CN110415264B - Motion detection circuit and method - Google Patents

Abstract

The invention provides a motion detection circuit and a motion detection method. The motion detection circuit comprises a detection unit for obtaining a current picture and judging whether a specific pixel exists in the current picture. The motion detection circuit further comprises a signature generator and a comparator. The signature generator is used for executing an updating program for each specific pixel. The update procedure includes: adding the coordinate information of the specific pixel to the corresponding signature value, and updating at least one bit in the corresponding signature value. The comparator is used for comparing the signature value of the current picture with the signature value of the previous picture to judge whether the current picture is an action picture or not.

Description

Motion detection circuit and method

Technical field

The invention relates to an action detection method and circuit for calculating a signature value to determine an action picture.

Background technique

In the field of image processing, in some situations it is necessary to determine whether there are action scenes in a video. In order to detect action scenes, you can calculate the difference between the front and rear images, calculate a histogram, etc. However, the complexity of these methods may be high. Therefore, how to propose a low-complexity algorithm to determine action scenes is an issue of concern to those skilled in the field.

Contents of the invention

An embodiment of the present invention proposes a motion detection circuit, including a detection unit to obtain the current picture and determine whether there are specific pixels in the current picture, where the specific pixels refer to pixels at the edge or have specific hue, saturation, brightness, texture of pixels. The motion detection circuit also includes a signature generator and a comparator. The signature generator is used to perform the update process for each specific pixel. This update procedure includes: adding the coordinate information of the specific pixel to the corresponding signature value, and updating at least one bit in the corresponding signature value. The comparator is used to compare the signature value of the current screen with the signature value of the previous screen to determine whether the current screen is an action screen; if the signature values of the current screen and the previous screen are different, it means that the current screen is an action screen.

In some embodiments, the current picture includes multiple blocks, and each block has a corresponding signature value. When initializing the signature value of the current screen and the signature value of the previous screen, the same default value is used for the signature values corresponding to blocks with the same position.

In some embodiments, in the update process, the signature generator is used to shift the corresponding signature value to the left or right by multiple bits, and add the X coordinate and Y coordinate of the specific pixel relative to the corresponding block to the corresponding signature value. among the signature values.

In some embodiments, in the update procedure, the steps for the signature generator to update the median of the corresponding signature value include: obtaining S digits from the signature value, where S is a positive integer greater than 1; Perform a logical operation; and update at least one bit in the signature value to the result of the logical operation.

In some embodiments, the number of updated bits of the signature value in the update procedure is greater than 1, and the signature generator obtains different S bits when updating different bits in the signature value.

From another perspective, embodiments of the present invention propose a motion detection method, which is suitable for motion detection circuits. The motion detection method includes: obtaining the current picture and determining whether there are specific pixels in the current picture, where the specific pixel refers to Pixels at edges or pixels with specific hue, saturation, brightness, or texture: perform an update procedure for each specific pixel. This update procedure includes: adding coordinate information of a specific pixel to the corresponding signature value; and updating at least one bit in the corresponding signature value. The above-mentioned action detection method also includes: comparing the signature value of the current screen with the signature value of the previous screen to determine whether the current screen is an action screen; if the signature values of the current screen and the previous screen are different, it means that the current screen is an action screen picture.

In some embodiments, the current picture includes multiple blocks, and each block has a corresponding signature value. The action detection method also includes: when initializing the signature value of the current screen and the signature value of the previous screen, the same default value is used for the signature values corresponding to blocks with the same position.

In some embodiments, the action detection method further includes: in the update procedure, shifting the corresponding signature value to the left or right by multiple bits, and adding the X coordinate and Y coordinate of the specific pixel relative to the block to which it belongs. among the corresponding signature values.

In some embodiments, the step of updating the median of the signature value in the update procedure includes: obtaining S bits from the signature value, where S is a positive integer greater than 1; performing logical operations on the S bits; and converting the signature value to The bits in the chapter value are updated with the result of the logical operation.

In some embodiments, the number of updated bits is greater than 1 during the update procedure. The action detection method also includes: when updating different bits in the signature value, different S bits are obtained.

