WO2019090556A1

WO2019090556A1 - Method for measuring size of object and mobile terminal

Info

Publication number: WO2019090556A1
Application number: PCT/CN2017/110095
Authority: WO
Inventors: 詹昌松
Original assignee: 深圳传音通讯有限公司
Priority date: 2017-11-09
Filing date: 2017-11-09
Publication date: 2019-05-16

Abstract

Provided are a method for measuring the size of an object and a mobile terminal. The method for measuring the size of an object comprises the following steps: a mobile terminal automatically focuses on a measured object and forms an image; obtain the image distance of the measured object; calculate the object distance of the measured object according to the preset focal length of the mobile terminal and the image distance; obtain the size of the image of the measured object; and calculate the size of the measured object. The technical solution achieves remote object size measurement without using other measuring tools, so that the time for measuring the size of an object is saved, and the working efficiency is improved.

Description

Method for measuring object size and mobile terminal

Technical field

The present invention relates to the field of mobile terminals, and in particular, to a method for measuring an object size and a mobile terminal.

Background technique

At present, mobile terminal devices such as smart phones and satellite phones have become an indispensable part of people's lives. The mobile terminal can store contact information for communication with contacts. With the development of the technology, the function of the mobile terminal is not limited to communication, and the camera function can be realized by integrating the camera device, and a digital photo is formed and stored in the mobile terminal. The prior art continuously improves the camera performance of the mobile terminal, such as increasing the number of pixels of the lens, or increasing the number of lenses. For example, the front and back sides of the mobile terminal are integrated with a camera to meet the self-photographing requirement.

However, on the basis of the shooting function of the mobile terminal, people have put forward more application requirements, in particular, it is desirable to be able to measure the size of an object by remote cameraing, without using other tools for measurement, for example, when performing express delivery. It can quickly know the size of the goods, so that the corresponding packaging box can be selected, which can provide great convenience for the logistics industry or companies or individuals who need to ship.

Therefore, it is necessary to provide a method for measuring the size of an object based on the mobile terminal, and can measure the size of the object to be measured without contacting the object to be measured, thereby facilitating subsequent packaging selection, metering and charging, and the like.

Summary of the invention

In order to overcome the above technical deficiencies, an object of the present invention is to provide a method for measuring an object size and a mobile terminal, which calculates an object to be measured and an image thereof by an imaging principle, and obtains a size of the object to be measured. .

In a first aspect of the invention, a method for measuring an object size is disclosed, the method for measuring an object size comprising the steps of:

A mobile terminal automatically focuses on an object to be measured and forms an image of the image;

Obtaining an image distance of the measured object;

Calculating an object distance of the measured object according to a preset focal length and the image distance in the mobile terminal;

Obtaining an image size of the image to be measured;

Calculating the size of the measured object.

Preferably, the step of the mobile terminal automatically focusing on an object to be measured and forming an image of the image comprises:

The mobile terminal performs an imaging operation on the measured object to obtain an image of the image;

Calculating the sharpness of the imaged image using a focus evaluation function;

Determining whether the resolution is greater than or equal to a definition threshold preset in the mobile terminal;

Stopping the auto focus when the sharpness is greater than or equal to the sharpness threshold;

When the sharpness is smaller than the sharpness threshold, the image distance of the measured object is adjusted, and the imaging operation step, the sharpness calculation and the determining step are repeated.

Preferably, adjusting the image distance of the mobile terminal is achieved by adjusting a distance between a lens of the mobile terminal and an imaging position of the measured object.

Preferably, when the distance between the lens of the mobile terminal and the imaging position of the measured object is adjusted, it is adjusted by manual mechanical adjustment or electric motor.

Preferably, when acquiring the image distance of the measured object, the distance between the imaging position of the measured object and the lens of the mobile terminal is detected by a first distance sensor.

Preferably, after the step of calculating the size of the measured object, the method for measuring the size of the object further comprises the following steps:

Displaying an image and size of the object to be measured on a display interface of the mobile terminal.

Preferably, the step of calculating the object distance of the measured object according to the focal length of the mobile terminal and the image distance is replaced by:

A second distance sensor on the mobile terminal detects a distance between the mobile terminal and the measured object to obtain an object distance.

