An online color difference measurement method, system, device and medium without standard samples

Abstract

The present invention discloses a method, system, device and medium for on-line color difference measurement without standard samples, which includes: continuously performing on-line measurement on an object to be measured by using a first color difference detection device; detecting a measured sample selected on the object to be measured by using a second color difference detection device, and calculating the difference between the color indexes of the measured sample and a standard sample; calculating virtual standard sample data according to the measured value of the measured sample and the difference; inputting the virtual standard sample data into the first color difference detection device for calibration, and continuing to perform on-line color difference measurement. It realizes accurate color difference data measurement without manual installation and replacement of standard samples for the on-line color difference meter system.

Description

Technical Field

[0001] The present invention relates to the technical field of color difference detection, and in particular to a method, system, device and medium for online color difference measurement without a standard sample. Background Art

[0002] In the industries of rolling materials printing and dyeing such as metallurgy, paper making, plastics, leather, cloth, etc., measuring the color difference between dyed rolling materials has quite important significance in industrial production. In particular, the color difference between the products of a manufacturer and a standard sample is a core index of quality control.

[0003] At present, in the prior art, the color difference detection link in the rolling materials printing and dyeing industry still relies on two forms: visual inspection by human eyes and offline measurement by using a professional colorimeter for local sampling in a contact manner.

[0004] First of all, for the visual inspection method, in addition to having a suitable environment and a light source that meets the requirements, it also requires that the rater has normal eyesight, and has undergone strict training and has rich color discrimination experience. In addition, the human eyes are prone to fatigue and are easily interfered by various factors, resulting in the detection results often not meeting the requirements. And color difference detection is a monotonous, heavy and repetitive labor for workers, and its labor intensity is also relatively large. More importantly, both the human eye detection and the offline detection by the color difference meter are affected by the experience, proficiency and some subjective factors of the inspectors, lacking consistency and reliability. Secondly, the method of local sampling is also the color difference standard release and arbitration method defined in various standards in the world at present, but its defect is that the degree of automation of offline local sampling is low, the detection speed is slow and the production cycle is increased. And the sampling representativeness is poor and cannot reflect the color difference index situation of all products. Finally, even if an online color difference meter is installed on the production line. However, due to the large aging drift problem existing in all non-contact color difference meters, manual installation and replacement of the standard sample are required, resulting in low production efficiency. Summary of the Invention

[0005] Embodiments of the present application provide a method, system, device and medium for online color difference measurement without a standard sample, which at least partially solve the technical problems of aging drift and manual replacement of the standard sample in color difference detection in the prior art, and achieve the technical effect that accurate color difference data can still be measured without manual installation and replacement of the standard sample for the online color difference meter system.

[0006] In a first aspect, to solve the above technical problems, embodiments of the present invention provide the following technical solutions:

[0007] A method for online color difference measurement without a standard sample, comprising:

[0008] Step S101, continuously performing online measurement on an object to be measured by using a first color difference detection device;

[0009] Step S102: Detect the measured sample selected on the object to be measured by using a second color difference detection device, and calculate the difference between the color indexes of the measured sample and the standard sample;

[0010] Step S103: Calculate virtual standard sample data based on the measured value of the measured sample and the above difference;

[0011] Step S104: Input the virtual standard sample data into a first color difference detection device for calibration, and continue with on-line color difference measurement.

[0012] Optionally, after participating in subsequent on-line color difference measurement, the above method further includes:

[0013] Step S105: Preset a calibration period; record the time point when the previous calibration was completed;

[0014] Step S106: When the detection time of the first color difference detection device reaches the calibration period, repeat Steps S102 to S104.

[0015] Optionally, Step S101 further includes:

[0016] Continuously acquire data of the object to be measured by using a first color difference detection device;

[0017] Based on the CIELab color space model, record the lightness index, chromaticity index, identity information, and position information corresponding to each measurement point.

[0018] Optionally, the step of detecting the measured sample selected on the object to be measured by using a second color difference detection device includes:

[0019] Regularly select measured samples on the object to be measured and record the corresponding position information, and perform detection and subsequent calculations by using a second color difference detection device.

