BE1030431A1 - Method for cooking a food item in a cooking appliance with a camera device - Google Patents

Abstract

The present invention relates to a method (29) for cooking a food item (6) in a cooking chamber (3) of a cooking appliance (1) with a camera device (15) for observing the food item (6), wherein at certain time intervals from the camera device ( 15) Images of the food to be cooked (6) are recorded and an edge image is generated from the images by means of edge detection, an edge energy value being determined from the edge image as a measure for the edges recorded in the edge image, and at least one setting of the cooking device based on the edge energy value (1) is determined. The present invention further relates to a cooking appliance (1), in particular an oven, wherein the cooking appliance (1) is designed to carry out such a method (29).

Description

1 BE2022/5256

Method for cooking a food in a cooking appliance with a

Camera setup

Technical area

The invention relates to a method for cooking a food item in a cooking chamber of a cooking appliance with a camera device for observing the food item to be cooked.

The invention further relates to a cooking appliance designed to carry out such a method, in particular an oven.

Background of the invention

Cooking appliances, especially ovens, are known from the prior art

Camera devices are known in which a camera image is used to recognize a specific item to be cooked. For example, these are given

Cooking programs are started by the cooking appliance depending on the food detected, which are then run through according to a predetermined sequence.

However, the desired process often becomes disadvantageous due to a fixed procedure

Cooking point not reached or exceeded because there are too many influencing factors

The cooking process is not taken into account.

To solve this problem, it is known from the prior art that

Cooking device depending on one recognized by the camera device

To control the cooking state of the food, in particular to switch it off. For example, from DE 10 2008 042 804 A1 a cooking device with a camera for observing food being cooked is known. The images recorded by the camera are sent to an external device for playback on a display and are also stored in the cooking device. The cooking appliance has a comparison unit for comparing two images taken at different times in order to obtain one

Identify tanning progress. The image of the food to be cooked can also be used to evaluate the image accordingly

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Evaluate the degree of cooking and thus automatically control and/or end the baking process.

EP 3 715 721 A1 describes a method for operating a cooking appliance and a cooking appliance in which images of a cooking area are captured with a camera. The images are evaluated in a processing device. Image elements that change over time are identified and labeled as such

assigned to the food to be cooked so that it comes from outside the food to be cooked

to distinguish between image elements. Color coordinates can be used in the LAB

Color space can be considered to see whether they change or not. An increase in browning can also be observed and the baking process can be stopped when a certain browning level is reached.

From DE 10 2019 107 819 A1 a method for operating a cooking appliance is known, in which a camera device measures the size of the

The food to be cooked is repeatedly determined and a change in size is determined from this. At least one cooking state for the cooking process is determined by the fact that the change in size reaches or falls below a threshold. In DE 10 2019 107 846 A1, such a measure of the size of the food to be cooked is compared with the size at a reference time and the time course of the relative value thus formed is used to assess the cooking state.

Description of the invention

Based on the background of the invention, it is an object of the present invention to propose a method by which the

Cooking process can be better controlled.

The object of the invention is achieved by the features of the independent

Main claims resolved. Advantageous refinements are in the

Subclaims specified. If technically possible, the teachings of the

Subclaims can be combined as desired with the teachings of the main and subclaims.

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In particular, the task is solved by a method for cooking a food to be cooked in a cooking space of a cooking appliance with a camera device for observing the food to be cooked, at certain time intervals from the

Camera device images of the food to be cooked are taken and by means of

Edge detection is used to generate an edge image from the images, an edge energy value being determined from the edge image as a measure for the edges detected in the edge image, and at least one setting of the cooking appliance being determined based on the edge energy value.

Advantageous aspects of the claimed invention are explained below and preferred modified embodiments of the invention are explained below

Invention described. Explanations, especially regarding advantages and

Definitions of characteristics are essentially descriptive and preferred, but not limiting, examples. If an explanation is limiting, this will be expressly mentioned.

