In this example, (255+0)/2=127.5 can be obtained, so that the human eye can feel the difference between grayscale 127 and grayscale The gray level 127.5 with a natural transition is presented between the levels 128, thereby eliminating the dynamic false contour phenomenon generated when the image is displayed with multiple gray levels.

Although the compensation method of the opposite order of subfield weights in adjacent frames can reduce dynamic false contours, the design of the order of the subfields causes some gray levels to be displayed at intervals that are too large, resulting in the display of some gray levels For example, the display interval of gray level 1 is as long as 2 times the frame period, which is far lower than the critical frequency of 50Hz that the human eye can detect flicker. Therefore, it is necessary to provide an improved method for reducing the serious flicker phenomenon on some gray scale displays caused by the dynamic false contour by adopting the compensation method of the opposite order of the subfield weights of adjacent frames.

Contents of the invention

Therefore, the object of the present invention is to provide a method for arranging subfields that reduces flicker when eliminating dynamic false contours. This method adopts a compensation method in reverse order for eliminating adjacent frame subfield weights, so as to reduce the effects of dynamic false contours. Effect of severe flickering on some grayscale displays.

The object of the present invention is to provide a subfield arrangement method that reduces flicker when eliminating dynamic false contours. In this method, a subfield with a relatively low weight is set at the end of the subfield with the highest weight in odd frames or even frames to balance the gray areas. Degrees are spaced between displayed times to prevent flickering.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A subfield arrangement method for reducing flicker when eliminating dynamic false contours. On the basis of arranging the subfield weights of adjacent odd and even frames in reverse order, set them at the end of the odd frame or even frame with the highest subfield weight. A subfield with a relatively low weight, and place the subfield with a relatively low weight at the opposite end from the subfield with a weight of 1 for the frame.

In the subfield arrangement method for reducing flickering when eliminating dynamic false contours, the relatively low subfield is to increase or split the subfield with the highest weight at the end of the subfield of each frame. Separate a subfield with relatively low weight.

The described subfield arrangement method that reduces flickering when eliminating dynamic false contours, when adding a relatively low subfield, the weight of the subfield is less than 8; when splitting the subfield, the original subfield with the highest weight For splitting, the subfield with the highest weight is a subfield with a weight of N (N>1), and split it into two subfields with a weight of 1 and a weight of N−1.

More specifically, the best way is to set the weights of the added or split subfields with relatively low weights to 1.

The described subfield arrangement method for reducing flicker when eliminating dynamic false contours is specifically implemented as follows: a subfield with a weight of 1 is set at the front end and end of the subfield of the odd frame or the even frame, wherein the front end and the end The subfields of are generated by adding or splitting the subfield with the highest weight.

In the above-mentioned subfield arrangement method that reduces flickering when eliminating dynamic false contours, the weight of the added or split subfields with lower weights is set to 1, so as to achieve any grayscale in any two adjacent frames. The light-emitting time interval of the sub-field discharge is not greater than one frame period, so as to realize flicker-free display.

Compared with the prior art, the present invention eliminates false contours on the basis of arranging the subfields in reverse order for the weights of any adjacent odd and even two frames, and by setting the subfields with relatively low weights, it is There is a reasonable transition between the subfields at the corresponding ends of the upper and lower frames, which effectively reduces the serious flicker phenomenon on some gray scale displays caused by it.

Description of drawings

Fig. 1 is a schematic diagram of the observation effect of the human eye on a still image as an example,

Figure 2 is a schematic diagram of the generation mechanism of dynamic false contours and the reduction of dynamic false contours by adjacent frame compensation method,

Fig. 3 is a schematic diagram of the subfield arrangement of the basic adjacent frame compensation method,

Fig. 4 is a schematic diagram of subfield arrangement of the improved adjacent frame compensation method of the present invention,

Fig. 5 is a schematic diagram of the gray scale representation method of the improved adjacent frame compensation method of the present invention,

Fig. 6 is a schematic diagram of subfield arrangement of another improved adjacent frame compensation method of the present invention,

Fig. 7 is a schematic diagram of subfield arrangement of another improved adjacent frame compensation method of the present invention.

Detailed ways

The implementation of the present invention will be described in detail below in conjunction with the accompanying drawings. The implementation is illustrated by using the 256-level grayscale display as an example.

First, arrange the subfields in the way of adjacent frame compensation. For example, when displaying 256-level gray scale, the subfield order of the first frame is SF1:SF2:SF3:SF4:SF5:SF6:SF7:SF8=1:2:4:8 : 16: 32: 64: 128; the order of subfields in the second frame is just the opposite, that is, SF1: SF2: SF3: SF4: SF5: SF6: SF7: SF8: SF = 128: 64: 32: 16: 8: 4: 2 : 1, as shown in Figure 3.

An additional subfield is then added with a luminance weight of 1 and positioned at the opposite end of the sequence of subfields from the original subfield with a weight of 1. It is also possible to split an original subfield with a weight of N (N>1) into two subfields with a weight of 1 and a weight of N-1, and divide the newly generated subfield with a weight of 1 into Placed at the other end of the subfield sequence opposite to the original subfield with a weight of 1.

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in FIG. 4 , in this example, the subfield with a weight of 128 is split into two subfields with a weight of 127 and a weight of 1 based on the subfield method in FIG. 3 . Among the two new subfields, the subfield with a weight of 127 is still located at the position of the original subfield with a weight of 128, and the subfield with a weight of 1 is arranged adjacent to it. This constitutes a new arrangement of 9 subfields. When the present invention displays the first frame, the subfield arrangement is set as: SF1: SF2: SF3: SF4: SF5: SF6: SF7: SF8: SF9=1:2:4:8:16:32:64: 127:1, when displaying the second frame, the subfield arrangement is adjusted as: SF1:SF2:SF3:SF4:SF5:SF6:SF7:SF8:SF9=1:127:64:32:16:8:4: 2:1, and then the two frames alternate to achieve 256-level grayscale (image) display.

