CN102810027B - Optical input device and control method - Google Patents

Abstract

An optical input device and a control method thereof, the control method comprises the following steps: sequentially capturing a reference image and a current image according to the time sequence, and calculating a displacement vector by using the position change of a specific pattern of the reference image and the current image; (b) calculating the geometric center of the specific pattern of the reference image and the geometric center of the specific pattern of the current image; (c) if the geometric centers of the specific patterns of the reference image and the current image are the same, calculating the proportion of the specific patterns between the reference image and the current image; (d) judging whether the proportion is kept unchanged, if the proportion is unchanged, outputting the displacement vector, and if the proportion is changed, not outputting the displacement vector or not acting; therefore, the optical input device does not output displacement vectors or does not act when not in the operation surface.

Description

Optical input device and control method

technical field

The invention relates to an input device and a control method, in particular to an optical input device and a control method that can stop outputting a displacement vector when it is not on the operation surface.

Background technique

Referring to FIG. 1 , the mouse is the computer input device most commonly used by users. The existing optical mouse 9 has a housing 90 , a light source 91 , a lens 92 , an image sensor 93 and a processing unit 94 .

The optical mouse 9 utilizes the image sensor 93 and the processing unit 94 to replace the mechanical structure of the wheel mouse on the hardware. At present, there is also a product of the integrated optical mouse control chip of the image sensor 93 and the processing unit 94; the operating principle of the optical mouse 9 is: The light source 91 emits light, which is reflected on an operating surface 8, and the reflected light passes through the lens 92, and the image sensor 93 made of a semiconductor chip is taken, and each time the picture is taken is about hundreds of frames (frame)/second The above is sent to the processing unit 94 for calculation of the displacement vector.

The calculation method of the processing unit 94 for the displacement vector is mainly to obtain two images in time sequence, first select a pattern of a region of interest (Region of Interest, referred to as ROI) from the first image, and then find the pattern in the second image that matches After finding the same pattern in the target area, it is judged where the pattern in the target area of the first image is moved to the second image and then a displacement vector is calculated. The calculation method of the displacement vector can be estimated by correlation. The measurement method judges the position change of the pattern on the first image and the second image to obtain a displacement vector.

Regarding the aforementioned correlation estimation method, reference can be made to the content disclosed in relevant patent technologies such as U.S. Patent No. 5,644,139, or there are other options, such as the block match method, which can be based on a comparison function (such as mean square error MSE( meansquared error) or absolute value average method MAD (mean absolute difference) to obtain the displacement vector.

Since the optical mouse 9 generally only operates on a horizontal plane, the processing unit 94 of the optical mouse 9 can only perform calculations on the displacement vectors in the X and Y directions (ie, on the horizontal plane), and will not perform the calculation based on the ratio of the specific pattern of the image. Judgment away from the operation surface 8.

Contents of the invention

In view of the moment when the optical input device is not on the operating surface, the specific pattern of the detected image will produce a proportional change. Therefore, the purpose of the present invention is to provide a method for judging that the specific pattern of the detected image is not in the An operation surface, and an optical input device and a control method that can stop outputting a displacement vector when it is not on the operation surface.

In the control method of the optical input device of the present invention, the optical input device moves on an operation surface and captures images of the operation surface at regular intervals; the method includes the following steps: (a) receiving images sequentially according to the capture time A reference image and a current image, using the position changes of a specific pattern in the reference image and the current image to calculate a displacement vector; (b) calculating the geometric center of the specific pattern in the reference image and the geometric center of the specific pattern in the current image; ( c) If the geometric center of the specific pattern in the reference image is the same as the current image, calculate the ratio of the specific pattern in the reference image to the current image; (d) determine whether the ratio remains unchanged, and if the ratio remains unchanged, output the displacement vector, If the scale is changed, no displacement vector is output or no action is taken.

Preferably, step (b) is to locate the outermost feature points according to the specific pattern of the reference image and the specific pattern of the current image and calculate the geometric centers of the feature points.

Preferably, step (c) is to determine the ratio of the specific pattern in the reference image to the current image based on the distance ratio between each feature point of the specific pattern in the reference image and the specific pattern in the current image to the geometric center.