[0020] Optionally, the step of calculating the difference between the color indexes of the measured sample and the standard sample includes:

[0021] Respectively calculate the differences between the lightness indexes, red-green chromaticity indexes, and yellow-blue chromaticity indexes of the measured sample and the standard sample to obtain the corresponding lightness difference, red-green chromaticity difference, and yellow-blue chromaticity difference.

[0022] Optionally, Step S103 further includes:

[0023] Retrieve the lightness indexes, red-green chromaticity indexes, and yellow-blue chromaticity indexes of multiple measured samples;

[0024] Calculate virtual standard sample data by using the backward inference method according to the corresponding lightness difference, red-green chromaticity difference, and yellow-blue chromaticity difference.

[0025] Optionally, after calculating the virtual standard sample data by using the back-calculation method, the method further includes:

[0026] The error range is preset, the virtual standard sample data that does not meet the error range is eliminated, the virtual standard sample data that meet the error range is averaged, and the final virtual standard sample data is obtained.

[0027] In a second aspect, a non-standard sample online color difference measurement system is provided, the system comprising:

[0028] A color difference data acquisition module, using the first color difference detection device to continuously perform online measurement on the object to be measured;

[0029] A difference calculation module is used to detect the sample selected from the object to be tested by using the second color difference detection device, and calculate the difference between the color index of the sample to be tested and the standard sample;

[0030] A virtual standard sample calculation module calculates virtual standard sample data according to the measured value of the sample under test and the difference value;

[0031] The calibration module inputs the virtual standard sample data into the first color difference detection device for calibration, and continues to perform online color difference measurement.

[0032] In a third aspect, an electronic device is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps corresponding to the method of the first aspect when executing the computer program.

[0033] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the steps corresponding to the above method in the first aspect are implemented.

[0034] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0035] The present invention adopts the method of continuously testing the object to be tested, and regularly collecting the detection points that meet the requirements as the sample to be tested; using the second color difference detection device, the lightness index, red-green color index and yellow-blue color index of the sample to be tested are respectively calculated with the data corresponding to the initial physical standard sample, so as to obtain the difference corresponding to each index. When the color difference detection device is subsequently calibrated, the reverse method is used to read the difference, and the corresponding data of the sample to be tested and the difference are used to calculate the difference, so as to obtain the data of the virtual standard sample, and then the standard sample value of the first color difference detection device 1 is used in the algorithm of the color difference detection device to perform online color difference measurement. In this way, accurate color difference data measurement can be performed without manual installation and replacement of the standard sample of the online colorimeter system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0037] Figure 1 It is a flowchart of a method for online color difference measurement without a standard sample provided by this application;

[0038] Figure 2 It is another flowchart of a method for online color difference measurement without a standard sample provided by this application;

[0039] Figure 3 It is a scenario where the method for online color difference measurement without a standard sample provided by this application is applied;

[0040] Figure 4 It is a schematic structural diagram of a system for online color difference measurement without a standard sample provided by this application;

[0041] Figure 5 It is a schematic structural diagram of an electronic device provided by this application.

[0042] Reference numerals: 1, the first color difference detection device; 2, the second color difference detection device; 3, communication optical fiber; 4, control cabinet; 5, object to be measured; 6, support frame. Detailed implementation manners

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0046] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the term "installation" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, rather than limitations of the technical solutions of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments may be combined with each other.

[0048] The embodiments of the present application provide a method, system, device and medium for online colorimetry without a standard sample, thereby improving the technical problems of time drift and manual replacement of standards in the prior art, and achieving the technical effect of accurately measuring colorimetry data without the need for manual installation and replacement of standards in the online colorimeter system.

[0049] The technical solution of the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0050] The present invention adopts the method of continuously testing the object to be tested 5 (i.e., the product produced online), and regularly collecting the detection points that meet the requirements as the sample to be tested; using the second color difference detection device 2, the lightness index, red-green color index and yellow-blue color index of the sample to be tested are respectively calculated with the data corresponding to the initial physical standard sample, so as to obtain the difference corresponding to each index. When the color difference detection device is subsequently calibrated, the reverse method is used to read the difference, and the corresponding data of the sample to be tested is used to calculate the difference with the difference, so as to obtain the data of the virtual table sample, and then the standard sample value of the first color difference detection device 1 is used in the algorithm of the color difference detection device to perform online color difference measurement. In this way, accurate color difference data measurement can be performed without manual installation and replacement of the standard sample of the online colorimeter system.