In order to make the above-mentioned features and advantages of the present invention more obvious and understandable, embodiments are given below and described in detail with reference to the accompanying drawings.

Description of the drawings

FIG. 1A is a schematic diagram of a display device according to an embodiment;

1B is a block diagram illustrating a motion detection circuit according to an embodiment;

Figure 2 is a schematic diagram illustrating calculation of a signature value according to an embodiment;

Figure 3 is a schematic diagram illustrating adding coordinate information to a signature value according to an embodiment;

Figure 4 is a schematic diagram illustrating updating the median signature value according to an embodiment;

Figure 5 is a schematic diagram illustrating comparison of signature values in two images according to an embodiment; and

FIG. 6 is a flowchart illustrating a motion detection method according to an embodiment.

Detailed ways

FIG. 1A is a schematic diagram illustrating a display device according to an embodiment. In the embodiment of FIG. 1A , the display device 100 includes a timing controller 110 , a source driver 120 , a gate driver 130 and a display panel 140 . The timing controller 110 includes a motion detection circuit 111 to perform the motion detection method described below. However, the motion detection circuit 111 and method can also be applied to other electronic devices, such as smart phones, tablet computers, personal computers, notebook computers, industrial computers, display screens, touch screens, etc.

FIG. 1B is a block diagram illustrating a motion detection circuit according to an embodiment. Referring to FIG. 1B , the action detection circuit 111 includes a detection unit 150 , a signature generator 160 , a comparator 170 and a register 180 . The signature generator 160 includes a register 161 and a computing unit 162. The operation of the motion detection circuit 111 will be described below with reference to FIG. 1B and FIG. 2 .

FIG. 2 is a schematic diagram illustrating calculation of a signature value according to an embodiment. Referring to FIG. 2 , the detection unit 150 obtains the current frame 200 and determines whether there are specific pixels in the current frame. In this embodiment, the detection unit 150 can use any edge detection algorithm, and the above-mentioned specific pixels refer to pixels at the edge. This edge detection algorithm uses a filter, for example, and performs a convolution operation on the current picture 200 based on the filter. The filter result can be compared with a critical value. If it is greater than the critical value, it is determined to be a specific pixel. The above-mentioned filter can be any suitable high-pass filter, such as a Sobel filter, etc., and the present invention is not limited thereto. Those with ordinary knowledge in the art can adopt any edge detection algorithm, such as a canny edge detector, etc. The present invention does not limit the content of the edge detection algorithm. In other embodiments, the detection unit 150 may also determine whether each pixel in the current picture 200 has a specific brightness, hue, or saturation, or determine whether the current picture 200 has a specific texture (such as lines, planes, arbitrary geometric shape, etc.) to obtain specific pixels. In other words, the above-mentioned specific pixels may also be pixels with specific hue, saturation, brightness, and texture, and the present invention is not limited thereto. In FIG. 2 , only specific pixels P1 and P2 are shown as examples to illustrate the subsequent algorithm.

In some embodiments, the current picture 200 may be divided into M x N blocks, where M and N are positive integers. In some embodiments, the positive integers M and N are 16, but in other embodiments they can also be 8, 32, 64 or other numerical values, and the invention is not limited thereto. In some embodiments, the width of the current screen 200 may not be divisible by a positive integer M, so the width of the first M-1 blocks can be set to be the same, and the width of the M-th block may be larger or smaller. In some embodiments, the width and height of each block can be arbitrarily designed or different from each other. The shape of the blocks can also be other polygons or circles, and is not limited to rectangles.

A signature value (signature) can be set for each block. These signature values are stored in the register 161. The above-mentioned specific pixels are used to update the signature value. If the signature in the same block If the value changes, it means that the brightness, color, edge, or texture in the picture has changed, which means that an action has occurred. The following will explain how to calculate the signature value. First, the computing unit 162 will initialize the signature value. In some embodiments, the signature value of each block in the current screen 200 can be initialized to different values, and can be randomly generated. In other embodiments, the signature values of several blocks in the current screen 200 can also be initialized to the same value, and the present invention is not limited thereto.

