Method for determining a parameter related to the coloring of a body

Abstract

A method for determining a parameter related to coloration of a body region of an individual. The invention relates to a method for determining a parameter relating to the coloration of a body region of an individual, comprising the steps of:-selecting a sample (10) for the individual from a set of samples (10), each sample (10) in the set being a sample representing a body region and having a different reference color than the other samples (10); -acquiring an image, i.e., a so-called initial image, by means of a sensor and imaging the selected sample (10) and a corresponding body region of the individual; -processing the initial image by a calculator to obtain parameters relating to the coloration of the body region of the individual.

Description

Technical Field

[0001] The invention relates to a method for determining parameters related to the coloration of a body area of ​​an individual, such as hair, skin or nails, and to an associated determination device. Background Art

[0002] The cosmetics industry aims to improve the experience of its consumers. In particular, there is a strong trend towards offering products that are increasingly adapted to the specific needs and characteristics of the user. This trend is generally referred to as "customization".

[0003] Customized cosmetic products and services can involve any part of the human body, but are particularly important for exposed parts of the body, such as the face (make-up or skin care products, especially foundation) and hair (such as hair care or hair coloring products).

[0004] Thus, it is known that one or more characteristics of a user's skin can be used to recommend a suitable foundation (e.g. of It is also known to provide customized hair care products, the ingredients of which are determined according to the different properties of the user's hair (see, for example, document EP 0 443 741, as well as documents WO 2004 / 002300 A2 and US Pat. No. 9,316,580 B).

[0005] The concept of customization goes beyond the simple fact of offering a more or less wide range of products, each corresponding to a category of users. The difficulty often lies in how to recommend the most suitable product to the user based on the specific characteristics of the individual.

[0006] As described in the literature mentioned above, the concept of customization generally includes a first analysis step, which aims to obtain one or more data specific to the relevant user, and then determine from this data a suitable care method and / or one or more suitable products intended to be applied to the relevant body parts of the user.

[0007] Until recently, the analysis step was usually performed manually or visually by an expert, such as a hairdresser or beauty consultant. In particular, this method requires the user to fill out a questionnaire, the answers of which can be used to recommend the most suitable products for them (see in particular document US2014 / 0216492 A). Obviously, such a technique has a high degree of uncertainty and lacks precision.

[0008] To improve the relevance and reliability of product recommendations, one or more steps may be performed using tools or devices, and may even be automated.

[0009] Thus, all or part of the initial characteristics specific to the user can be obtained by objective measurements obtained using appropriate measuring devices. An example of such a device is the CAPSURE device sold by the company X-RITE, which is designed to return a color code representing the color of the material measured (e.g. the user's skin) (see in particular document US 2010 / 0328667 A, which, however, does not explicitly address skin or keratin surfaces).

[0010] In addition, in order to help users choose products, augmented reality software is also known, which can virtually try out makeup products. Typically, such software enables the calculation and generation of corresponding images from a digital image of the user, which shows the makeup effect that may be obtained when applying the product under consideration. It is known that such a system provides the function of virtually trying out foundation, lipstick or hair dyeing in the same way as used for clothing or glasses. Thanks to such a system, users can easily evaluate the makeup effects of multiple products directly and immediately without purchasing, applying makeup and removing makeup. Examples of methods for virtual trial ("virtual try-on") makeup products are described, for example, in documents US20200160153A1 and US9449412B1 and applications FR21 / 06030, FR21 / 11155 and FR21 / 11164 under the name of the applicant and not yet published.

[0011] However, these tools can also be improved to provide users with a presentation that is closest to the desired presentation.

[0012] Therefore, there is a need to facilitate and improve the accuracy of determining parameters related to the coloration of an individual's body region, such as hair, skin or nails. Summary of the invention

[0013] To this end, the object of the present description is a method for determining parameters related to the coloration of a body area of ​​an individual, such as hair, skin or nails, comprising the following steps: - selecting a sample for the individual from a set of samples, each sample in said set being a sample representing a body region and having a reference color different from the other samples, each sample having an identifier visible on said sample, said identifier for each sample being associated with colorimetric data representing the reference color of said sample, so-called sample reference data, said sample reference data for each identifier being stored in a database, - acquisition of images, so-called initial images, by means of sensors, which images the selected sample and the corresponding body region of the individual, and - processing said initial image by means of a calculator so that: o obtaining the sample reference data of the sample imaged on the initial image based on the identifier of the sample and the database accessible by the computer, and o obtaining colorimetric data representing the actual color of the sample on the initial image, so-called sample actual data, The sample reference data and the sample actual data form parameters related to the coloration of the body area of ​​the individual.

