Method for rapidly and nondestructively detecting fruit surface glossiness of cattle and sheep-horn peppers

Abstract

The invention belongs to the technical field of glossiness detection, and particularly relates to a method for rapidly and nondestructively detecting the fruit surface glossiness of cattle and sheep-horn peppers, which comprises the following steps: S1, recording the reflected luminous flux of a glossiness plate by adopting the glossiness plate; s2, selecting a measurement site according to the surface type of the to-be-measured sample, measuring the site by using a glossmeter, and recording the reflection luminous flux of the measurement site; s3, calculating the glossiness of the measurement site; s4, correcting the glossiness of the measurement site to obtain the glossiness of the sample to be measured; and S5, correcting the glossiness according to the data correction model, and dividing the glossiness grade of the sample to be detected. The detection method disclosed by the invention is high in repeatability and high in precision, can realize rapid and nondestructive detection of a single fruit, and has a relatively good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of glossiness detection, and in particular relates to a method for quickly and non-destructively detecting the glossiness of the surface of red bell peppers and bell peppers. Background Art

[0002] Glossiness is not only an important appearance quality of vegetables but also a crucial economic trait. Fruits with high glossiness are easier to sell and command higher prices, leading to the need for quantitative evaluation. Conventional methods for evaluating fruit surface glossiness rely on visual perception and simple grading. This measurement relies on subjective judgment, is prone to significant errors, and lacks precise grading.

[0003] In recent years, there have been reports on technical research using instruments to measure the glossiness of vegetable fruit surfaces. Zhou Bingyu et al. peeled the outer skin of cucumber fruits and spread them flat, then measured the glossiness of the cucumber fruits using a gloss meter HYD-09. However, this measurement method is cumbersome and requires the outer skin of the fruit to be uniform and flat, which is destructive to the fruit and not conducive to large-scale measurement. Furthermore, patent CN106248634A, "A device and method for measuring the glossiness of the outer skin of fruit," uses an industrial camera to capture a clear image of the fruit being measured. The image is then processed, and the reflective area of ​​the fruit in the image is segmented based on the HIS model. The reflective intensity value is then calculated to obtain a gloss calibration matrix, which is then used to calibrate the glossiness of the cucumber fruit. This method is technically demanding and complex to operate.

[0004] There is a need to evaluate the glossiness of red bell peppers in the trade. However, there are currently no reports on a rapid, accurate, and non-destructive method for measuring the glossiness of red bell peppers.

[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for quickly and non-destructively detecting the glossiness of the surface of pimento and capsicum, which can more accurately detect the glossiness of the surface of pimento and capsicum.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for quickly and non-destructively testing the glossiness of the surface of shiitake mushrooms and bell peppers, comprising the following steps:

[0009] S1. Use a gloss plate and record its reflected luminous flux;

[0010] S2. Select the test area based on the surface type of the sample to be tested, measure the area using a gloss meter, and record the reflected light flux;

[0011] S3. Calculate the glossiness of the measurement point using the following formula:

[0012]

[0013] Where:

[0014] G i --The original measurement value of each test part, in GU;

[0015] Φ s --Reflected flux of the sample, in lm;

[0016] Φ os --The reflected luminous flux of the glossiness plate, in lm;

[0017] G os (60°)--The glossiness of the glossiness plate at an incident angle of 60°, the unit is GU;

[0018] S4. Introduce a compensation algorithm for special surface structures to correct the glossiness of the test area and obtain the glossiness of the sample to be tested. The correction model is as follows:

[0019]

[0020] Where:

[0021] G final --Glossiness value of the sample to be tested, in GU;

[0022] G i --Original value of each test part, unit is GU;

[0023] W i --regional weight coefficient;

[0024] C -- ridge depth, in mm;

[0025] K--smoothing coefficient 0.2.

[0026] S5. Classify the glossiness level of the sample to be tested according to the corrected glossiness.