[0051] In the present application, the following examples are provided: Figure 1 A method for measuring color difference online without a standard sample is shown, the method comprising steps S101 to S103:

[0052] Step S101, using the first color difference detection device 1 to continuously perform online measurement on the object to be measured 5;

[0053] The sample is irradiated with an LED light source, and the detector in the color difference detection device receives the reflected light of the sample. The lens in the instrument collects the reflected light and directly projects it onto a diffraction grating. The grating splits the received reflected light into light of each component wavelength, and these scattered lights are measured by a silicon diode matrix and converted into the required color data. When detecting the object to be measured 5 (i.e., the dyed coil), its working state is to continuously move in a certain direction on a horizontal plane. Therefore, for the detection of the object to be measured 5, in this embodiment, color difference data is obtained by facing downwards directly above the object to be measured 5, and on-line measurement is continuously performed. Among them, the first color difference detection device 1 is an on-line color difference meter, and the second color difference detection device 2 is a desktop color difference meter.

[0054] Step S102: The measured sample selected on the above-mentioned object to be measured 5 is detected by the second color difference detection device 2, and the difference between the color indexes of the measured sample and the standard sample is calculated.

[0055] The basic principle of color difference detection is to compare the color data between the standard sample and the measured sample to detect the color difference of the object. During the detection process, the second color difference detection device 2 that is not on the production line is used for data testing, so that there is no need for manual installation and replacement of the standard sample for the on-line color difference meter system, and it will not interfere with the normal operation of the production line. And a defect-free measurement point in the on-line production product is selected as the measured sample for detection, the color difference of the measured sample is calculated, that is, the difference between the color indexes of the measured sample and the standard sample is calculated, and the position of the measured sample is recorded.

[0056] Step S103: Calculate the virtual standard sample data according to the above-mentioned measured value of the measured sample and the above-mentioned difference.

[0057] In this step, the data of the standard sample is mainly obtained by the backward deduction method. For example, if the original formula uses the measured value of the measured sample minus the standard sample to obtain the difference, then by backward deduction, the virtual standard sample is equal to the measured value of the measured sample minus the difference.

[0058] Step S104: Input the above-mentioned virtual standard sample data into the first color difference detection device for calibration, and continue to perform on-line color difference measurement.

[0059] The virtual standard sample data converted by the second color difference detection device is directly sent to the first color difference detection device as the detection data of the standard sample, enabling it to continue working. Therefore, there is no need to use the standard sample for multiple calibrations, and the first color difference detection device set on the production line can continuously perform on-line tests, improving production efficiency.

[0060] It should be noted that as Figure 3As shown in the figure, a scenario of the application of the online color difference measurement method without a standard sample is given in this embodiment. The support frame 6 bears the first color difference detection device 1 and detects the object to be measured 5 (i.e., the coil) moving downward. The arrow indicates the moving direction. The control cabinet 4 controls the first color difference detection device 1 and serves as a data processing medium to connect the second color difference detection device 2 through the communication optical fiber 3, thus completing the data intercommunication between the two color difference detection devices.

[0061] Further, after participating in the subsequent online color difference measurement, the above method further includes:

[0062] Step S105, preset a calibration period; record the time point when the previous calibration is completed;

[0063] Step S106, when the detection time of the first color difference detection device 1 reaches the calibration period, repeat steps S102 to S104.

[0064] It should be noted that the essence of the calibration period is to achieve calibration automation and at the same time complete a higher degree of automatic calibration without a standard sample in online color difference measurement. The setting of the calibration period is determined based on the historical data or experimental data to statistically calculate the aging drift duration of the color difference detection device during the production process. That is, its control program is set so that when the measurement time of the first color difference detection device 1 meets this period, it means that the first color difference meter is about to have aging drift, so steps S102 to S104 are repeated for calibration.

[0065] It should also be noted that since the production line environments in different coils or different production workshops are different, the specific value of the calibration period can be adjusted according to user requirements and the aging drift situation in the corresponding environment.

[0066] Further, step S101 above further includes:

[0067] Use the first color difference detection device 1 to continuously obtain data for the object to be measured 5;

[0068] Based on the CIELab color space model, record the lightness index, chromaticity index, identity information, and position information corresponding to each measurement point.