[0014] According to a particular embodiment, the method comprises one or more of the following features considered alone or in any technically feasible combination: The method comprises the following steps: the calculator determines the influence of the environment on the colorimetric rendering of the body area of ​​the individual by comparing the sample reference data with the sample actual data. - the method comprises a step of virtually trying out the selected sample, the step comprising: o the calculator modifies the initial image according to the actual data of the sample, so that the color of the body area of ​​the individual on the initial image is replaced by the actual color of the sample on the initial image, and the modified initial image forms a presentation effect image, and o displaying the presentation effect image on a display; The method comprises the following steps: after receiving a command to verify the rendered effect image, the calculator determines the coloring of the body area of ​​the individual according to the initial image, the sample reference data and the sample actual data. -The step of determining the coloring includes determining colorimetric data representing the actual color of the body area of ​​the individual on the initial image, which colorimetric data is called individual actual data, and determining the coloring of the body area of ​​the individual based on the individual actual data, the sample reference data and the sample actual data. - The step of determining the coloring also includes: o determining the colorimetric difference between the sample reference data and the sample actual data, o determining colorimetric data representing a reference color of the body area of ​​the individual, so-called individual reference data, based on the individual actual data and the differences, and o Determining a coloration of the body region of the individual based on the individual reference data and the sample reference data. - the processing step comprises: highlighting the sample on the initial image and determining actual data of the sample on a portion of the initial image featuring the sample. - said highlighting is performed by segmentation or, after identifying said identifier on said initial image, by extracting a region around said identifier of said sample on said initial image. - the sample is selected from the list consisting of: photographs, sticky notes, fabrics, figurines, miniature products, and real or fake samples of parts of the human body, such as hair strands, simulated skin samples, false eyelashes, false eyebrows, or false nails; - the identifier is selected from: a number, a series of alphanumeric characters, a barcode, a radio identification tag, a near field communication tag and a tag enabling visual identification.

[0015] The present description also relates to a device for determining parameters related to the coloration of a body region of an individual, such as hair, skin or nails, after selecting a sample for the individual from a set of samples, each sample in the set being a sample representing a body region and having a reference color different from the other samples, each sample having an identifier visible on the sample, the identifier of each sample being associated with colorimetric data representing the reference color of the sample, so-called sample reference data, the sample reference data for each identifier being stored in a database, the device comprising: a sensor capable of acquiring an image, a so-called initial image, which images the selected sample and the corresponding body region of the individual, and a computer, the computer having access to the database, the computer being configured to process the initial image so that: o obtaining the sample reference data of the sample imaged on the initial image based on the identifier of the sample and the database accessible by the computer, and o obtaining colorimetric data representing the actual color of the sample on the initial image, so-called sample actual data, o The sample reference data and the sample actual data form parameters related to the coloration of the body area of ​​the individual. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other characteristics and advantages of the invention will emerge on reading the following description of embodiments of the invention provided purely by way of example, and with reference to the accompanying drawings, in which:

[0017] [ Figure 1 ], Figure 1 is a schematic diagram of an example of a sample set,

[0018] [ Figure 2 ], Figure 2is a schematic diagram of an example of an apparatus for determining a parameter related to coloration of a body region of an individual,

[0019] [ Figure 3 ], Figure 3 is a flow chart of an example of an implementation of a method for determining a parameter related to coloration of a body region of an individual, and

[0020] [ Figure 4 ], Figure 4 yes Figure 3 A schematic diagram of the implementation of some steps of the method. DETAILED DESCRIPTION

[0021] In the following description, a body region refers to, for example, the hair, skin, or one or more nails of an individual. A specific example of a body region is hair, in particular hair ( Figure 1 and Figure 4 ). However, the present description is applicable to any other body region type.