[0027] Furthermore, in steps S1 and S2, the gloss meter has an incident angle θ of 60°, a window side length or diameter of no more than 5 mm, a measurement spot size of 2 mm × 4 mm, and a colorimetric response of CIE 1931 (2°) under CIE C light source.

[0028] Furthermore, in step S1 , the glossiness plate is a polished flat black glass plate, and within the visible light wavelength range and at an incident angle θ of 60°, its refractive index is 1.567, and its surface glossiness value is set to 100.

[0029] Furthermore, in step S2, if the surface of the sample to be tested is flat, three measuring points are evenly selected along the longitudinal axis of the fruit, and the corresponding regional weight distribution in step S4 is: equal weight, that is, 33.3% for each point.

[0030] Furthermore, in step S2, if the surface of the sample to be measured is of shallow ridge and groove type, 2 measuring points are located at the edges of the ridge and groove, and 1 measuring point is located at the ridge line, the corresponding regional weight distribution in step S4 is: 40%×2 for the ridge and groove area, and 20% for the ridge line.

[0031] Furthermore, in step S2, if the surface of the sample to be tested is of deep ridge / wrinkle type, 3 measurement points are located at the bottom of the ridge and 2 measurement points are located at the top of the wrinkle, and the corresponding regional weight distribution in step S4 is: 20% × 3 for the ridge area and 20% × 2 for the top of the wrinkle.

[0032] Furthermore, in step S4, the groove depth compensation value is increased by 0.5 GU for every 1 mm of depth.

[0033] Furthermore, in step S5, the classification criteria are as follows:

[0034]

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention selects measurement points based on the surface type of the sample to be tested. A gloss meter measures the reflected luminous flux at the corresponding locations. The result is compared with the gloss value and reflected luminous flux of a gloss plate to calculate the original gloss of the sample to be tested. A compensation algorithm is then introduced to correct the measured original gloss for specific surface structures, resulting in a corrected gloss value, which is the gloss of the sample to be tested. This method boasts high repeatability and accuracy, enabling rapid and nondestructive testing of single fruits, and has promising application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the optical principle diagram of the present invention;

[0038] Figure 2 This is the distribution map of measurement points on the flat surface of the cow / sheep horn pepper fruit;

[0039] Figure 3 This is the distribution map of measurement points on the surface of shallow ridged furrowed cow / sheep horn pepper fruit;

[0040] Figure 4 This is the distribution map of measurement points on the surface of the deep-ridged and furrowed cow / sheep horn pepper fruit;

[0041] Description of main reference numerals:

[0042] Figure 1 In the figure, θ1 is the incident angle of 60°; θ2 is the reflection angle of 60°; α1 is the incident angle (in the incident plane); α2 is the reflection angle (in the reflection plane); β1 is the incident angle (in the vertical plane); β2 is the reflection angle (in the vertical plane); S1 is the reflection stop; S2 is the reflection stop; S3 is the aperture stop;

[0043] Figure 2 In the figure, the red points are the measurement points;

[0044] Figure 3 In the figure, the red dots are the locations of the test parts, where point A is located at the edge of the groove with a weight of 40%; point B is located at the ridge line with a weight of 20%;

[0045] Figure 4 In the figure, the red dots are the locations of the test parts; point A is located at the bottom of the groove, with a weight of 20%; point B is located at the top of the wrinkle, with a weight of 20%. DETAILED DESCRIPTION

[0046] The following is a clear and complete description of the technical solution of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts are within the scope of protection of the present invention.

[0047] 1. Composition of the detection system

[0048] 1.1 Gloss measurement unit

[0049] Portable gloss meter (accuracy: ±0.5GU): incident angle θ is (60°), instrument performance is not less than Level 2 in JJG696; measurement window side length or diameter is not greater than 5mm; measurement spot: 2mm×4mm; CIE C light source, CIE1931 (2°) photometric response; equipped with gloss plate: polished flat black glass plate with a refractive index of 1.567 and a surface photometric value of 100 within the visible light wavelength range and an incident angle of 60°, meeting the working plate requirements in JJG696.