[0069] It should be noted that for the calculation of color difference, a color space model is generally used for quantification. There are mainly color space models such as RGB, CMYK, and CIELab, etc. This embodiment preferably uses the CIELab color space model and describes it as an example. The identity information is the coil number of the coil.

[0070] It should also be noted that the CIELab color space model defines the CIE color space using the lightness index L (luminance axis), the chromaticity index a (red-green axis), and the chromaticity index b (yellow-blue axis). Among them, the lightness index L represents black and white, 0 is black, 100 is white, and (0, 100) is gray. In the chromaticity index a (red-green axis), positive values are red and negative values are green. In the chromaticity index b (yellow-blue axis), positive values are yellow and negative values are blue.

[0071] Furthermore, the detection step of the measured sample selected on the object to be measured 5 using the second color difference detection device 2 further includes:

[0072] Regularly select measured samples on the object to be measured 5 above and record the corresponding position information, and use the second color difference detection device 2 for detection and subsequent calculations.

[0073] It should be noted that regularly obtaining samples is for continuous calculations to continuously calculate the subsequent virtual standard sample data. At the same time, recording the position information can directly locate the physical position. The specific positioning method is that since the moving direction of the coil is fixed, the moving length of the coil is used for position recording as the longitudinal position.

[0074] Furthermore, the step of calculating the difference in color indexes between the measured sample and the standard sample includes:

[0075] Find the differences between the lightness index, red-green chromaticity index, and yellow-blue chromaticity index of the measured sample and the standard sample above respectively to obtain the corresponding lightness difference, red-green chromaticity difference, and yellow-blue chromaticity difference.

[0076] The specific calculation is as follows:

[0077] Define the lightness index of the measured sample as L, the red-green chromaticity index as a, the yellow-blue chromaticity index as b, the coil number as K, and the corresponding longitudinal position value as s; define the lightness index of the standard sample as , the red-green chromaticity index as , the yellow-blue chromaticity index as .

[0078]

[0079]

[0080]

[0081]

[0082] Among them 、 、 They are the differences corresponding to the lightness index, red-green chromaticity index, and yellow-blue chromaticity index respectively. is the total color difference, that is, the average color difference.

[0083] Furthermore, the above step S103 further includes:

[0084] Retrieve the lightness index, red-green chromaticity index, and yellow-blue chromaticity index of multiple measured samples;

[0085] According to the above-mentioned lightness difference, red-green chromaticity difference, and yellow-blue chromaticity difference, use the backward deduction method to calculate the virtual standard sample data.

[0086] It should be noted that the backward deduction method is reverse calculation, and its calculation process is as follows:

[0087] Define the lightness index of the virtual standard sample as , the red-green chromaticity index as , and the yellow-blue chromaticity index as ;

[0088]

[0089]

[0090]

[0091] Bring the , , of the virtual standard sample into the input first color difference detection device for calibration, and continue with on-line color difference measurement.

[0092] Furthermore, after calculating the virtual standard sample data using the backward deduction method, it further includes:

[0093] Preset an error range, eliminate the virtual standard sample data that does not meet the error range, and average the virtual standard sample data within the error range to obtain the final virtual standard sample data.

[0094] It should be noted that since the environment in the production workshop is relatively harsh, it is very likely that external factors will interfere during the measurement of samples, such as dust, etc. Therefore, an error range is set, and the data with a color difference exceeding the range is eliminated to avoid the occurrence of incorrect data. In addition, the method of taking the average value is used to improve the accuracy of the standard sample.

[0095] Based on the same inventive concept, an embodiment of the present application provides a calibration-free on-line color difference measurement system, as Figure 4 shown, including:

[0096] A color difference data acquisition module 201 that continuously performs on-line measurement on the object to be measured 5 using the first color difference detection device 1;

[0097] The difference calculation module 202 detects the measured sample selected on the object 5 to be measured by using the second color difference detection device 2, and calculates the difference between the color indexes of the measured sample and the standard sample;

[0098] The virtual standard sample calculation module 203 calculates virtual standard sample data according to the measured value of the measured sample and the difference;

[0099] The calibration module 204 inputs the virtual standard sample data into the first color difference detection device for calibration, and continues to perform on-line color difference measurement.

[0100] Based on the same inventive concept, as Figure 5 shown, this embodiment provides an electronic device, and the electronic device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, an on-line color difference measurement method without a standard sample is implemented.