[0022] In the remainder of the description, the term "hairs" refers to all types of hair on an individual, regardless of their location on the individual's body surface. Hair includes the individual's hair system. Head hair, eyelashes, and eyebrows are examples of hair.

[0023] In general, the term "cosmetic product" refers to any product as defined in Regulation (EC) No 1223 / 2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products. More specifically, color cosmetic products are intended to cover the surface of the body in order to modify its sensory perception of color and / or texture. Specifically, the concept of cosmetic products covers any substance or mixture intended to come into contact with the surface parts of the human body (epidermis, hair follicles and capillary system, nails, lips and external genitalia) or with the teeth and oral mucosa, where the sole or main purpose is to cleanse, scent, modify the appearance, protect, maintain good condition or eliminate body odor.

[0024] For example, cosmetics are dye formulations, also called "dyes", or products in paste, liquid, etc., that are intended to come into contact with areas of the body to color them. This coloration can be permanent or temporary.

[0025] The term "color" in cosmetics refers to the color or the appearance of color that is visible after the cosmetic is applied to a body area of ​​a reference individual or a model of a body area. For example, in the case of hair, once the cosmetic is applied to the hair of a given individual, the color may appear different than the appearance obtained for the reference individual or the hair model, given that the nature and lifespan of hair vary from individual to individual.

[0026] Figure 1 An example of a set of 10 samples is shown.

[0027] The set of samples 10 comprises at least two samples 10, advantageously more than two samples 10. A sample 10 is an object that can be manipulated by an individual.

[0028] Each sample 10 represents a body region. A body region is, for example, hair, skin or one or more nails of an individual.

[0029] Advantageously, the sample 10 is selected from a list comprising: photographs, sticky notes, fabrics, figurines, miniature products and real or fake samples of parts of the human body, such as hair strands (real or fake), simulated skin samples, false eyelashes, false eyebrows or false nails.

[0030] exist Figure 1 In the particular example shown, the sample collection is a collection of hair, in particular hair bundles forming a hair color card.

[0031] The reference color of each sample 10 is different from the other samples 10. A "reference color" is to be understood as a predefined color of the sample 10, which has been obtained, for example, by placing the object in a predefined environment. For example, the reference color has been measured in such an environment by a sensor, such as a spectrocolorimeter.

[0032] Advantageously, each specimen 10 is detachably or non-detachably attached to the same support.Preferably, the support is carryable or manipulable by an individual.

[0033] For example, the support is a catalog. A "catalog" is to be understood as a finished product in which the sample 10 is recorded. In the case where the sample 10 is a hair bundle, such a catalog thus forms a hair color card.

[0034] Each sample 10 is associated with an identifier 10A. An “identifier” should be understood as data capable of identifying a sample 10 in a set of samples 10.

[0035] The identifier 10A is visible on the sample 10. For example, the identifier 10A is marked in the sample 10 or is an integral part of the sample 10.

[0036] Advantageously, the identifier 10A of each sample 10 is unique.

[0037] For example, the identifier 10A is selected from a list comprising: a number, a series of alphanumeric characters, a barcode, a radio identification tag (RFID chip), a near field communication tag (NFC chip) and a tag enabling visual recognition. For example, the barcode is a QR (short for Quick Response) code.

[0038] The identifier 10A of each sample 10 is associated with colorimetric data representing a reference color of the sample 10 (the so-called sample reference data D ref_E ). For example, sample reference data D ref_E It has been obtained by measurements performed with a spectrocolorimeter.

[0039] Sample reference data D for each identifier 10A ref_E is stored in the database 11. Therefore, given the known identifier 10A, the sample reference data D ref_E For example, it is obtained through a lookup table stored in the database 11 .

[0040] Figure 2 An example of an apparatus 12 for determining a parameter related to the coloration of a body region of an individual is shown.

[0041] The device 12 includes a sensor 13 and a calculator 14 .

[0042] The sensor 13 is capable of acquiring images of the environment.

[0043] For example, the sensor 13 is a video camera or a still camera.