According to a second aspect of the present invention, a mobile terminal includes a memory, a processor, a communication module, a camera module, an imaging module, a first distance sensor, and a computer program stored on the memory and operable on the processor. The processor implements the following steps when executing the computer program:

The camera module automatically focuses on an object to be measured and forms an image on the imaging module;

Obtaining an image distance of the measured object from the camera module;

The processor calculates an object distance of the measured object according to a focal length of the mobile terminal and the image distance;

Obtaining, by the processor, an imaging size of the measured object from the imaging module;

The processor calculates a size of the measured object.

Preferably, the photographing module comprises an electric motor, and the electric motor adjusts a distance between the lens and the imaging module in the photographing module.

Preferably, the mobile terminal further includes a second distance sensor, and the second distance sensor detects a distance between the mobile terminal and the measured object to obtain an object distance.

After adopting the above technical solution, compared with the prior art, the following beneficial effects are obtained:

1. Achieve remote object size measurement without the need for other measurement tools;

2. Save the object size measurement time and improve work efficiency.

DRAWINGS

1 is a flow chart showing a method for measuring an object size in accordance with an embodiment of the present invention;

2 is a schematic flow chart of a method for measuring an object size according to another embodiment of the present invention;

3 is a schematic flow chart of step S101 of FIG. 1 in accordance with an embodiment of the present invention;

4 is a structural block diagram of a mobile terminal for measuring an object size in accordance with an embodiment of the present invention;

5 is a structural block diagram of a mobile terminal for measuring an object size in accordance with another embodiment of the present invention;

Figure 6 is a schematic diagram of imaging in accordance with an embodiment of the present invention.

Reference mark:

10-Mobile terminal, 11-memory, 12-processor, 13-photographing module, 14-communication module, 15-display module, 16-imaging module, 17-first distance sensor, 18-second distance sensor.

Detailed ways

Advantages of the present invention are further explained below in conjunction with the accompanying drawings and specific embodiments.

Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. The following description refers to the same or similar elements in the different figures unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with aspects of the present disclosure as detailed in the appended claims.

The terms used in the present disclosure are for the purpose of describing particular embodiments only, and are not intended to limit the disclosure. The singular forms "a", "the" and "the" It should also be understood that the term "and/or" is used herein. Means and includes any or all possible combinations of one or more associated listed items.

It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, the first information may also be referred to as second information without departing from the scope of the present disclosure. Similarly, the second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "when" or "in response to a determination."

In the description of the present invention, it is to be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientation or positional relationship of the indications of "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present invention and simplifying the description, rather than It is to be understood that the device or elements referred to have a particular orientation, are constructed and operated in a particular orientation and are therefore not to be construed as limiting.

In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "mounted", "connected", and "connected" are to be understood broadly, and may be, for example, mechanical or electrical, or both. The internal communication of the components may be directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms may be understood according to specific circumstances.

In the following description, the use of suffixes such as "module", "component" or "unit" for indicating an element is merely an explanation for facilitating the present invention, and does not have a specific meaning per se. Therefore, "module" and "component" can be used in combination.

1 is a schematic flow chart of a method for measuring an object size according to an embodiment of the present invention, the method comprising the following steps:

S101: A mobile terminal 10 automatically focuses on an object to be measured and forms an image of an image.

The implementation of the method is based on a mobile terminal 10 having a camera function, and the mobile terminal 10 is provided with an auto focus function. In this step, the mobile terminal 10 automatically focuses on an object to be measured and forms an image of the image. In this embodiment, the mobile terminal 10 performs focusing by a single camera. The camera has a lens group therein, and the light reflected by the measured object forms an image by the lens group in the camera. The camera may also include only one lenticular lens sheet for the photographing operation.