[0050] 1.2 Three-dimensional positioning module

[0051] Laser displacement sensor (resolution 0.01mm) is used to measure the depth of the fruit surface;

[0052] 2. Detection steps

[0053] 2.1 Instrument calibration

[0054] Constant temperature and humidity environment: temperature 23±2℃, humidity 50±5%RH.

[0055] 2.1.1 Preparation before calibration

[0056] Ensure that the calibration environment is free from direct sunlight, vibration, and electromagnetic interference;

[0057] Turn on the portable gloss meter and preheat for 15 minutes;

[0058] Dip a small amount of anhydrous ethanol in a dust-free cloth and gently wipe the surface of the gloss plate until it is completely dry.

[0059] 2.1.2 Zero point calibration

[0060] Align the measuring window of the portable gloss meter with the dedicated zero calibration plate and press the relevant key for zero point calibration.

[0061] 2.1.3 Gloss Plate Calibration

[0062] Place the measuring head of the portable gloss meter vertically on the gloss plate, press the relevant key, and after the instrument display value stabilizes, confirm that the error between the reading and the nominal value of the gloss plate is ≤±1GU.

[0063] Avoid direct contact with the gloss plate surface with your hands during the calibration process; keep the measurement window in close contact with the gloss plate during the calibration process to avoid tilting.

[0064] 2.2 Sample preparation

[0065] Select commercial shiitake / peppercorn fruit of uniform maturity, free of disease spots, insect bites, or mechanical damage. Gently wipe the surface three times in one direction with a dry microfiber cloth. Do not use liquid detergents. Place the instrument's test window on each test area of ​​the specimen, recording the test value for each area. The test area should comply with the requirements in Table 1.

[0066] Table 1 Measurement point selection

[0067] Surface type Number and distribution of measurement points Weight distribution Flat type 3 points (selected evenly along the vertical axis of the fruit) Equal weight (33.3% each) Shallow ridge type 3 points (2 points on the edge of the groove, 1 point on the ridge line) Ridge area 40% × 2, ridge line 20% Deep ridge / wrinkle type 5 points (3 points at the bottom of the groove, 2 points at the top of the wrinkle) 20% of the ridge and groove area × 3, 20% of the fold peak × 2

[0068] 2.3 Detection formula

[0069] 2.3.1 Calculation formula

[0070] Under the specified light source and incident angle θ, the glossiness of the measuring point is calculated by comparing the reflected luminous flux in the mirror direction of the surface of the cow / sheep horn pepper with the reflected luminous flux in the mirror direction of the reference standard plate. The calculation formula is as follows:

[0071]

[0072] Where:

[0073] G i --The original measurement value of each test part, in GU;

[0074] Φs --Reflected flux of the sample, in lm;

[0075] Φ os --The reflected luminous flux of the glossiness plate, in lm;

[0076] G os (60°)--The glossiness of the glossiness plate at an incident angle of 60°, the unit is GU;

[0077] 2.3.2 Data Correction

[0078] A compensation algorithm is introduced for special surface structures to correct the glossiness of the test area and obtain the glossiness of the sample to be tested. The correction model is as follows:

[0079]

[0080] Where:

[0081] G final --Glossiness value of the sample to be tested, in GU;

[0082] G i --Original value of each test part, unit is GU;

[0083] W i --regional weight coefficient;

[0084] C -- ridge depth, in mm;

[0085] K – smoothing coefficient 0.2.

[0086] 2.4 Rating Evaluation

[0087] Based on the glossiness range, beef / lamb horn peppers are divided into five grades: high gloss, medium-high gloss, medium gloss, medium-low gloss, and low gloss. The corresponding glossiness grades are shown in Table 2.