[0044] The calculator 14 can interact with a computer program product 18. The interaction of the computer program product 18 with the calculator 14 can implement the steps of a method for determining a parameter related to the coloration of a body region of an individual.

[0045] For example, the calculator 14 is a computer. More generally, the calculator 14 is an electronic calculator that can manipulate data represented as electronic or physical quantities in registers and / or memories of the calculator 14 and / or that can convert data represented as electronic or physical quantities in registers and / or memories of the calculator 14 into other similar data corresponding to physical data in memories, registers or other types of display devices, transmission devices or storage devices.

[0046] The computer 14 includes a processor 20, which includes a processing unit 22, a memory 24, and an information medium reader 26. Figure 2 In the example shown, the calculator 14 also includes a human-machine interface 27 including, for example, a keyboard 28 and / or a touch-sensitive interface and a display 30 .

[0047] The computer program 18 comprises a readable information support. The readable information medium is a medium readable by the computer 14, typically by the processing unit 22 of the computer 14. The readable information medium is a medium suitable for storing electronic instructions and capable of being coupled to a bus of a computer system.

[0048] For example, the readable information medium is a USB flash drive, a floppy disk or diskette ("floppy disk"), an optical disk, a CD-ROM, a magneto-optical disk, a ROM memory, a RAM memory, an EPROM memory, an EEPROM memory, a magnetic card or an optical card.

[0049] The computer program containing program instructions is stored on a readable information support.The computer program can be loaded onto the data processing unit 22 and is adapted to cause implementation of at least one of the steps of the method for determining parameters relating to the coloration of a body region of an individual.

[0050] The determination device 12 has access to the database 11, the identifier 10A and the corresponding sample reference data D ref_E All are recorded in the database 11.

[0051] For example, the database 11 is stored on a remote server of the determination device 12, and then the database 11 is accessed according to a wireless transmission protocol or according to a cellular telecommunication network protocol. For example, the wireless transmission protocol is established according to the standards of the group IEEE 802.11 (Wi-Fi) or the group IEEE 802.15 (Bluetooth). For example, the cellular telecommunication network protocol is established according to the GSM (Global System for Mobile Communications) standard or according to the UMTS (Universal Mobile Telecommunications System), 4G or 5G technology.

[0052] Alternatively, the database 11 is stored in the memory 24 of the calculator 14, which enables the calculator 14 to directly access the database 11 without any wireless transmission protocol or cellular telecommunication network.

[0053] In an example of an implementation, the determining device 12 is a connected object. For example, the determining device 12 is a smartphone, a tablet, a connected mirror, or any other connected object provided with an image acquisition sensor. In this case, the sensor 13 and the calculator 14 are components of the smartphone, the tablet, the connected mirror, or components of a more general connected object.

[0054] Reference now Figure 3 Flowchart and Figure 4 An example of an implementation of a method for determining parameters related to the coloring of a body area, in particular the hair, such as hair, of an individual is described with reference to an illustrative diagram.

[0055] The determination method comprises step 100 of selecting a sample 10 for an individual from a set of samples 10 .

[0056] "For an individual" is to be understood as performing the selection while taking into account the individual's wishes and / or needs. Therefore, the selection will a priori vary from one individual to another. Therefore, the selection is specific to a given individual. In particular, this selection is made possible by the unique reference colors of the different samples 10 of the collection.

[0057] The selection may be performed by the individual themselves or by a third party taking into account the individual's wishes and / or needs. For example, the third party is a beauty professional such as a hairdresser, stylist, esthetician or makeup artist.

[0058] For example, in the case of dyeing hair (or hair more generally), the selection comprises selecting a sample 10 corresponding to the target dye color. Alternatively, the selection comprises selecting a sample 10 corresponding to the natural color of the individual's hair or the current color of the individual's hair (particularly when the hair has been dyed).

[0059] In another example, when the considered body area is the skin, such as the skin of the face, the selecting comprises selecting a sample 10 corresponding to the natural color of the skin or to a target dye color of the skin (eg for foundation).

[0060] Figure 4 The example of FIG. 1 shows that sample 10 in the upper left corner is selected.