According to the principle of convex lens imaging, the distance between the object to be measured and the convex lens, that is, the object distance, when the object distance is greater than 2 times the focal length, is an inverted and reduced real image on the other side of the convex lens, the real image and the convex lens The distance is the image distance. In the embodiment, the autofocus is implemented by adjusting the image distance when the focal length and the object distance are constant, so that the imaged image reaches the clearest state, that is, the imaged image detected by the mobile terminal 10. The position is exactly at the position of the real image of the object to be measured. When the object distance changes, the image distance should be adjusted in real time to satisfy the imaging. The image is clearly required to achieve autofocus.

For a lens group composed of a plurality of lenses, the autofocus principle is similar to the single convex lens imaging focusing principle, and the image distance is adjusted to achieve an optimal imaging image. The camera is movable, that is, a "scalable" movement seen from the outside.

S102: Acquire an image distance of the measured object.

The acquisition of the image distance is the basis for realizing the subsequent steps of calculating the size of the measured object. A first distance sensor 17 is disposed in the mobile terminal 10, and the first distance sensor 17 detects a distance of the camera to an imaging position. The first distance sensor 17 may be an infrared sensor or an ultrasonic sensor, and directly performs distance detection and transmission to the processor 12; or may be a contact detection point disposed on a moving path of the camera, the contact type The detection point may be a piezoelectric material, and each of the contact detection points presets a corresponding image distance parameter, and the moving position of the camera can be perceived by acquiring the state of the different contact detection points, thereby obtaining the image distance.

S103: Calculate an object distance of the measured object according to a preset focal length and the image distance in the mobile terminal 10.

In this step, the object distance of the measured object is calculated by the convex lens imaging principle, and the calculation formula is:

Where f is the focal length, v is the image distance, and u is the object distance. In this embodiment, the focal length of the camera is a constant parameter, which is preset in the mobile terminal 10, and the image distance has been acquired in step S102, so the object distance of the measured object can be calculated.

S104: Acquire an image size of the image of the measured object.

The light emitted by the measured object is imaged in the mobile terminal 10 through the camera to form an image, which is optical imaging. In this step, the size of the optically imaged image is acquired. The optically imaged image is first formed on a photosensitive element within the mobile terminal 10 and then converted into an image format in a digital format, represented by pixels, the size of the imaged image of the digital format and its inclusion The number of pixels is related. Corresponding relationship between the range of pixel points of the imaged image of the digital format preset in the mobile terminal 10 and the size of the imaged image of the optical imaging, the correspondence relationship being a linear relationship. For example, in a digital format, the imaged image has a pixel point range of 100*100, and the corresponding optically imaged image has a size of 1 cm*1 cm; similarly, a digital format image corresponding to a pixel range of 200*200 corresponds to The image size of the optical imaging image is 2 cm * 2 cm. The correspondence relationship is affected by parameters of the photosensitive element of the mobile terminal 10, the conversion circuit, and the resolution of the display screen.

To achieve the pixel point range of the imaged image in the digital format, the boundary contour of the imaged image can be identified by image recognition, thereby obtaining its pixel point range.

S105: Calculate the size of the measured object.

Referring to FIG. 6 , which is a schematic diagram of the convex lens imaging in the embodiment, it can be seen that the contour of the measured object is the line segment AB, the contour of the image is the line segment CD, the center point of the convex lens is O, and the object distance of the measured object is For the line segment BO, the image distance of the imaged image is the line segment DO, and the line segment AB is parallel to the line segment CD. Among them, using the principle of apex angle similarity can prove that the triangle AOB is similar to the triangle COD, then there is the following formula:

Wherein the object distance BO is obtained in step S103, the image distance DO is obtained in step S104, and the size CD of the imaged image is obtained in step S104, and finally the size AB of the measured object can be obtained.

The outer contour of the measured object is composed of a plurality of sets of line segments, and the length of all the contour segments can be calculated by this step, or the critical dimension can be obtained according to the geometric features of the measured object, such as the height of the triangle, the radius of the circle, and the like. size.

As a further improvement of the method for measuring the size of an object, after the step S105, the method for measuring the size of the object by the user further comprises the following steps:

S106: Display an image and size of the image of the measured object on a display interface of the mobile terminal 10.

This step performs a display operation to display the size of the object to be measured to the user. After the step S105 calculates the size of the measured object, the user needs to know the measurement result, and the size of the measured object can be displayed while displaying the imaged image on the display interface of the mobile terminal 10. . The size of the object to be measured is displayed in the form of a number plus a unit.