[0088] Table 2 Glossiness of Beef / Sheep Horn Pepper

[0089] grade Gloss level Gloss range (GU) Level 1 High gloss 25.0～30.0 Level 2 Medium-high gloss 20.0～24.9 Level 3 Medium gloss 15.0～19.9 Level 4 Medium-low gloss 10.0～14.9 Level 5 Low gloss 3.0～9.9

[0090] As can be seen from Table 2, the test results of the glossiness detection method of the present invention correspond to the sensory description, which is conducive to achieving rapid and non-destructive detection of single fruits.

[0091] In summary, the present invention selects measurement points based on the surface type of the sample to be tested, uses a gloss meter to measure the test area and obtain its reflected luminous flux. The result is compared with the gloss value and reflected luminous flux of a gloss plate to calculate the original gloss of the sample to be tested. A compensation algorithm is then introduced to correct the original gloss for the specific surface structure, resulting in the corrected gloss of the sample to be tested. This method is highly repeatable and accurate, enabling rapid and nondestructive testing of single fruits, and has promising application prospects.

[0092] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for quickly and non-destructively testing the glossiness of the fruit surface of cow and sheep horn peppers, characterized in that: The following steps are involved: S1. Use a glossiness plate and record its reflected luminous flux; S2. Select the test area based on the surface type of the sample to be tested, measure the area using a gloss meter, and record the reflected light flux; S3. Calculate the glossiness of the test area using the following formula: Where: G i --The original measurement value of each test part, in GU; Φ s --Reflected flux of the sample, in lm; Φ os --The reflected luminous flux of the glossiness plate, in lm; G os (60°)--The glossiness of the glossiness plate at an incident angle of 60°, the unit is GU; S4. Introduce a compensation algorithm for special surface structures to correct the glossiness of the test area and obtain the glossiness of the sample to be tested. The correction model is as follows: Where: G final --Glossiness value of the sample to be tested, in GU; G i --Original value of each test part, unit is GU; W i --regional weight coefficient; C--groove depth, in mm; K--smoothing coefficient 0.2; S5. Classify the glossiness level of the sample to be tested according to the corrected glossiness.

2. The method according to claim 1, characterized in that In steps S1 and S2, the gloss meter has an incident angle of θ (60°), a measurement window side length or diameter no greater than 5 mm, a measurement spot size of 2 mm × 4 mm, and a colorimetric response of CIE 1931 (2°) under CIE C light source.

3. The method according to claim 1, characterized in that In step S1 , the glossiness plate is a polished flat black glass plate, and within the visible light wavelength range and at an incident angle θ of 60°, its refractive index is 1.567, and its surface glossiness value is set to 100.

4. The method according to claim 1, wherein In step S2, if the surface of the sample to be tested is flat, three measurement sites are evenly selected along the longitudinal axis of the fruit, and the corresponding regional weight distribution in step S4 is: equal weight, that is, 33.3% for each point.

5. The method according to claim 1, characterized in that In step S2, if the surface of the sample to be measured is of shallow ridge and groove type, two measurement sites are located at the edges of the ridge and groove, and one measurement site is located at the ridge line. The corresponding regional weight distribution in step S4 is: 40%×2 for the ridge and groove area, and 20% for the ridge line.

6. The method according to claim 1, wherein In step S2, if the surface of the sample to be tested is of deep ridge / wrinkle type, 3 measurement sites are located at the bottom of the ridge and 2 measurement sites are located at the top of the wrinkle. The corresponding regional weight distribution in step S4 is: 20% × 3 for the ridge area and 20% × 2 for the top of the wrinkle.

7. The method according to claim 1, characterized in that In step S4, a laser displacement sensor conforming to JJF 1305 grade should be used to measure the groove depth C (mm) of the sample, and the groove depth compensation value is 0.5GU per 1mm depth.

8. The method according to claim 1, characterized in that In step S5, the classification criteria are as follows:

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