CN100498825C - Method for determining sensing array of hand-held image motion tracking sensor - Google Patents

Abstract

A method for determining a sensor array of a handheld image motion tracking sensor, the sensor array being a rectangular sensor array, the method comprising: determining a first edge length; setting a reference block and the width of each pixel; calculating left and right maximum tracking speeds and front and rear maximum tracking speeds; the left and right maximum tracking speed meets the maximum left and right swinging speed of the human hand, and when the human hand has the same sense of strength, the front and back movement speed and the left and right movement speed maintain a specific value; and calculating the second side length according to the first side length through the steps. The invention utilizes the rectangular sensing array to reasonably reduce the sensing range of the sensing array corresponding to the forward and backward movement, so that the sensor can save the area of the sensing array and reduce the production and manufacturing cost, and the characteristics of reducing the data comparison amount and shortening the processing time are achieved when in use. The invention can be used for optical mouse and hand-held scanner.

Description

Method for Determining the Sensing Array of a Handheld Video Motion Tracking Sensor

Technical field:

The invention relates to a method for determining the sensing array of a hand-held image motion tracking sensor.

Background technique:

Today's hand-held image motion tracking sensors, such as optical mice, have a sensor composed of a square sensor array inside, and capture the images of the detected objects quickly and periodically at the current frequency, and then compare them The position change of the same feature in two consecutive images is used to convert the displacement data of this object.

Please refer to Fig. 3, it is a square induction array, the side length 31 of the square induction array is 10 pixels, first capture two time point continuous images, take a reference block 32 in the center of the first time point image, the reference area The block side length 33 is 4 pixels. According to the block comparison algorithm and the whole area search method, a sample block 34 with the size of the reference block 32 is taken from the image at the second time point. The sample block 34 is from left to right, up and down. For comparison, 49 sample blocks 34 can be compared, and a block most similar to the reference block 32 can be obtained after comparison.

Although the above-mentioned prior art can convert the displacement data of the object, the amount of data comparison is large, the processing time is long, and the area of the sensing array is wasted. Therefore, it generally cannot meet the needs of users in actual use.

Invention content:

The technical problem to be solved by the present invention is to provide a method for determining the sensing array of a hand-held image motion tracking sensor, which can save the area of the sensing array and reduce data comparison during use. volume and shorten processing time.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for determining the sensing array of the hand-held image motion tracking sensor, the sensing array is a rectangular sensing array, and the method for determining the sensing array at least includes the following steps:

(1) determine that the length of the first side of the sensing array is N, and assume that the length of the second side of the sensing array is M;

(2) Set a square reference block whose side length is K and the width W of each pixel;

(3) Estimate the left and right maximum tracking speed V _{x_max} and the front and rear maximum tracking speed V _{y_max} , the left and right maximum tracking speed is V _{x_max} = (NK)/2×f×W, the front and rear maximum tracking speed V _{y_max} =(MK)/2 ×f×W, where f is the current frequency;

(4) When having the same sense of strength, the forward and backward moving speed maintains a ratio q to the left and right moving speed, so V _{y_max} =q×V _{x_max} , namely (MK)/2×f×W=q×(NK)/ 2×f×W, and the left and right maximum tracking speed meets the maximum left and right swing speed of the hand;

(5) Using the above formula, calculate the length M of the second side, and thus determine the induction array.

The ratio is between 0 and 1.

Compared with the prior art, the present invention has the advantages that: the present invention utilizes a rectangular sensing array to reasonably reduce the sensing range corresponding to the forward and backward movement of the sensing array, which not only enables the sensor to save the area of the sensing array during use, thereby reducing production Manufacturing costs can be reduced, and the amount of data comparison and processing time can be shortened. The invention can be used in optical mouse and handheld scanner.

Description of drawings:

Fig. 1 is a schematic diagram of an induction array of the present invention.

Fig. 2 is a schematic diagram of an embodiment of the present invention.

Fig. 3 is a schematic diagram of an existing square sensing array.