Referring to FIG. 2, which is a schematic flowchart of a method for measuring an object size according to another embodiment of the present invention, step S103 is replaced by:

Step S107: The second distance sensor 18 on the mobile terminal 10 detects the distance between the mobile terminal 10 and the measured object to obtain an object distance.

In this embodiment, the object distance is obtained by using a direct measurement method. When the user uses the mobile terminal 10 to shoot the object to be measured, the mobile terminal 10 is facing the object to be measured, and the use of the object is provided. The second distance sensor 18 performs a condition of distance detection. The second distance sensor 18 may be an infrared sensor, an ultrasonic sensor, and the distance information of the detected mobile terminal 10 and the measured object is transmitted to the processor 12 to acquire the object distance.

Referring to FIG. 3, which is a schematic flowchart of step S101 in FIG. 1 according to an embodiment of the present invention, step S101 includes:

Step S101-1: The mobile terminal 10 performs an imaging operation on the measured object to obtain an imaged image.

This step performs an imaging operation, that is, the light reflected by the measured object is projected through the camera of the mobile terminal 10 An optically imaged image is formed onto the photosensitive element within the mobile terminal 10. The optically imaged image is then converted by the photosensitive element and the conversion circuit into an imaged image in digital format.

Step S101-2: Calculating the sharpness of the imaged image using a focus evaluation function.

This step performs a sharpness calculation, and uses the focus evaluation function to perform a sharpness calculation on the imaged image of the digital format obtained in the step S101-1. The imaged image in the digital format represents the image in pixel information, and accordingly, the focus evaluation function calculates the pixel information to obtain a sharpness value. The focus evaluation function can be implemented by various algorithms, such as a gray gradient algorithm, a frequency domain analysis method, a statistical function, etc., wherein the gray gradient algorithm includes a Laplacian algorithm, a gray variance operator method, Gradient vector square function, difference absolute value sum method, Robert operator, S0be1 operator method, etc.

Step S101-3: determining whether the resolution is greater than or equal to a sharpness threshold preset in the mobile terminal.

A resolution threshold is preset in the mobile terminal for determining whether the resolution of the imaged image meets a focus requirement. The resolution calculated in the step S101-2 is a single dimension value, so that numerical comparison can be performed.

Step S101-4: When the sharpness is greater than or equal to the sharpness threshold, the autofocus is stopped.

When the determination of the step S101-3 is established, that is, the sharpness is greater than or equal to the sharpness threshold, this step performs the stop of the autofocus operation, records the current imaged image as the final imaged image, and then performs step S102.

Step S101-5: When the sharpness is smaller than the sharpness threshold, adjust the image distance of the measured object, and repeat step S101-1, step S101-2, and step S101-3.

When the step S101-3 determines that the determination is not true, that is, the resolution is less than the resolution threshold, the step is performed. In this step, the image distance of the measured object is adjusted, that is, the distance between the optically imaged image and the camera is adjusted to find the optimal imaging position. After the execution of this step, the process proceeds to step S101-1 to continue the next imaging, definition calculation, that is, until the resolution is greater than the definition threshold, and proceeds to step S101-4 to end the autofocus.

As a further improvement of the computer program, when the image distance of the measured object is adjusted in the step S101-5, the distance between the lens of the mobile terminal 10 and the imaging position of the measured object is adjusted. The camera of the mobile terminal 10 includes a lens, and adjusts the distance between the lens and the imaging position, that is, adjusts the image distance. In this embodiment, the method of adjusting the focus is adopted, that is, the focal length of the lens is inconvenient, and the image is changed by changing the image distance. The image forming position is actually the position of the photosensitive member, and the photosensitive member is generally fixed in the mobile terminal 10, and the movable member is the lens.