A cooking appliance is designed in particular as an oven, in which the

Preparation of a food, for example, temperatures of around 100-250 ° C are provided in the cooking space. The cooking appliance can also be used as an oven with a

Pyrolysis function, a steam cooking function and/or with an integrated

Be designed as a microwave. The cooking appliance can also be used as a steamer,

Be designed as a microwave or stove.

The cooking chamber of the cooking appliance is preferably a cavity insulated from an outer wall of the cooking appliance by means of thermal insulation

Housing of the cooking appliance is formed. The cooking space can preferably have one

Opening can be filled with food or such food can be removed from the cooking space via the opening, the opening being closed by means of a

Cooking compartment door can be locked. Means are preferred in or on the cooking space

Heating and/or means for circulating the air in the cooking chamber are provided. Furthermore, means for emitting radiation can be used in the cooking chamber

Heat and/or for transferring heat by means of heat conduction and/or

Induction may be provided.

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The camera device is arranged in particular outside the cooking space, with a viewing window being embedded in a cooking space wall through which the

Camera device can observe the food being cooked. This is preferred

Camera device arranged above the food to be cooked, i.e. above the cooking space, and looks from above onto the area that is intended for arranging the food to be cooked. The camera device can also be arranged on the side of the food or cooking space and can look laterally onto the area mentioned.

An arrangement with an oblique perspective on the food to be cooked is also possible. The camera device includes, for example, a 2D camera

However, alternatively or additionally a 3D camera, for example as a TOF camera

Camera designed, have.

Edge detection is used to identify which areas in the images

Edges run. To do this, a respective area is examined for differences in neighboring pixels, for example based on brightness, gray or color values or based on textures. Such an examination is preferably carried out using edge operators that are applied to the images and, for example, from a two-dimensional convolution of the image with the

Edge operator exists. In particular, for each pixel, an immediate environment consisting of a certain number of pixels surrounding the pixels is considered and an average gradient of one or more pixel values is calculated for this purpose. The

The average gradient can be weighted by the coefficients of

edge operator. For example, a Sobel operator or a Scharr operator can be used as the edge operator. For each pixel, the gradient can be formed based on the environment and the edge operator, which has a sign. For example, a positive sign indicates one

Change from light to dark, while a negative sign

Change from dark to light. Depending on the orientation of the operator, this relationship can also be the other way around. This creates a gradient image.

The operators are often structured in such a way that a folding occurs

Form gradients in the x or y direction. The overall gradient for a pixel is then composed of the x and y directions and is formed, for example, by the root of the sum of the squared direction values, the Pythagoras. This allows the amount to be calculated while neglecting the direction of the

Create an edge from the individual fold results. Instead of a convolution with an edge operator, an image and a corresponding operator can alternatively be transferred to a frequency range and multiplied there. Instead of a single pixel, a group of pixels can also be viewed.

An edge image is then formed by determining the amount of the pixel by pixel

Gradients are formed and or the individual gradients are mathematically summarized in the direction, for example using simple

Addition or using Pythagoras. Each pixel is uniquely one

Assign the gradient amount and then form the edge image with the sum of the other pixels. In a further embodiment, the image is binarized in such a way that for the pixels for which an edge is sufficient to be recognized

Gradient in the environment was determined, a first pixel value and for the

Pixel without sufficient gradient in the environment, which is therefore assigned to an area, a second pixel value that can be distinguished from the first pixel value

Pixel value is set. So the edge image has pixels with binary

pixel value. For example, the first pixel value is 0% saturation and the second pixel value is 100% saturation, or the first pixel value corresponds to a different color value than the second pixel value. In any case, the edge image can be used to distinguish between pixels assigned to an edge and one

Pixels assigned to the area can be distinguished. An edge image can be used as an actual image from those recorded by the camera device

Images are derived or as a file that does not correspond to an image in the true sense, for example as a binary matrix of the values zero and one, each with one entry for each pixel considered.