For each specific pixel, the signature generator 160 performs an update procedure. Here, specific pixels P1 and P2 are taken as an example. The specific pixels P1 and P2 belong to the block 210 . When executing the update procedure on specific pixels P1 and P2, the signature generator 160 will update the signature value corresponding to the corresponding block 210. In other words, for the signature value corresponding to block 210, the above update procedure will be executed twice. Specifically, the update procedure includes at least two steps: first, adding the coordinate information of the specific pixel relative to the block it belongs to to the signature value corresponding to the block it belongs to; second, updating at least one of the signature values. Bit.

In the above first step, the coordinate information of the specific pixel relative to the block includes, for example, X coordinate and Y coordinate. These two coordinates take the upper left corner of the block as the origin. For example, taking coordinate O as the origin, the coordinate information of the specific pixel P1 is expressed as (3,4), and the coordinate information of the specific pixel P2 is expressed as (6,8), for example. In some embodiments, the values of the X coordinate and the Y coordinate do not exceed 255, so the X coordinate and the Y coordinate can be represented by 8 bits each. For general expression, these two coordinates are represented as x _local below. with y _local . Figure 3 is a schematic diagram of adding coordinate information to the signature value. Please refer to Figure 3. One embodiment of the above "adding coordinate information to the signature value" is to first shift the signature value to the left or right by a plurality of times. bit, in the example of Figure 3, it is shifted to the right by 16 bits. Next, the coordinate x _local and the coordinate y _local are added to the signature value. This operation can be expressed as the following program (1).

LFSR _i =(y _local ＜＜8+x _local )＜＜16+LFSR _i ＞＞16…(1)

Among them, LFSR _i represents the signature value corresponding to the i-th block, << represents a left shift, >> represents a right shift, and + represents an OR logical operation. In the above embodiment, the coordinates are added to the most significant bit (MSB), but in some embodiments, the signature value can also be shifted to the left by multiple bits, and then the coordinates x _local and y _local can be Added to the least significant bit (LSB). Or, when the width and height of the block are larger or smaller, the number of bits required for the coordinates x _local and y _local may be more or less, and correspondingly the signature value may be shifted by fewer or more bits. In some embodiments, it is also possible to directly replace part of the signature value with coordinates x _local and y _local without shifting the signature value. The present invention does not limit the positions of coordinates x _local and y _local in the new signature value. For example, the coordinates x _local and y _local can also be dispersedly stored in the new signature value. In some embodiments, the above-mentioned step of "adding coordinate information to the signature value" can also be to perform arbitrary logical operations on the signature value and the coordinates x _local and y _local , such as addition, subtraction, multiplication, division, logical AND, logical OR, etc. For calculation, it is enough to change the bits in the signature value according to the coordinates x _local and y _local , and the present invention is not limited to this.

Next, the second step of the above update procedure is described: updating at least one bit in the signature value. Please refer to Figure 4. In some embodiments, S digits can be obtained from the signature value, where S is a positive integer, such as 12, 13, 14 or other values. Next, logical operations are performed on these S bits, and one bit in the signature value is updated as the result of the logical operation. This step can be performed U times to update U bits in the signature value, where U is Positive integer, such as 8, 9, 10 or other numerical values. In the following embodiments, the above-mentioned logical operation is an exclusive OR operation (XOR operation), but in other embodiments, it can also be changed to an AND or OR operation, and the present invention is not limited thereto. In some embodiments, when U is greater than 1, different S bits are obtained to update different bits each time a bit is updated. For example, Figure 4 shows two updates. The upper part of Figure 4 obtains 13 bits such as bits b ₃₀ , b ₂₈ ...b ₁ to perform a mutually exclusive OR operation, and updates bit b ₃₁ to a mutually exclusive OR operation. The result of exclusive OR operation. The lower part of Figure 4 obtains 13 bits such as bits b ₃₁ , b ₂₉ ...b ₀ and performs a mutually exclusive OR operation, and updates bit b ₁₆ to the result of the mutually exclusive OR operation. From another perspective, this step can be expressed as the following procedure (2).