As a further improvement of the method for measuring the size of an object, when the distance between the lens of the mobile terminal 10 and the imaging position of the object to be measured is adjusted, it is adjusted by manual mechanical adjustment or electric motor. The present modified embodiment provides a way of adjusting the distance between the lens and the imaging position, which is actually the manner in which the lens is moved. One way is manual mechanical mode, that is, the user manually operates the lens to change the distance between the lens and the imaging position. The optical camera commonly used in life adopts manual mechanical mode to adjust the lens position. The other is an electric motor adjustment, and the mobile terminal 10 incorporates an electric motor capable of driving the lens to be stretched or contracted in the optical path direction, thereby changing the position of the lens and the photosensitive member. The mobile terminal 10 is provided with an operation button that allows the user to click a button to make adjustments.

As a further improvement of the method for measuring an object size, when an image distance of the measured object is acquired, an imaging position of the measured object and a lens of the mobile terminal 10 are detected by a first distance sensor 17 distance. The improved embodiment detects the image forming position, that is, the position of the photosensitive member and the lens, by the first distance sensor 17. The first distance sensor 17 may be a non-contact distance sensor such as an ultrasonic sensor or an infrared sensor, or a touch sensor may be used. For example, a line type resistor is disposed on the movement track of the lens, and a metal protrusion is disposed on the lens. In contact with the linear resistor, when the lens moves, a resistance value between one end of the linear resistor and the metal bump changes, thereby acquiring a moving position of the lens. Corresponding relationship between the resistance value and the lens position is pre-stored in the mobile terminal 10.

Referring to FIG. 4, which is a structural block diagram of a mobile terminal 10 for measuring an object size according to an embodiment of the present invention, the mobile terminal 10 includes:

- processor 12

The processor 12 is a core component of the mobile terminal 10, that is, a CPU, and can perform high-speed operations, process various tasks, and run a computer program.

-Memory 11

The memory 11 stores the computer program, as well as data, pictures, video files, audio files, contacts, and the like required for the computer program to run. The processor 12 can acquire various data required for operation from the memory 11.

-Photographing module 13

The camera module 13 is disposed in the mobile terminal 10, and includes an optical component such as a camera and a shutter. The camera includes a lens, and the lens may be a single mirror lens or a lens group composed of a plurality of lenses.

-Communication module 14

The communication module 14 is a module for communication connection with the outside, and may be a wireless network card (wifi module), a mobile bee. The socket communication module, Bluetooth module and other types can be connected to different networks according to the application. The communication module 14 can receive communication information sent from the outside, and can also send the communication information outward.

- display module 15

The display module 15 is an important component of the mobile terminal 10, and displays various functional interfaces to the user. In particular, when the display module 15 includes a touch screen, it can also receive input operations of the user. The display module 15 displays various prompt information to the user. The display module 15 displays the imaged image in the digital format and the size of the object to be measured.

- imaging module 16

The imaging module 16 is used in combination with the camera module 13 and includes a photosensitive element and a conversion circuit. The photosensitive element receives an optically imaged image formed by the camera module 13 and is converted into a digital format by the conversion circuit. Imaging images. Photosensitive elements are the core of imaging technology. There are two types: one is a widely used CCD (charge-coupled) device; the other is a CMOS (complementary metal oxide conductor) device.

- first distance sensor 17

The first distance sensor 17 is configured to detect a distance between an imaging position of the measured object and a lens of the mobile terminal 10. The first distance sensor 17 may be a non-contact distance sensor such as an ultrasonic sensor or an infrared sensor, or a touch sensor may be used. For example, a line type resistor is disposed on the movement track of the lens, and a metal protrusion is disposed on the lens. In contact with the linear resistor, when the lens moves, a resistance value between one end of the linear resistor and the metal bump changes, thereby acquiring a moving position of the lens. Corresponding relationship between the resistance value and the lens position is pre-stored in the mobile terminal 10. The first distance sensor 17 transmits the detected distance parameter to the processor 12 to acquire the image distance.

As a further improvement of the mobile terminal 10, the photographing module 13 includes an electric motor that adjusts a distance between a lens and the imaging module in the photographing module.

Referring to FIG. 5, which is a structural block diagram of a mobile terminal 10 for measuring an object size according to another embodiment of the present invention, the mobile terminal 10 further includes:

- second distance sensor 18

The second distance sensor 18 detects the distance between the measured object and the mobile terminal 10 in a non-contact manner. The second distance sensor 18 may be an infrared sensor, an ultrasonic sensor, and the distance information of the detected mobile terminal 10 and the measured object is transmitted to the processor 12 to acquire the object distance.