An edge energy value is understood to be a measure that is a statistical measure such as mean, variance, root mean square over the number of

represents gradient values or the edge image. The edge energy value therefore increases when the number of edges, their summed length and/or

6 BE2022/5256 whose summed width increases and therefore more pixels in the edge image have a high gradient or edge value.

The above solution to the problem now includes the teaching that the edges of the food to be cooked are examined based on the edge energy value in order to use the

Edge energy value to control the cooking device. It was recognized that the

Edge energy value changes for many foods during the cooking process, especially as the food changes size. From one like this

Change information can be derived from which the

Cooking process can be controlled. For example, such a change can be assigned to a cooking state of the food to be cooked. For some foods, it is also possible to use the progression to determine the properties of the food and to derive the control of the cooking device from this. The course of the

Edge energy value therefore follows a characteristic course over at least part of the cooking process, based on which a cooking state or a

Properties of the food to be cooked can be derived. The cooking device is controlled based on this characteristic course and the food is cooked more precisely. For this purpose, the cooking process is preferably repeated

Edge image is generated and an edge energy value is determined from this.

By assessing the cooking process based on the edge energy value, or by determining the at least one setting based on the edge energy value representing the cooking process, the cooking process is particularly advantageously tailored to the respective composition of the food to be cooked and is independent of a fixed program sequence. It is therefore not important whether information about the composition of the food to be cooked is known, but rather the influence that the composition has on the cooking process is reflected in the determined edge energy value and is therefore reflected in the

procedures taken into account.

The food can preferably be viewed through the camera device or through

Evaluation of images from the camera device are automatically recognized by the cooking device or by manual input, for example at a

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Program selection can be set, in which case the characteristic course that is expected for the edge energy value for this food to be cooked, or at least values derived from it, can be stored in a storage device of the cooking appliance and used for the method. At least one

Setting of the cooking device that is determined is, for example, one

Cooking temperature, a heating curve, a switch-off time or a

Switch-on time of at least one means for heating or cooling the

cooking space or the food being cooked or a position of the cooking space door. Particularly preferably, the edge energy value is continuously determined during a cooking process and the cooking process is controlled in full, i.e. with regard to all relevant settings, and in particular according to the edge energy value

Completion of the food finished. By ending the cooking process based on the edge energy value, i.e. switching off the cooking device, it is particularly advantageous to prevent the food being cooked from overcooking, drying out or burning. Switching off can preferably also be done in an energy-saving manner before the food is fully cooked, so that the food can be cooked with the im

The remaining heat in the cooking chamber finishes cooking.

The determination of the edge energy value through edge detection makes it possible, particularly when baking several lying on a baking tray

Foods to be cooked in an oven during the baking process

Change in shape, a particularly advantageous control of the

cooking process, for example for cookies or croissants.

In particular, a cooking process for baked goods with leavening agents that have a pronounced rise during baking can be carried out via the

Edge energy value can be controlled advantageously.

In one embodiment of the method, the edge energy value is determined from the

Edge image as the mean of pixel values, as the square mean of the

Pixel values and/or determined as the variance of the pixel values. The

Edge energy value can be determined easily and with little power from a data processing device using the calculation methods mentioned.

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In one embodiment of the method, at least one cooking state of the food to be cooked is determined based on the edge energy value. Such a cooking state is therefore derived for a food item from the course of the edge energy value, in which the edge energy value follows a characteristic course corresponding to the cooking state at least over part of the cooking process.

This is particularly the case with foods that are cooked through the cooking process

Change size. For example, meat is made through the loss of

Liquid decreases during cooking, as do vegetables. Food to be cooked with

When baking in an oven, leavening agents increase in size due to the leavening agent and then shrink again due to the loss of liquid after the leavening agent is used up. For such items to be cooked, the cooking process can then be ended, for example, when the achievement of a desired cooking state is recognized based on the edge energy value.

In a further embodiment, the course of the

Edge energy value determines at least one property of the food to be cooked.