[0101] Based on the same inventive concept, this embodiment provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, an on-line color difference measurement method without a standard sample is implemented.

[0102] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0103] In summary, the present invention provides a method, system, device and medium for on-line color difference measurement without standard sample. It continuously tests the object to be measured and regularly collects detection points that meet the requirements as the measured samples. The second color difference detection device is used to calculate the differences between the lightness index, red-green chromaticity index and yellow-blue chromaticity index of the measured samples and the corresponding data of the initial physical standard sample, so as to obtain the differences corresponding to each index. When the subsequent color difference detection device performs calibration, the inverse deduction method is used to read the difference, and the difference is subtracted from the data of the corresponding measured sample to obtain the data of the virtual sample, which is then used as the standard sample value in the algorithm of the first color difference detection device 1 for on-line color difference measurement. Thus, it is possible to perform accurate color difference data measurement without manually installing and replacing the standard sample in the on-line color difference meter system. At the same time, the method of averaging multiple data and the method of regular calibration are adopted to further ensure the detection accuracy.

[0104] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0105] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. An on-line color difference measurement method without standard sample, characterized in that, The method includes: Step S101, continuously performing on-line measurement on the object to be measured by using a first color difference detection device; Step S102, detecting the measured sample selected on the object to be measured by using a second color difference detection device, and calculating the difference between the color indexes of the measured sample and the standard sample; the second color difference detection device is not on the production line; Step S103, calculating virtual standard sample data according to the measured value of the measured sample and the difference value; Step S104, inputting the virtual standard sample data into the first color difference detection device for calibration, and continuing to perform on-line color difference measurement; The step of detecting the measured sample selected on the object to be measured by using a second color difference detection device further includes: Regularly selecting measured samples on the object to be measured and recording the corresponding position information, and performing detection and subsequent calculation by using a second color difference detection device; The step of calculating the difference between the color indexes of the measured sample and the standard sample includes: Respectively calculating the difference between the lightness indexes, red-green chromaticity indexes, and yellow-blue chromaticity indexes of the measured sample and the standard sample to obtain the corresponding lightness difference value, red-green chromaticity difference value, and yellow-blue chromaticity difference value; Step S103 further includes: Retrieving the lightness indexes, red-green chromaticity indexes, and yellow-blue chromaticity indexes of multiple measured samples; Calculating the virtual standard sample data by using the backward inference method according to the corresponding lightness difference value, red-green chromaticity difference value, and yellow-blue chromaticity difference value.

2. The method according to claim 1, characterized in that, After participating in the subsequent on-line color difference measurement, the method further includes: Step S105, presetting a calibration period; recording the time point when the previous calibration is completed; Step S106, when the detection time of the first color difference detection device reaches the calibration period, repeating steps S102 to S104.

3. The method according to claim 1, characterized in that, Step S101 further includes: Continuously acquiring data of the object to be measured by using a first color difference detection device; Based on the CIELab color space model, recording the lightness index, chromaticity index, identity information, and position information corresponding to each measurement point.

4. The method according to claim 1, characterized in that, After calculating the virtual standard sample data by using the backward inference method, it further includes: Presetting an error range, eliminating the virtual standard sample data that does not meet the error range, and averaging the virtual standard sample data that meets the error range to obtain the final virtual standard sample data.

5. An on-line color difference measurement system without standard sample, the system is used to implement the method steps described in any one of claims 1 to 4, characterized in that, It includes: A color difference data acquisition module, which continuously performs on-line measurement on the object to be measured by using a first color difference detection device; A difference calculation module, which detects the measured sample selected on the object to be measured by using a second color difference detection device, and calculates the difference between the color indexes of the measured sample and the standard sample; The second color difference detection device is not on the production line; A virtual standard sample calculation module, which calculates virtual standard sample data according to the measured value of the measured sample and the difference value; A calibration module, which inputs the virtual standard sample data into the first color difference detection device for calibration, and continues to perform on-line color difference measurement.

6. An electronic device, characterized in that, The electronic device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the method steps described in any one of claims 1 to 4.

7. A computer-readable storage medium, on which a computer program is stored, characterized in that, When the program is executed by the processor, it implements the steps corresponding to the method described in any one of claims 1 to 4.

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