The mobile terminal 10 can be implemented in various forms. For example, the terminal described in the present invention may include, for example, a mobile phone, a smart phone, a notebook computer, a PDA (Personal Digital Assistant), a PAD (Tablet), a PMP (portable multiple Mobile terminals of media players, navigation devices, and the like, as well as fixed terminals such as digital TVs, desktop computers, and the like. In the following, it is assumed that the terminal is a mobile terminal. However, those skilled in the art will appreciate that configurations in accordance with embodiments of the present invention can be applied to fixed type terminals in addition to components that are specifically for mobile purposes.

It should be noted that the embodiments of the present invention are preferred embodiments, and are not intended to limit the scope of the present invention. Any one skilled in the art may use the above-disclosed technical contents to change or modify the equivalent embodiments. Any modification or equivalent changes and modifications of the above embodiments in accordance with the technical spirit of the present invention are still within the scope of the technical solutions of the present invention.

Claims

A method for measuring an object size, comprising the steps of:

A mobile terminal automatically focuses on an object to be measured and forms an image of the image;

Obtaining an image distance of the measured object;

Calculating an object distance of the measured object according to a preset focal length and the image distance in the mobile terminal;

Obtaining an image size of the image to be measured;

Calculating the size of the measured object.
A method for measuring an object size according to claim 1, wherein

The step of a mobile terminal automatically focusing on an object to be measured and forming an image of the image includes:

The mobile terminal performs an imaging operation on the measured object to obtain an image of the image;

Calculating the sharpness of the imaged image using a focus evaluation function;

Determining whether the resolution is greater than or equal to a definition threshold preset in the mobile terminal;

Stopping the auto focus when the sharpness is greater than or equal to the sharpness threshold;

When the sharpness is smaller than the sharpness threshold, the image distance of the measured object is adjusted, and the imaging operation step, the sharpness calculation and the determining step are repeated.
A method for measuring an object size according to claim 2, wherein

Adjusting the image distance of the mobile terminal is achieved by adjusting a distance between a lens of the mobile terminal and an imaging position of the measured object.
A method for measuring an object size according to claim 3, wherein

When the distance between the lens of the mobile terminal and the imaging position of the object to be measured is adjusted, it is adjusted by manual mechanical adjustment or electric motor.
A method for measuring an object size according to any one of claims 1 to 4, characterized in that

When acquiring the image distance of the measured object, the distance between the imaging position of the measured object and the lens of the mobile terminal is detected by a first distance sensor.
A method for measuring an object size according to any one of claims 1 to 4, characterized in that

After the step of calculating the size of the object to be measured, the method for measuring the size of the object further includes the following steps:

Displaying an image and size of the object to be measured on a display interface of the mobile terminal.
A method for measuring an object size according to any one of claims 1 to 4, characterized in that

The step of calculating the object distance of the measured object according to the focal length of the mobile terminal and the image distance is replaced by:

A second distance sensor on the mobile terminal detects a distance between the mobile terminal and the measured object to obtain an object distance.
A mobile terminal includes a memory, a processor, a communication module, a camera module, an imaging module, a display module, a first distance sensor, and a computer program stored on the memory and operable on the processor, wherein the processing The following steps are implemented when the computer program is executed:

The camera module automatically focuses on an object to be measured and forms an image on the imaging module;

Obtaining an image distance of the measured object from the camera module;

The processor calculates an object distance of the measured object according to a focal length of the mobile terminal and the image distance;

Obtaining, by the processor, an imaging size of the measured object from the imaging module;

The processor calculates a size of the measured object.
The mobile terminal of claim 8 wherein:

The photographing module includes an electric motor that adjusts a distance between a lens and the imaging module in the photographing module.
A mobile terminal according to claim 8 or 9, wherein

The mobile terminal further includes a second distance sensor, and the second distance sensor detects a distance between the mobile terminal and the measured object to obtain an object distance.