[0061] The determination method then comprises a step 110 of acquiring an image, a so-called initial image IM, by means of the sensor 13 of the determination device 12, said initial image imaging the body region of the individual and the selected sample 10. In particular, the identifier 10A of the selected sample 10 is visible in the initial image M.

[0062] For example, during this acquisition step 110, the sample 10 is positioned next to a body region (eg hair) of the individual. Alternatively, the sample 10 is superimposed on the body region of the individual.

[0063] The initial image IM obtained is Figure 4 is shown in the example.

[0064] The determination method comprises a step 120 of processing the initial image IM. The processing step 120 is implemented by the interaction between the computer 14 and the computer program product 18, that is, by a computer.

[0065] The processing step 120 can obtain from the initial image IM: - Sample reference data D of the sample 10 imaged on the initial image IM ref E ,as well as - Colorimetric data representing the actual color of the sample 10 on the initial image IM, the so-called sample actual data Dr_E In particular, the actual color takes into account the environmental conditions (brightness, lighting, ...) in which the individual is located.

[0066] It can be understood that the sample reference data D ref_E And the sample actual data D r_E Each of these data may actually correspond to a data set. For example, in the space CIE L*a*b, each of these data corresponds to data related to clarity L, data related to parameter a*, and data related to parameter b*.

[0067] In an example of implementation, based on the identifier 10A of the sample 10 and the database 11 accessible by the computer 14, the sample reference data D is obtained. ref_E .

[0068] In an example of implementation, the processing step 120 includes highlighting the sample 10 on the initial image IM and determining the sample actual data D on the portion of the initial image IM characterized by the sample 10. r_E .

[0069] For example, highlighting is performed by segmentation, which can extract the sample 10 from the rest of the environment on the initial image IM. In another example, after recognizing the identifier 10A on the initial image IM, highlighting is performed by extracting a region around the identifier 10A of the sample 10 on the initial image IM.

[0070] Then, the sample reference data D is determined according to the colorimetric data of the pixels corresponding to the found area. ref_E .

[0071] In another example, the sample reference data D ref_E The method for obtaining is similar to the method described in US application US 2020 / 342630A.

[0072] Sample reference data D ref_E And the sample actual data D r_E Parameters are formed relating to the coloration of a body region of an individual. Such parameters can therefore be used to determine a coloration that is appropriate for the individual and that takes into account differences in rendering effects due to the environment.

[0073] Optionally, the determination method comprises step 130: determining the influence of the environment on the colorimetric rendering effect of the body area of ​​the individual. The determination step 130 is implemented by the interaction between the calculator 14 and the computer program product 18, that is, by a computer.

[0074] By comparing the sample reference data D ref_E The actual sample data D r_E To perform the determination step 130.

[0075] For example, the comparison enables obtaining a colorimetric difference parameter. In particular, the colorimetric difference parameter depends on at least one quantity representing a colorimetric space. For example, in the space CIE L*a*b, the deviation parameter depends on at least one of the lightness L, the parameter a* and the parameter b*.

[0076] For example, the colorimetric difference parameter is obtained by the following formula: in: ·ΔE represents sample reference data D ref_E The actual sample data D r_E The colorimetric difference parameter between ΔL * is the sample reference data D in the space CIE L*a*b ref_E The clarity and sample actual data D r_E The difference between the clarity, ·Δa * is the sample reference data D in the space CIE L*a*b ref_E The parameter a* and the actual sample data D r_E The difference between the parameters a* and ·Δb * is the sample reference data D in the space CIE L*a*b ref_E The parameter b* and the actual sample data D r_E The difference between the parameters b*.

[0077] Preferably, the determination step includes a step 140 of virtually trying out ("try-on") the selected sample 10. The virtual try-on step 140 is implemented by the interaction between the calculator 14 and the computer program product 18, ie, by a computer.

[0078] The virtual trial step 140 includes: r_E The initial image IM is modified so that the color of the body area of ​​the individual on the initial image IM is replaced by the actual color of the sample 10 on the initial image IM. The modified initial image IM forms a rendering effect image IM R . Rendering effect image IM R Examples of Figure 4 shown.

[0079] Possibly, during this step 140 , a presentation effect model as described in documents US 20200160153 A or US 9449412 B is applied, enabling an improved virtual try-on.