As shown in Figure 5, the purpose of preventing flickering can be achieved by skillfully selecting the sub-field representation method of the gray level. Taking the display of gray level 1 as an example, the first subfield with a weight of 1 is selected to emit light in both odd and even frames, so the interval between two light emission is 1 frame period, which satisfies the visual persistence characteristics of the human eye , no flicker is felt.

This subfield method is to add a new subfield with a weight of 1, so that in the case of adjacent frame compensation, when the order of subfields alternates positive and negative, it can ensure that there is a subfield with a weight of 1 as the first subfield, and then in The expression method of each gray level (except gray level 0) occupies the first subfield, thereby ensuring the maximum light-emitting interval for preventing flickering.

As shown in Figure 6, in this example, a subfield with a weight of 1 is added before the subfield with a weight of 128 in even frames. The subfield with a weight of 128 is still located The field is arranged adjacent to it, which is the first subfield. This constitutes a new arrangement of 9 subfields. Similarly, after the subfield with a weight of 128 at the end of the odd frame below, a subfield with a weight of 1 is also added, and the subfields of the even frame and the odd frame correspond one-to-one. When the first frame is an even frame, the subfield of the subfield The arrangement mode is set as: SF1: SF2: SF3: SF4: SF5: SF6: SF7: SF8: SF9 = 1: 128: 64: 32: 16: 8: 4: 2: 1, the second frame is an odd frame, and the The arrangement of subfields is: SF1: SF2: SF3: SF4: SF5: SF6: SF7: SF8: SF9 = 1: 2: 4: 8: 16: 32: 64: 128: 1, and then there are two frames like this Alternately, the display of 256-level grayscale (image) is realized.

Figure 7 shows the case of adding a subfield with a weight greater than 1 when odd frames and even frames are arranged alternately, where the weight of the added subfield is 2. Add a subfield with a weight of 2. The subfield with a weight of 128 is still located at the position of the original subfield with a weight of 128, and the subfield with a weight of 2 is arranged adjacent to it, that is, at the end of the odd frame, which constitutes a new 9 The arrangement of subfields; the first subfield of the even frame below the odd frame was originally a subfield with a weight of 128. At this time, a subfield with a weight of 2 is added to the front of the subfield to form a 9. The arrangement of the subfields. When the present invention displays the first frame, the subfield arrangement is set as: SF1: SF2: SF3: SF4: SF5: SF6: SF7: SF8: SF9=1:2:4:8:16:32:64: 128:2, when displaying the second frame, the subfield arrangement is adjusted as: SF1:SF2:SF3:SF4:SF5:SF6:SF7:SF8:SF9=2:128:64:32:16:8:4: 2:1, and then the two frames alternate to achieve 256-level grayscale (image) display.

Since the subfields with weight 2 in even frames and the subfields with weight 1 in odd frames, the difference in the weights of the subfields is very small, and there is no visual difference, and the visual effect is the same as that of the subfields with weight 1. The phenomenon of flickering can be eliminated.

In the above embodiments, it is worth noting that, no matter it is an even frame or an odd frame, the first subfield of each frame is preferably a subfield with a weight of 1, that is, when adding or splitting a subfield, first It is important to focus on the first subfield of each frame, which should be set as a subfield with a weight of 1. It is not very important to set the subfield at the end of each frame as a subfield with a weight of 1.

In addition, in practical applications and better implementations, whether it is adding subfields or splitting subfields, the subfields of the upper and lower frames need to be in one-to-one correspondence, that is, one subfield is added to the previous frame, and its kern A subfield is also added to the next frame of .

The above content is some specific descriptions of the embodiments of the present invention, and does not mean that all the embodiments of the present invention have been listed. Any technical content, purpose of the invention, and technical effects that are the same or similar to those of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (5)

1. A subfield arrangement method that reduces flickering when eliminating dynamic false contours, is characterized in that on the basis of taking the opposite order to the adjacent odd and even two frame subfield weights, in the subfields of odd frames or even frames A subfield with a relatively low weight is set at the end with the highest weight, and the subfield with a relatively low weight is placed at the other end opposite to the subfield with a weight of 1 for this frame. 2. The method for arranging subfields that produce flicker when reducing dynamic false contours as claimed in claim 1 is characterized in that the subfields with relatively low weights are increased at the highest end of the weighted subfields of each frame or the The subfield with the highest weight splits off a subfield with a relatively lower weight. 3. The method for arranging the subfields that produces flicker when reducing dynamic false contours as claimed in claim 1 or 2, when it increases the relatively low subfield of weight, the weight of the subfield is less than 8; when splitting the subfield, It is to split the original subfield with the highest weight. The subfield with the highest weight has a weight of N, where N>1, and split it into two subfields with a weight of 1 and a weight of N−1. 4 . The method for arranging subfields to reduce flicker when eliminating dynamic false contours as claimed in claim 3 , wherein the weight of the added subfields is 1. 5 . 5. The subfield arrangement method for reducing flickering as claimed in claim 1, wherein setting a relatively low weight subfield refers to setting a weight of 1 at the front end and end of any frame , wherein the front and end subfields are generated by adding or splitting the subfield with the highest weight.

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