here, is a mutually exclusive OR operation, b _s,1 ...b _s,S represents the selected bit, for example, in the upper half of Figure 4, b _{s, 1} ...b _s,S is equal to b ₃₀ , b ₂₈ ... b ₁ , b _s,1 ...b _s,S in the lower half of Figure 4 are equal to b ₃₁ , b ₂₉ ...b ₀ . b _u represents the bit to be updated. Equation (2) can be executed U times, and the selected bit b _s can be different in each execution. For example, in the upper part of Figure 4, b _u is equal to b ₃₁ , and in the lower part of Figure 4 In the half, b _u is equal to b ₁₆ . Please refer to Figure 3 and Figure 4. In some embodiments, since the signature value LFSR _i will be shifted to the right by 16 bits, in the above equation (2), the bit b _u will only be the bit b ₃₁ ~ b ₁₆ one of them. In some embodiments, each update in Figure 4 is a parallel operation, that is, the selected bits are bits in the old signature value, not the new signature value. For example, the selected bit b ₃₁ in the lower half of FIG. 4 is the bit before the update in the upper half of FIG. 4 is performed. However, in some embodiments, each update in Figure 4 can also be executed sequentially, that is, the bit b ₃₁ selected in the lower half of Figure 4 is the bit after the update in the upper half of Figure 4 is completed. The present invention does not This limit.

Please refer to FIG. 1B . After the above-mentioned update process is executed for each specific pixel in the current frame 200 , a plurality of signature values 181 of the current frame 200 will be transmitted to the register 180 and the comparator 170 . In addition, the register 180 stores the signature value of the previous picture, and the signature value 182 of the previous picture is also sent to the comparator 170 . The comparator 170 will determine whether the signature value 181 of the current screen is the same as the signature value 182 of the previous screen. If the two are not the same, it means that the current screen is an action screen. It is worth noting that since each block has a corresponding signature value, the comparator 170 can compare two signature values corresponding to the same block to determine whether an action has occurred in this block. For example, please refer to Figure 5. On the timeline, the previous picture 500 is located before the current picture 200. The previous picture has a block 510, where the relative position of the block 510 in the picture 500 is the same as that of the block 210 in the picture 200. relative position in. It is worth mentioning that when initializing the signature value in the current screen 200 and the signature value in the previous screen 500, the same default value is used for the two signature values corresponding to the blocks in the same position. In addition, when executing the above equations (1) and (2) on block 210 and block 510, all variables are exactly the same, such as shifting by the same number of bits, using the same positive integers U and S, and using the same Bits b _u , b _{s, 1} ...b _{s, S,} etc., so that the two signature values corresponding to block 210 and block 510 can be compared with each other.

If the signature value corresponding to block 210 is not the same as the signature value corresponding to block 510, it means that an action occurred in blocks 210 and 510. After obtaining this judgment result, additional procedures can be executed, such as The timing controller 110 may perform over drive processing. However, the present invention does not limit which operations or procedures are subsequently performed.

Figure 6 is a flowchart illustrating a motion detection method according to an embodiment. Please refer to Figure 6. In step 601, the current frame is obtained and whether there is a specific pixel in the current frame is determined. In step 602, it is determined whether there are still specific pixels in the current picture. If the result of step 602 is yes, in step 603, the coordinate information of the specific pixel is added to the corresponding signature value. In step 604, at least one bit in the corresponding signature value is updated. Steps 603 and 604 are also called update procedures. Steps 602 to 604 will be executed repeatedly until all specific pixels have been processed. If the result of step 602 is no, the signature value of the current picture will be compared with the signature value of the previous picture to determine whether the current picture is an action picture ( Step 605). However, each step in Figure 6 has been described in detail above and will not be described again here. It is worth noting that each step in Figure 6 can be implemented as multiple program codes or circuits, and the present invention is not limited thereto. In addition, the method in Figure 6 can be used in conjunction with the above embodiments or alone. In other words, other steps can also be added between the steps in Figure 6 .