[0080] The virtual trial step 140 also includes displaying the rendering effect image IM on the display. R The display is, for example, the display 30 of the calculator 14 .

[0081] Preferably, the determination method comprises step 150: upon receiving the verification presentation effect image IM R After the command is given, the coloration associated with the body region of the individual is determined. The determination step 150 is implemented by the interaction between the calculator 14 and the computer program product 18, that is, by a computer.

[0082] For example, a verification command is sent by the individual or another person (barber) to the calculator 14 via the human-machine interface of the calculator 14. This command indicates that the colorimetric rendering of the selected sample 10 is suitable for the individual and can be used as a basis for determining the coloration.

[0083] According to the initial image IM, sample reference data D ref_E And the sample actual data D r_E Determine the coloring.

[0084] Specifically, in an example of an implementation, the determination step 150 comprises determining colorimetric data representing the actual color of the body region of the individual on the initial image IM, namely the so-called individual actual data D r_I For example, individual actual data D r_I With the sample actual data D r_E The colorimetric data of the pixels are obtained in the same manner (highlighting the pixels corresponding to the body area of ​​the individual on the initial image IM and extracting the colorimetric data of the pixels).

[0085] Afterwards, according to the individual actual data D r_I , sample reference data D ref_E And the sample actual data D r_E Determine the coloration associated with the body region of the individual. Specifically, in the example of implementation, the determination step 150 also includes determining the coloration associated with the body region of the individual according to the sample reference data D ref_E And the sample actual data D r_E The colorimetric difference is determined. For example, the colorimetric difference is the difference determined during the determining step 130 .

[0086] Then, the determination step 150 includes determining the individual actual data D r_I The colorimetric data representing the reference color of the body area of ​​the individual, namely the so-called individual reference data D ref_I . Individual reference data D ref_I is the color of the body area of ​​the individual, which has been adjusted for the environmental conditions (brightness, lighting, etc.) of the individual and based on the sample reference data D ref_E Compensation was performed as a reference.

[0087] Afterwards, according to the individual reference data D ref_I and sample reference data D ref_E To determine the coloration of individual body regions.

[0088] For example, the coloration is determined according to the method described in application WO 2020 / 193654A.

[0089] Thus, the present method can facilitate obtaining parameters useful for determining the appropriate coloration of an individual's body region (eg, hair, such as head hair).

[0090] In particular, the initial image IM enables to obtain a reference color of the sample and the actual color of the sample (depending on the rendering in the environment). These data also enable to infer information about the rendering conditions (lighting, brightness) and, therefore, to obtain a higher accuracy in the colorimetric rendering determined later. In particular, these data can then be used to feed a virtual try-on engine, or to determine the color of a body area of ​​an individual or the desired coloration of a body area of ​​an individual.

[0091] Furthermore, the implementation of this method is very simple since the data are obtained through image acquisition.

[0092] Therefore, this method can facilitate and improve accuracy when determining the parameters of coloration of an individual's body area, especially when selecting hair coloring products, and the effects of applying this method are almost immediate and difficult to change instantly.

[0093] Those skilled in the art will understand that, as long as they are technically compatible, the embodiments described above may be combined to form new embodiments.

Claims

1. A method for determining a parameter related to the coloration of a body area of ​​an individual, such as hair, skin or nails, the method comprising the following steps: a. Selecting a sample (10) for an individual from a set of samples (10), each sample (10) in the set being a sample representing a body region and having a reference color different from the other samples (10), each sample (10) having an identifier (10A) visible on the sample (10), the identifier (10A) of each sample (10) being associated with colorimetric data representing the reference color of the sample (10), so-called sample reference data (D ref_E ) is associated with the sample reference data (D ref_E ) is stored in the database (11), b. Acquiring an image, a so-called initial image (IM), by means of a sensor (13), which images the selected sample (10) and the corresponding body region of the individual, and c. Processing the initial image (IM) by a calculator (14) so ​​that: i. Based on the identifier (10A) of the sample (10) and the calculator (14) The database (11) accessed to obtain the sample reference data (D) of the sample (10) imaged on the initial image (IM) ref_E ),as well as ii. obtaining colorimetric data representing the actual color of the sample (10) on the initial image (IM), the so-called sample actual data (D r_E ), The sample reference data (D ref_E ) and the sample actual data (D r_E ) forms parameters related to the coloration of said body area of ​​said individual.