For example, when baking cookies in an oven that consist primarily of butter and flour, spreading occurs at the beginning of the baking process due to the melting of fats in the cookie dough. Such widening is accompanied by a significant change in the edge energy value, as the outer edges of each cookie are affected by the rising

Circumference become longer. The edge energy value can therefore be used to track the widening. However, in the further baking process after spreading, there is no longer a significant change in the edge energy value. It therefore becomes from the

Course of the edge energy value during the widening at least one

Property of the food to be cooked is derived, on the basis of which the setting, for example a baking time or a cooking space temperature, is determined.

In particular, a spatial dimension, a mass, a surface and/or a thermal capacity of the food to be cooked is determined as at least one property. The property-specific property determined can also represent a mixture of several individual properties and can, for example, be assigned to a ratio of thermal mass to surface area. The

9 BE2022/5256 property specific to the food being cooked correlates very well with the actual one

Property of the food, but is never exactly the food technology

Characteristic. The property can then be used, for example

Model calculations an ideal progression of cooking device settings over the

cooking process can be determined. For example, one of the mentioned can

Properties in a calculation of the core temperature of the food to be cooked or

The course of this core temperature flows over time.

Determining at least one property based on the edge energy value is also possible for food items for which the edge energy value is used

Cooking state can be recognized in the course of the cooking process, in which there is a connection between the course of the edge energy value and the

Cooking status exists. In one embodiment, the at least one setting of the is based on the cooking state and the at least one property

cooking appliance. For example, the detected doneness is then compared with a doneness calculated based on the property and an adjustment is only made if there is a plausible match. The cooking appliance is therefore controlled based on several values, so that a stable process is achieved in which the incorrect or incorrect determination of one

setting is avoided.

Particularly preferably, a time for switching off the cooking appliance is determined based on the cooking state and/or the property. It will then be a

Undercooking, overcooking or burning are safely avoided. In particular, there is no need to specify a cooking time and no observation of the cooking appliance by an operating person. It can also depend on the

Edge energy value when assumed or recognized as sufficient

Cooking state triggers a method for detecting browning of the food to be cooked, which is carried out using the camera device and causes the cooking device to be switched off when sufficient browning is detected.

In particular, depending on the food to be cooked, a time for switching off can be determined by the edge energy value or a method for

Detecting browning can be triggered.

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In a further embodiment, the images recorded by the camera device are first blurred, converted into a gray image and/or reduced in resolution to generate the edge image. Softening - also called blur in image processing - advantageously eliminates high-frequency effects in the image such as pixel noise or

Reflections on the food or in the cooking chamber are eliminated from the image and are therefore not reflected in the edge image. The process is therefore stabilized in such a way that external interference is suppressed. The reduction of the

Resolution and/or a conversion to a gray image serve to minimize the file size of the image and thus enable a simplified

Processing the image in a corresponding data processing device that is intended to carry out the method. The ones from the

Images captured by the camera device can be used to create the

Edge image can be reduced in resolution, for example using an image pyramid. A gray image with reduced resolution still enables one

Determination of a meaningful edge image or edge energy value, based on which an assignment to a cooking state or the determination of at least one property of the food to be cooked and in this respect the determination of at least one setting of the cooking device is reliably possible.

Preferably, at least one image recorded by the camera device is derived from an image recorded by the camera device

Image, at least one edge image and/or at least one edge energy value stored in a storage device. It is then advantageous even after that

At the time at which the image was recorded, the derivative was formed from it or the edge image was generated or the edge energy value was determined, it is possible to generate the edge image again or determine the edge energy value or check the edge image or the edge energy value.

In particular, the stored data can also be evaluated and used

Error detection and/or improvement of the process can be used.

This is particularly preferred and has the advantages already described above

Cooking device designed as an oven for baking a baked good, whereby the

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Cooking chamber is designed as a baking muffle. The process is then used in particular when baking baked goods that are during the

Baking has a significant change in shape, such as cookies,

Baking croissants, rolls or other baked goods with raising agents such as

cake or bread. In particular, the method points to several on one

Baking tray has advantages for baked goods lying in the oven.

