Cigarette moisture distribution detection method and system

Abstract

The invention relates to a cigarette moisture distribution detection method and system, and belongs to the technical field of cigarette detection. The method comprises the following steps: determining a full-cigarette pixel map of a cigarette according to a low-field nuclear magnetic image of the cigarette to be detected, obtaining the moisture content of the full cigarette to be detected by utilizing a relationship between a pixel value of the cigarette and the moisture content, performing segmentation processing on the full-cigarette pixel map of the cigarette to be detected, calculating an average pixel value of each segment of the pixel map, and calculating the moisture content of the cigarette to be detected according to the average pixel value. According to the average pixel value of each section of to-be-detected cigarette and the moisture content of the whole to-be-detected cigarette, the moisture content corresponding to each section of to-be-detected cigarette is calculated, so that the moisture content distribution change condition of the to-be-detected cigarette is obtained. The method does not need to damage the cigarette, and the detection is more accurate.

Description

Technical Field

[0001] The invention relates to a cigarette moisture distribution detection method and system, belonging to the technical field of cigarette detection. Background Art

[0002] The moisture content of cigars is an important physical indicator for evaluating cigarettes and is closely related to the sensory quality of cigars. A low moisture content will increase the irritation of smoke to a certain extent, causing discomfort to consumers, while a high moisture content will lead to insufficient release of flavor components. The current method for testing the moisture content of cigarettes mainly uses the oven method, which requires destructive operations on the cigarettes for testing. After the cigarettes are destroyed, not only is the cost wasted, but also the detection will be inaccurate due to operational errors during the destructive operation. Therefore, the moisture content detection method in the prior art will not only destroy the cigarettes, but also the moisture content detection is not accurate due to operational errors. Summary of the invention

[0003] The purpose of the present invention is to provide a method and system for detecting moisture distribution in cigarettes, so as to solve the problem that the current detection of moisture content distribution requires the destruction of cigarettes and the detection is inaccurate.

[0004] To achieve the above object, the solution of the present invention includes:

[0005] A method for detecting moisture distribution in cigarettes of the present invention comprises the following steps:

[0006] The pixel map of the whole cigarette is determined according to the low-field nuclear magnetic resonance image of the cigarette to be tested, and the moisture content of the whole cigarette to be tested is obtained by using the relationship between the pixel value of the cigarette and the moisture content; the relationship between the pixel value of the cigarette and the moisture content is established by using the pixel value of the low-field nuclear magnetic resonance image of the test cigarette with known moisture content;

[0007] The pixel image of the entire cigarette to be tested is segmented, and the average pixel value of each segment of the pixel image is calculated. The moisture content of each segment of the cigarette to be tested is calculated based on the average pixel value of each segment of the cigarette to be tested and the moisture content of the entire cigarette to be tested, so as to obtain the change in the moisture content distribution of the cigarette to be tested.

[0008] Furthermore, the moisture content corresponding to each segment of the pixel image of the tested cigarette is equal to the ratio of the average pixel value of the segment to the average pixel value of the entire cigarette, and then multiplied by the moisture content of the entire cigarette.

[0009] Furthermore, the average pixel value of each segment of the cigarette to be tested is the pixel value after denoising, and the denoising processing steps are: taking the average value of the remaining pixels after removing the pixel image of the entire cigarette from the low-field nuclear magnetic resonance image of the cigarette to be tested as the pixel value of the noise, and subtracting the pixel value of the noise from the average pixel value of the cigarette to be tested after segmentation processing, to obtain the corresponding noise-free average pixel value.

[0010] Furthermore, the pixel image of the whole cigarette to be tested is obtained by extracting the edge contour of the cigarette using an edge detection algorithm and segmenting it according to the minimum circumscribed rectangular range of the edge contour.

[0011] Furthermore, the pixel image of the entire cigarette to be tested is segmented in an equidistant manner.