The optical input device of the present invention is used to move on an operation surface, and the optical input device includes an image sensing module, a processing module and a transmission module.

The image sensing module captures the image of the operation surface at intervals and outputs a reference image and a current image in sequence according to the capture time.

The processing module includes an analog-to-digital conversion module for converting the analog image signal captured by the image sensing module into digital data and an operation module; the operation module has an image processing unit, a displacement calculation unit, and an error prevention processing unit. unit and an interface unit.

The image processing unit obtains a specific pattern from the reference image and the current image.

The displacement calculation unit calculates a displacement vector by using the position change of the specific pattern.

The anti-error processing unit calculates the geometric center of the specific pattern in the reference image and the geometric center of the specific pattern in the current image, and if the geometric center of the specific pattern in the reference image and the current image is the same, calculates the ratio of the specific pattern in the reference image to the current image , and judge whether the ratio remains unchanged, if the ratio remains unchanged, output the displacement vector, and if the ratio changes, do not output the displacement vector or take no action.

The interface unit receives the displacement vector output by the anti-error processing unit, and converts the displacement vector into interface specification data according to a predetermined interface specification.

The transmission module outputs the interface specification data output by the processing module.

Preferably, the anti-error processing unit locates the outermost feature points according to the specific pattern of the reference image and the specific pattern of the current image, and calculates the geometric centers of the feature points.

Preferably, the anti-error processing unit determines the ratio of the specific pattern in the reference image to the current image according to the distance ratio between each feature point of the specific pattern in the reference image and the specific pattern in the current image to the geometric center.

Preferably, the optical input device is a pen-type input device.

The beneficial effects of the present invention are: when the concept of an optical mouse is applied to a pen-type input device, it can be known whether it is on the operation surface by judging the proportional relationship of the pattern in the image, and if it is not on the operation surface, the original output is maintained or no action is taken.

Description of drawings

Fig. 1 is a schematic diagram illustrating an existing optical mouse;

Figure 2 is a unit block diagram illustrating a preferred embodiment of the optical input device of the present invention;

Fig. 3 is a schematic diagram illustrating that the optical input device touches a specific pattern in the image detected on the operation surface;

Fig. 4 is a schematic diagram illustrating a specific pattern in an image detected by the optical input device vertically not on the operating surface;

Fig. 5 is a schematic diagram illustrating the distance from each feature point to the geometric center position under the same geometric center according to the specific pattern of the reference image as shown in Fig. 3 and the specific pattern of the current image as shown in Fig. 4;

FIG. 6 is a flowchart illustrating a preferred embodiment of the control method of the optical input device of the present invention.

Detailed ways

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

Fig. 2 is a preferred embodiment of the present invention.

In a preferred embodiment of the present invention, the optical input device 100 is a pen-type input device, including a pen tool 10, a light source module 11, an image sensing module 12, a power supply module 13, a processing module 2, A transmission module 3 and a memory module 4 .

The light source module 11, the image sensor module 12, the power module 13, the processing module 2, the transmission module 3 and the memory module 4 are built inside the pen tool 10, and are used to move on an operation surface 6, and the power module 13 supplies all components. Electricity is required; the light source module 11 emits light, which is reflected on the operating surface 6, and the reflected light passes through the lens (not shown) to be received by the image sensing module 12, and sent to the processing module 2 for calculation. Wide-range image, the lens of this embodiment adopts wide-angle lens.

The image sensing module 12 captures the image of the operation surface 6 at regular intervals and outputs an analog image signal of a reference image and a current image captured successively in time sequence to the processing module 2; the processing module 2 includes an image to be captured. An analog-to-digital conversion module 21 and an operation module 22 for converting analog image signals into digital signals. The operation module 22 has an image processing unit 221, a displacement calculation unit 222, an error prevention processing unit 223, and an interface unit 224. Each component operates The principle is introduced as follows.

Referring to FIG. 2 to FIG. 4 , the image processing unit 221 obtains a specific pattern from the reference image 201 and the current image 202 , such as binarization processing.