2. The method according to claim 1, wherein: The method comprises the following steps: the calculator (14) compares the sample reference data (D ref_E ) and the actual sample data (D r_E ) to determine the effect of the environment on the colorimetric rendering of the body area of ​​the individual.

3. The method according to claim 1 or 2, wherein: The method comprises the step of virtually trying out the selected sample (10), the step comprising: a. The calculator (14) is based on the sample actual data (D r_E ) modifies the initial image (IM) so that the color of the body area of ​​the individual on the initial image (IM) is replaced by the actual color of the sample on the initial image (IM), and the modified initial image (IM) forms a rendering effect image (IM R ),as well as b. Displaying the rendering effect image (IM) on the display (30) R ).

4. The method according to claim 3, wherein: The method comprises the following steps: upon receiving a verification image (IM R ), the calculator (14) generates a signal according to the initial image (IM), the sample reference data (D ref_E ) and the sample actual data (D r_E ) to determine the coloring of the body region of the individual.

5. The method according to claim 4, wherein: The step of determining the coloration comprises determining colorimetric data representing the actual color of the body region of the individual on the initial image (IM), the colorimetric data being referred to as individual actual data (D r_I ), according to the individual actual data (D r_I ), the sample reference data (D ref_E ) and the sample actual data (D r_E ) to determine the coloring of the body region of the individual.

6. The method according to claim 5, wherein: The step of determining the coloring also includes: a. Determine the sample reference data (D ref_E ) and the actual sample data (D r_E ), and b. According to the individual actual data (D r_I ) and the difference, determining colorimetric data representing a reference color of the body area of ​​the individual, the so-called individual reference data (D ref_I ), According to the individual reference data (D ref_I ) and the sample reference data (D ref_E ) to determine the coloring of the body region of the individual.

7. The method according to any one of claims 1 to 6, wherein: The processing step comprises: highlighting the sample (10) on the initial image (IM), and determining the sample actual data (D) on the portion of the initial image (IM) characterized by the sample (10). r_E ).

8. The method according to claim 7, wherein: The highlighting is performed by segmentation or, after identifying the identifier (10A) on the initial image (IM), by extracting a region around the identifier (10A) of the sample (10) on the initial image (IM).

9. The method according to any one of claims 1 to 8, wherein: The sample (10) is selected from the list consisting of: photographs, sticky notes, fabrics, figurines, miniature products, and real or fake samples of parts of the human body, such as hair strands, simulated skin samples, false eyelashes, false eyebrows, or false nails.

10. The method according to any one of claims 1 to 9, wherein: The identifier (10A) is selected from the group consisting of: a number, a series of alphanumeric characters, a bar code, a radio identification tag, a near field communication tag, and a tag enabling visual identification.

11. A device (12) for determining parameters relating to the coloration of a body region of an individual, such as hair, skin or nails, after selecting a sample (10) for the individual from a set of samples (10), each sample (10) in the set being a sample representing a body region and having a reference color different from the other samples (10), each sample (10) having an identifier (10A) visible on the sample (10), the identifier (10A) of each sample (10) being associated with colorimetric data representing the reference color of the sample (10), so-called sample reference data (D). ref_E ) is associated with the sample reference data (D ref_E ) is stored in a database (11), the device (12) comprising: a. a sensor (13) capable of acquiring an image, a so-called initial image (IM), which images the selected sample (10) and the corresponding body region of the individual, and b. a calculator (14) having access to the database (11), the calculator (14) being configured to process the initial image (IM) so that: i. Based on the identifier (10A) of the sample (10) and the calculator (14) The database (11) accessed to obtain the sample reference data (D) of the sample (10) imaged on the initial image (IM) ref_E ),as well as ii. obtaining colorimetric data representing the actual color of the sample (10) on the initial image (IM), the so-called sample actual data (D r_E ), The sample reference data (D ref_E ) and the sample actual data (D r_E ) forms parameters related to the coloration of said body area of ​​said individual.

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