[0012] Beneficial effect: The method for detecting moisture distribution in cigarettes of the present invention, based on the existing detection method, obtains the pixel value of the whole cigarette through low-field nuclear magnetic resonance, and then uses the relationship between the pixel value and moisture content of the cigarette to obtain the moisture content of the whole cigarette, and then calculates the average pixel value of the pixel image of each segmented cigarette, and uses the average pixel value of each segment of the pixel image of the cigarette and the moisture content of the whole cigarette to calculate the moisture content of each segmented cigarette. Compared with the traditional method of detecting moisture content by destroying the cigarettes, this method does not need to destroy the cigarettes, and only uses the image processing method to process the pixel image of the cigarette to obtain the moisture content distribution. The detection accuracy is relatively high, and the relationship between pixel value and moisture content is used to more intuitively and accurately reflect the changing trend of moisture content.

[0013] A cigarette moisture distribution detection system of the present invention comprises an image acquisition unit and an image processing unit. The image acquisition unit is used to obtain a low-field nuclear magnetic resonance image of the cigarette to be detected, and the image processing module is used to process the image obtained by the image acquisition module to implement the cigarette moisture distribution detection method as described above.

[0014] Furthermore, the image acquisition unit acquires a low-field nuclear magnetic resonance image of the entire cigarette to be tested in a non-layered imaging mode according to a set signal-to-noise ratio.

[0015] Beneficial effects: The cigarette moisture detection system of the present invention can use the image acquisition unit and the image processing unit to complete the detection of the moisture distribution of the cigarette. It has a simple structure, does not need to destroy the cigarette, and can more intuitively and accurately reflect the changing trend of the moisture content. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is an imaging diagram of a cigarette scanned by low-field nuclear magnetic resonance in an embodiment of the method of the present invention;

[0017] Figure 2 is a pixel image of a whole cigarette in an embodiment of the method of the present invention;

[0018] Figure 3 is a graph showing the correlation between pixel average value and moisture content in an embodiment of the method of the present invention;

[0019] Figure 4 It is a curve diagram of pixel value and water content change in the method embodiment of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0021] The idea of ​​the present invention is to provide a method and system for detecting moisture distribution in cigarettes. The method mainly utilizes the relationship between the pixel value and moisture content of a cigarette. After obtaining a pixel image of the entire cigarette using a low-field nuclear magnetic resonance image of the cigarette to be tested, the moisture content of the entire cigarette is obtained. The pixel image of the entire cigarette is segmented, and the pixel average value of each segment is calculated respectively. The moisture content corresponding to each segment of the cigarette to be tested is calculated based on the average pixel value of each segment of the cigarette to be tested and the moisture content of the entire cigarette to be tested, so as to obtain the change in moisture content distribution of the cigarette to be tested.

[0022] Example of a method for detecting moisture distribution in cigarettes:

[0023] like Figures 1 to 4 A method for detecting moisture distribution of cigarettes is shown, which measures the moisture distribution of cigarettes by low-field nuclear magnetic resonance technology, obtains a moisture distribution image of cigarettes, and then obtains the correlation between cigarette pixels and moisture content, thereby more intuitively and accurately reflecting the changing trend of moisture content. The following is a specific implementation of this embodiment.

[0024] The pixel map of the whole cigarette is determined according to the low-field nuclear magnetic resonance image of the cigarette to be tested, and the moisture content of the whole cigarette to be tested is obtained by using the relationship between the pixel value and the moisture content of the cigarette.

[0025] The relationship between the pixel value and moisture content of a cigarette is established by using test cigarettes with known moisture content and the pixel values ​​of low-field nuclear magnetic resonance images of the test cigarettes.

[0026] Specifically, it is first necessary to use low-field nuclear magnetic resonance imaging to obtain a pixel image of the entire cigarette, such as Figure 1 The pixel image of the whole cigarette in the low-field nuclear magnetic resonance imaging image is obtained by using the edge detection operator. The edge contour of the cigarette in the edge detection operator is segmented according to the range of the minimum circumscribed rectangle of the contour, and then the following is obtained: Figure 2 The pixel values ​​of the whole cigarette are shown. There are many edge detection operators, such as findcontours function, CNNY, etc. The specific algorithm can be determined according to the actual situation.