The displacement calculation unit 222 calculates a displacement vector by using the position change of the specific pattern and temporarily stores it in the memory module 4. For the calculation of the displacement vector, for example: the block comparison method of the specific pattern of the target area can be used in the reference image 201 Obtain a specific pattern 41 (as shown in Figure 3), and obtain a specific pattern 42 (as shown in Figure 4) in the current image 202. However, the block comparison method of the specific pattern in the target area is only an example and not a limitation of many image processing methods. Other similar displacement vector calculation methods for specific pattern search also belong to the applicable category.

The anti-error processing unit 223 mainly uses the ratio of the pattern to determine whether to output the displacement vector, that is, when the ratio of the pattern remains unchanged, it means that the optical input device 100 is always on the operation surface 6, which belongs to normal operation, so the displacement vector can be output, but the pattern’s Once the ratio is changed, it means that the optical input device 100 is not on the operation surface 6 (including moving away or approaching), which is an abnormal operation, so no displacement vector is output, and its calculation method is introduced as follows.

First, calculate the geometric center (X ₀ , Y ₀ ) of the specific pattern 41 in the reference image 201 and the geometric center (X ₀ ′, Y ₀ ′) of the specific pattern 42 in the current image 202. The calculation method is based on the specific patterns 41, 42 Locate the outermost feature points and calculate the geometric center of the feature points, for example: take the three outermost feature point positions (X ₁ , Y ₁ ), (X ₂ , Y ₂ ), ( X ₃ , Y ₃ ) and the outermost three feature point positions (X ₁ ′, Y ₁ ′), (X ₂ ′, Y ₂ ′), (X ₃ ′, Y ₃ ′) of the specific pattern 42 and calculate The geometric centers of the feature points are calculated in the following formula 1 and formula 2.

$(x_0,Y_0)=(\frac{(x_1+x_2+x_3)}{3},\frac{(Y_1+Y_2+Y_3)}{3})$ Formula 1

$({x_0}^{\′},{Y_0}^{\′})=(\frac{({x_1}^{\′}+{x_2}^{\′}+{x_3}^{\′})}{3},\frac{({Y_1}^{\′}+{Y_2}^{\′}+{Y_3}^{\′})}{3})$ Formula 2

If the geometric center of the specific pattern 41 of the reference image 201 and the specific pattern 42 of the current image 202 are the same, as shown in formula 3.

(X ₀ ′, Y ₀ ′)=(X ₀ , Y ₀ ) Formula 3

In terms of calculating the ratio of the specific pattern 41 in the reference image 201 and the specific pattern 42 in the current image 202, this embodiment judges the specific patterns 41 and 42 based on the distance ratio k between each feature point of the specific pattern 41 and the specific pattern 42 to the geometric center position The ratio of , as shown in Equation 4.

$\frac{\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}{\sqrt{{<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; =</span>\frac{\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}{\sqrt{{<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}$

$<span\; class="notranslate">\; =</span>\frac{\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}{\sqrt{{<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; k</span>}$

Formula 4

Finally, judge whether the ratio remains unchanged. Assuming that the value after division is 1, which means that the ratio remains unchanged, the displacement vector will be output. If the ratio changes, for example, the value k after division is not 1, and the displacement will not be output. Vector or no action.

The interface unit 224 receives the displacement vector outputted by the error prevention processing unit 223 after judging and processing, and converts the displacement vector into interface specification data according to predetermined interface specifications, such as: PS/2 interface specification, USB interface specification, wireless transmission interface Specifications or any combination of the above generates interface specification data.

The transmission module 3 has a wired transmission unit 31 that processes the data including the displacement vector into a wired transmission signal and a wireless transmission unit 32 that processes the data including the displacement vector into a wireless transmission signal; the wired transmission unit 31 can output the interface unit 224 The interface specification data of the interface unit 224 is processed into a wired transmission signal for further processing by the back-end host 51. The wireless transmission unit 32 can transmit the wireless transmission signal, and the interface specification data output by the interface unit 224 is processed into a wireless transmission signal for supply to the remote host 51. The wireless receiving unit 52 realizes wired or wireless input function.