Label description:

The length of the first side is 11 The length of the second side is 12

Reference block 13 Reference block side length 14

Width per pixel 15 sample blocks 16

Square sensing array side length 31 Reference block 32

Base block side length 33 Sample block 34

Detailed ways:

Please refer to FIG. 1 , which is a schematic diagram of the structure of the sensing array of the present invention. As shown in the figure: the sensing array of the handheld image motion tracking sensor of the present invention, the sensing array includes a first side length (N) 11 and a second side length (M) 12, and the second side length 12 is smaller than the The length of the first side is 11 to form a rectangular sensing array. The calculation process of the second side length 12 includes the following steps:

a, setting a reference block 13 and the width (w) 15 of each pixel, the reference block 13 is square and has a reference block side length (K) 14;

b. Calculate a left and right maximum tracking speed (V _{x_max} ) and a front and rear maximum tracking speed (V _{y_max} ), the left and right maximum tracking speed is (NK)/2×f×w, where f is the current frequency, then the front and rear maximum tracking speed The speed is (MK)/2×f×w;

c. The left and right maximum tracking speed can meet the maximum left and right swing speed of the hand, and with the same sense of strength, the front and rear moving speed maintains a ratio (q) to the left and right moving speed, and the ratio is between 0 and 1. So V _{y_max} =q×V _{x_max} , ie (MK)/2×f×w=q×(NK)/2×f×w;

d. After the above step c, calculate the second side length 12, and the second side length 12 is Nq+K(1-q).

Please refer to FIG. 2 , which is a schematic diagram of an embodiment of the present invention. As shown in the figure: the first side length (N) 11 of the rectangular sensing array is 10 pixels, and the side length (K) 14 of the reference block is 4 pixels, and the ratio (q) of the forward and backward movement speed to the left and right movement It is 0.7, and the ratio is based on the fact that the forward and backward moving speed of the human hand with the same sense of strength is about 0.65 of the left and right moving speed, and the width of the computer screen is 0.75 of its length, and the intermediate value of 0.65 to 0.75 is taken. The second side length (M) 12 of the rectangular sensing array is calculated by an algorithm, and the rule is Nq+K(1-q), and the second side length 12 is 8 pixels by substituting the parameters. Please refer to FIG. 3 further. It can be seen from the above that when compared with the known technology, the area of the 10×8 rectangular sensing array is 20% less than that of the known 10×10 square sensing array. The saved pixels can be represented by N-M, the N-M=(1-q)×(N-K), when the ratio of the forward and backward movement speed to the left and right movement is fixed, the larger the first side length, or the longer the reference block side length The smaller the value of N-M is, the more pixels are saved. The comparison method of the rectangular sensing array is to utilize the whole area search method to first take a reference block 13 whose side length 14 is 4 pixels, and then take out a sample block 16 with the same size as the reference block 13. The sample blocks 16 are compared from left to right and top to bottom, and 35 sample blocks 16 can be compared, and the data comparison amount of the rectangular sensing array is smaller than that of the square sensing array. After comparison, a block closest to the reference block 13 can be obtained.

To sum up, the present invention determines the sensing array method of the hand-held image motion tracking sensor, which can save the area of the sensing array when the sensor is in use, save the manufacturing cost, the small amount of data comparison and the short processing time , and then make the production of the present invention more progressive, more practical, and more in line with the needs of users, which has indeed met the requirements of the invention patent application, and the patent application is filed according to law.

Claims (2)

1. A method for determining a sensing array of a hand-held image motion tracking sensor, characterized in that the sensing array is a rectangular sensing array, and the method for determining the sensing array at least includes the following steps: (1) determine that the length of the first side of the sensing array is N, and assume that the length of the second side of the sensing array is M; (2) Set a square reference block whose side length is K and the width W of each pixel; (3) Estimate the left and right maximum tracking speed V _{x_max} and the front and rear maximum tracking speed V _{y_max} , the left and right maximum tracking speed is V _{x_max} = (NK)/2×f×W, the front and rear maximum tracking speed V _{y_max} =(MK)/2 ×f×W, where f is the current frequency; (4) When having the same sense of strength, the forward and backward moving speed maintains a ratio q to the left and right moving speed, so V _{y_max} =q×V _{x_max} , namely (MK)/2×f×W=q×(NK)/ 2×f×W, and the left and right maximum tracking speed meets the maximum left and right swing speed of the hand; (5) Using the above formula, calculate the length M of the second side, and thus determine the induction array. 2. The method for determining the sensing array of the hand-held image motion tracking sensor according to claim 1, wherein the ratio is between 0 and 1.

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