[0027] The relationship between the pixel value and moisture content of a cigarette is obtained based on multiple tests. First, a test cigarette with a known moisture content is measured, and then the test cigarette is subjected to low-field nuclear magnetic resonance imaging, and the average pixel value of the cigarette area obtained in the low-field nuclear magnetic resonance image is calculated. The moisture content and the average pixel value of the test cigarette are linearly or nonlinearly fitted to obtain the fitting relationship between the moisture content and the pixel value. When the moisture content of a cigarette is measured using a low-field nuclear magnetic resonance imaging method, the different moisture areas are displayed differently on the imaging. The closer the area is to white, the higher the moisture content, and the larger the pixel value of the white area on the image, the pixel value can be used to be equivalent to the moisture content. Specifically, in order to ensure the accuracy of the moisture detection test of cigarettes, the cigarettes are placed in a set environment (for example, the temperature is 45°C and the RH value is about 80) for a certain period of time (such as 48 hours), the moisture content of the cigarettes is adjusted to the moisture content at the factory, and the cigarette samples are placed in the sample bin and placed in the temperature and humidity control probe. By controlling the temperature and humidity in the temperature and humidity control probe, cigarette samples with different temperatures and humidities are obtained. The waiting time of the imaging software was set to 10-30 ms, the signal-to-noise ratio was adjusted to 2, the imaging mode was set to non-stratified, and the imaging section was selected. The cigarette sample was scanned using the imaging software to obtain an average pixel map of the entire cigarette.

[0028] The pixel image of the entire cigarette to be tested is segmented, and the average pixel value of each segment of the pixel image is calculated. The moisture content of each segment of the cigarette to be tested is calculated based on the average pixel value of each segment of the cigarette to be tested and the moisture content of the entire cigarette to be tested, so as to obtain the change in the moisture content distribution of the cigarette to be tested.

[0029] Specifically, the full-pixel image divides the cigarette into n segments from top to bottom at equal distances, and then calculates the average pixel value I of each segment of the cigarette mean In this embodiment, the cigarette pixel image is divided into 10 segments.

[0030] When calculating the average pixel value of each segment of cigarettes, the pixel images of each segment of cigarettes are also affected by noise. In order to improve the detection accuracy and avoid the influence of noise, in this embodiment, when calculating the average pixel value of each segment of cigarette pixel images, it is necessary to subtract the influence of noise. Specifically, the average value of the remaining pixels after removing the pixel image of the whole cigarette from the low-field nuclear magnetic resonance image of the cigarette to be tested is used as the pixel value of the noise:

[0031]

[0032] In the formula, I zao is the noise pixel value, n is the number of segments divided into by the whole cigarette, I i It is the pixel value of the remaining part after removing the cigarette area.

[0033] Subtract the pixel value of noise from the average pixel value of each segment to get the final average pixel value:

[0034] I=I mean -I zao

[0035] A three-dimensional graph was drawn using the average pixel values ​​of each segment of the cigarette, the corresponding moisture content, and the drying time of the cigarette to obtain the moisture content changes of each segment of the cigarette.

[0036] The average value is calculated based on the average pixel value of each segment of the cigarette pixel image, and then the ratio of the pixel average value of each segment of the cigarette pixel image to the pixel average value of the entire cigarette is calculated. The moisture content corresponding to each segment of the cigarette pixel image is obtained by using the ratio of the pixel average value of each segment of the cigarette pixel image to the pixel average value of the entire cigarette and the overall moisture content of the cigarette:

[0037]

[0038] In the formula, m i is the moisture content of each segment of the cigarette, and m is the moisture content of the entire cigarette.

[0039] This embodiment also includes the determination of the moisture content of cigarettes at different drying times, and then obtains the moisture content change of the same cigarette at different drying times. The three-dimensional graph is drawn using the pixel average value of each segment of the cigarette pixel image, the moisture content of each segment, and the drying time. Figure 3 As shown in the figure, the change of moisture content of each cigarette pixel inside the cigarette at different drying times is obtained, where the drying time can be set according to the actual situation. The change of moisture content corresponding to the cigarette pixel map at different drying times can be used to more accurately and intuitively describe the moisture distribution of the cigarette.

[0040] In summary, the pixel value of the whole cigarette is obtained by low-field nuclear magnetic resonance, and the relationship between the pixel value and moisture content of the cigarette is used to obtain the moisture content of the whole cigarette. The average pixel value of the pixel image of each segmented cigarette is calculated, and the average pixel value of the pixel image of each segmented cigarette and the moisture content of the whole cigarette are used to calculate the moisture content of each segmented cigarette. Compared with the traditional method of detecting moisture content by destroying the cigarette, this method does not need to destroy the cigarette. Only the pixel image of the cigarette is processed by image processing method to obtain the moisture content distribution. The detection accuracy is relatively high. The relationship between pixel value and moisture content is used to more intuitively and accurately reflect the changing trend of moisture content.