Referring to FIG. 6, and in conjunction with FIG. 2, using the aforementioned principles, the control method of the optical input device 100 of the present invention includes the following steps after the image sensing module 12 captures the image of the operation surface 6 at intervals: the processing module 2 The displacement calculation unit 222 receives a reference image and a current image (step 501) and calculates a displacement vector (step 502) by using the position change of the specific pattern of the reference image and the current image; then, the anti-error processing unit 223 calculates the reference image The geometric center of the specific pattern is the same as the geometric center of the specific pattern in the current image (step 503), and whether the geometric center of the specific pattern in the reference image and the current image is the same (step 504)? If 504 judges no, output the displacement vector (step 507), if it is the same, calculate the ratio of the specific pattern in the reference image to the current image (step 505), and determine whether the ratio remains unchanged (step 506)? If the ratio does not change, output the displacement vector (step 507); if the ratio changes, do not output the displacement vector or take no action (step 508).

To sum up, the effect of the optical input device 100 and the control method of the present invention is: when the concept of an optical mouse is applied to a pen-type input device, it can be determined whether the pattern is not on the operation surface 6 by judging the proportional relationship of the pattern. The proportions are the same, which means that the displacement vector is output when it is still on the operation surface 6. If the proportion of the pattern changes, it means that the displacement vector is not output or no action is maintained when it is not on the operation surface 6. It is very helpful for the continuity of writing or drawing, so it is true. Can reach the purpose of the present invention.

Claims (5)

1. A method for controlling an optical input device, the optical input device moves on an operation surface and captures images of the operation surface at intervals; it is characterized in that: the method comprises the following steps: (a) sequentially capturing a reference image and a current image in chronological order, and calculating a displacement vector by using a position change of a specific pattern in the reference image and the current image; (b) According to the specific pattern of the reference image and the specific pattern of the current image, respectively locate several feature points in the outermost periphery to calculate the geometric center of the specific pattern of the reference image and the geometric center of the specific pattern of the current image; (c) If the geometric center of the specified pattern in the reference image is the same as that in the current image, calculate the ratio of the specified pattern in the reference image to the current image; (d) Determine whether the ratio remains unchanged, if the ratio remains unchanged, output the displacement vector, and if the ratio changes, do not output the displacement vector or take no action. 2. The control method of the optical input device according to claim 1, characterized in that: step (c) is to determine the specific pattern according to the distance ratio between each feature point of the specific pattern of the reference image and the specific pattern of the current image to the geometric center position. The ratio of the pattern between the reference image and the current image. 3. An optical input device that moves on an operating surface, characterized in that: the optical input device includes: An image sensing module captures the image of the operation surface at regular intervals and outputs a reference image and a current image in sequence according to the capture time; A processing module includes an analog-to-digital conversion module for converting the analog image signal captured by the image sensing module into digital data and an operation module; the operation module has: an image processing unit, which obtains a specific pattern from the reference image converted into digital data by the analog-to-digital conversion module and the current image, a displacement calculation unit, which calculates a displacement vector by using the position change of a specific pattern, An anti-error processing unit, according to the specific pattern of the reference image and the specific pattern of the current image, respectively locate several feature points on the outermost periphery to calculate the geometric center of the specific pattern of the reference image and the geometric center of the specific pattern of the current image, if The geometric center of the specific pattern in the reference image is the same as the current image, calculate the ratio of the specific pattern in the reference image to the current image; and judge whether the ratio remains unchanged, if the ratio remains unchanged, output the displacement vector, if the ratio changes, do not output displacement vector or no action, An interface unit, receiving the displacement vector output by the anti-error processing unit, and converting the displacement vector into interface specification data according to a predetermined interface specification, A transmission module, which outputs the interface specification data output by the processing module. 4. The optical input device according to claim 3, characterized in that: the error prevention processing unit determines the specific pattern according to the distance ratio between each feature point of the specific pattern of the reference image and the specific pattern of the current image to the geometric center position The ratio of the reference image to the current image. 5. The optical input device according to any one of claims 3 to 4, characterized in that: the optical input device is a pen-type input device.