Although the present invention has been disclosed above through embodiments, they are not intended to limit the present invention. Any person skilled in the art can make some modifications and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention is The scope of protection shall be determined by the appended claims.

Symbol Description

100: Display device

110: Timing controller

111: Action detection circuit

120: Source driver

130: Gate driver

140: Display panel

150: Detection unit

160: Signature generator

161, 180: buffer

162: Operation unit

170: Comparator

181, 182: Signature value

200: Current screen

210: Block

M, N: positive integers

P1, P2: pixels

O: coordinates

b ₀ ~ b ₃₁ : bit

x _local , y _local : coordinates

500: Front screen

510: Block

601～605: Steps

Claims (10)

1. An action detection circuit, characterized in that it includes a detection unit to obtain the current picture and determine whether there are specific pixels in the current picture, wherein the specific pixels refer to pixels at the edge or have a specific hue, Saturation, brightness, texture of pixels, the motion detection circuit includes: A signature generator is used to perform an update procedure for each specific pixel, and the update procedure includes: Add the coordinate information of the specific pixel to the corresponding signature value; and Update at least one of the corresponding signature values; and A comparator used to compare the signature value of the current picture with the signature value of the previous picture to determine whether the current picture is an action picture; if the signature values of the current picture and the previous picture are not the same , it means that the current picture is an action picture. 2. The motion detection circuit of claim 1, wherein the current picture includes a plurality of blocks, and each block in the plurality of blocks has a corresponding signature value. When initializing the signature value of the current picture and the signature value of the previous picture, the same default value is used for the signature value corresponding to the block with the same position. 3. The action detection circuit of claim 2, wherein in the update procedure, the signature generator is used to shift the corresponding signature value to the left or right by a plurality of bits, And the X coordinate and Y coordinate of the specific pixel relative to the block it belongs to are added to the corresponding signature value. 4. The action detection circuit according to claim 3, wherein in the update procedure, the step of the signature generator updating the at least one digit in the corresponding signature value includes: Obtain S digits from the signature value, where S is a positive integer greater than 1; Perform logical operations on the S bits; and The at least one bit in the signature value is updated to the result of the logical operation. 5. The action detection circuit of claim 4, wherein in the update procedure, the number of updated at least one bit in the signature value is greater than 1, and the signature is generated When updating different bits in the signature value, the device obtains different S bits. 6. An action detection method, characterized in that it is suitable for action detection circuits, and the action detection method includes: Obtain the current picture and determine whether there are specific pixels in the current picture, where the specific pixels refer to pixels at the edge or pixels with specific hue, saturation, brightness, or texture; An update procedure is performed on each specific pixel, and the update procedure includes: Add the coordinate information of the specific pixel to the corresponding signature value; and Update at least one of the corresponding signature values; and Comparing the signature value of the current picture with the signature value of the previous picture to determine whether the current picture is an action picture; if the signature values of the current picture and the previous picture are different, it means that the signature value of the current picture is different from that of the previous picture. The current screen is an action screen. 7. The action detection method of claim 6, wherein the current picture includes a plurality of blocks, and each block in the plurality of blocks has a corresponding signature value, so The above action detection methods also include: When initializing the signature value of the current picture and the signature value of the previous picture, the same default value is used for the signature value corresponding to the block with the same position. 8. The action detection method according to claim 7, further comprising: In the update procedure, the corresponding signature value is shifted by a plurality of bits to the left or right, and the X coordinate and Y coordinate of the specific pixel relative to the block to which it belongs is added to the corresponding signature. among the values. 9. The action detection method according to claim 8, wherein the step of updating the at least one bit in the corresponding signature value in the update procedure includes: Obtain S digits from the signature value, where S is a positive integer greater than 1; Perform logical operations on the S bits; and The at least one bit in the signature value is updated to the result of the logical operation. 10. The action detection method according to claim 9, wherein in the update procedure, the number of the at least one bit that is updated is greater than 1, and the action detection method further includes: When updating different bits in the signature value, different S bits are obtained.