[0041] Cigarette moisture distribution detection system embodiment:

[0042] The cigarette moisture distribution detection system in this embodiment includes an image acquisition unit and an image processing unit. The image acquisition unit is used to obtain a low-field nuclear magnetic resonance image of the cigarette to be detected, and the image processing module is used to process the image obtained by the image acquisition module to implement the above-mentioned cigarette moisture distribution detection method, wherein the implementation method has been specifically described in the cigarette moisture distribution detection method embodiment, and will not be repeated here.

[0043] The image processing module includes a memory, a processor and an internal bus, and the processor and the memory communicate and exchange data with each other through the internal bus. The memory includes at least one memory that can store image data acquired by the image acquisition module, and the processor executes various functional applications and data processing by running software programs and modules stored in the memory.

[0044] The processor may be a microprocessor MCU, a programmable logic device FPGA or other processing device.

[0045] The memory may be various memories that use electrical energy to store information, such as RAM, ROM, etc.; it may also be various memories that use magnetic energy to store information, such as hard disks, floppy disks, magnetic tapes, magnetic core memories, bubble memories, USB flash drives, etc.; it may also be various memories that use optical methods to store information, such as CDs, DVDs, etc.; of course, it may also be other types of memories, such as quantum memories, graphene memories, etc.

Claims

1. A method for detecting moisture distribution in cigarettes, characterized in that: The following steps are involved: Determine the pixel map of the whole cigarette according to the low-field nuclear magnetic resonance image of the cigarette to be tested, and obtain the moisture content of the whole cigarette to be tested by using the relationship between the pixel value and the moisture content of the cigarette; The relationship between the pixel value and moisture content of a cigarette is established by using the pixel values ​​of the low-field nuclear magnetic resonance images of test cigarettes with known moisture content; The pixel image of the entire cigarette to be tested is segmented, and the average pixel value of each segment of the pixel image is calculated. The moisture content of each segment of the cigarette to be tested is calculated based on the average pixel value of each segment of the cigarette to be tested and the moisture content of the entire cigarette to be tested, so as to obtain the change in the moisture content distribution of the cigarette to be tested.

2. The method for detecting moisture distribution in cigarettes according to claim 1, characterized in that: The moisture content corresponding to each segment of the pixel image of the tested cigarette is equal to the ratio of the average pixel value of the segment to the average pixel value of the entire cigarette, and then multiplied by the moisture content of the entire cigarette.

3. The method for detecting moisture distribution in cigarettes according to claim 1, characterized in that: The average pixel value of each segment of the cigarette to be tested is the pixel value after denoising. The denoising processing steps are as follows: the average value of the remaining pixels after removing the pixel image of the entire cigarette from the low-field nuclear magnetic resonance image of the cigarette to be tested is used as the pixel value of the noise, and the average pixel value of the cigarette to be tested after segmentation processing is subtracted from the pixel value of the noise to obtain the corresponding average pixel value without noise.

4. The method for detecting moisture distribution in cigarettes according to claim 1, characterized in that: The pixel image of the whole cigarette to be tested is obtained by extracting the edge contour of the cigarette using an edge detection algorithm and segmenting it according to the minimum circumscribed rectangular range of the edge contour.

5. The method for detecting moisture distribution in cigarettes according to claim 1, characterized in that: The pixel image of the entire cigarette to be tested is segmented in an equidistant manner.

6. A cigarette moisture distribution detection system, characterized in that: It comprises an image acquisition unit and an image processing unit, wherein the image acquisition unit is used to obtain a low-field nuclear magnetic resonance image of the cigarette to be detected, and the image processing module is used to process the image obtained by the image acquisition module to implement the cigarette moisture distribution detection method as described in any one of claims 1 to 5.

7. The cigarette moisture distribution detection system according to claim 6, characterized in that: The image acquisition unit acquires the low-field nuclear magnetic resonance image of the whole cigarette to be tested in a non-layered imaging mode according to the set signal-to-noise ratio.

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