The task is also solved by a cooking appliance, in particular an oven, for cooking a food item, having a cooking space and a

Camera device for observing the food being cooked, with the cooking device being used

Executing a previously described method is designed. In particular, the cooking appliance has a data processing device that is set up to carry out the method. Furthermore, the cooking appliance preferably also has a storage device for storing data. The cooking appliance then has the advantages described above with regard to the method.

Brief description of the drawings

The invention is explained below with reference to the attached

Drawings explained in more detail using preferred exemplary embodiments. The

Formulation Figure is abbreviated as Fig. in the drawings.

Show in the drawings

Fig. 1 is a schematic sectional view through a cooking appliance according to one

aspect of the invention;

2 shows a diagram of an edge energy value determined according to one aspect of the invention over time for a first item to be cooked;

Fig. 3 is a diagrammatic representation of the edge energy value determined according to one aspect of the invention over time for a second

food to be cooked; and

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Fig. 4 is a process diagram of a method according to one aspect of

Invention.

Detailed description of the exemplary embodiments

Figure 1 shows a cooking appliance 1 designed as an oven with a housing (not shown) and a cooking space 3 arranged in the housing.

The cooking chamber 3 has an upper side through a first cooking chamber wall 4.1, a lower side through a second cooking chamber wall 4.2, a front side through a third cooking chamber wall 4.3 and a rear side

Side limited by a fourth cooking chamber wall 4.4, with the cooking chamber 3 continuing to a right by cooking chamber walls, not shown

side and limited to a left side. There is one in the cooking chamber 3

Food carrier 5 arranged on which food 6 rests. The

Cooking chamber walls 4.1, 4.2, 4.4 can be insulated from the housing in a manner not shown.

The third cooking chamber wall 4.3 is formed by a cooking chamber door 7, whereby the

Cooking chamber door 7 can be swung open to open or close an opening 8 of the cooking chamber 3. The cooking chamber door 7 is formed from multiple glazing, has a handle 7.1 and is sealed against the first cooking chamber wall 4.1 by means of a seal 10.

A camera device 15 is arranged above and outside the cooking chamber 3. There is a between the camera device 15 and the cooking space 3

Viewing window 9 embedded in the first cooking chamber wall 4.1. The

Camera device 15 is directed downwards and observes what is happening in the

Food 6 located in the cooking space 3 through the viewing window 9 in a top view, as indicated by a viewing cone of the camera device 15.

The cooking appliance 1 also has a data processing device 16

Executing a method, in particular for processing images of the

Camera device 15 and for determining at least one setting of the

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cooking appliance 1. In addition, the cooking appliance 1 has a storage device 17

Save data on.

Figure 2 shows the course of an edge energy value, which is repeated by means of

Edge images generated by edge detection were determined during the cooking process of several cookies on a baking tray in an oven, with the camera device observing the baking tray from above. On the x

The time in minutes is plotted on the axis, and the amplitude of the y-axis is plotted

edge energy value. The edge energy value shown in Figure 2 was taken as

The average value of the pixel values in the edge image is determined and entered

Measure for the image components recognized as edges in the edge image. It can be seen that the edge energy value at the beginning of the baking process from about

Minute 5 increases significantly. This increase is due to the cookies spreading, which occurs when the fat contained in the cookies melts as the baking temperature or core temperature of the cookies increases. When the fat melts completely, the edge energy value reaches

Maximum 22. After maximum 22, the edge energy value slowly decreases again due to the cookies drying and the resulting contraction.

From the time at which the maximum 22 is reached, from the amplitude of the

Edge energy value at maximum 22 and/or from the slope that the

Edge energy value until the maximum is reached is 22

Properties of the cookies can be derived. For example, cookies with a high fat content spread further apart than cookies with a low fat content. So, for example, based on the maximum 22 the

Fat content is determined, this can be used, for example, to determine a baking time and / or an ideal baking temperature in the further course of the baking process. In a similar way, for example, from a flat

Slope of the edge energy value up to a maximum of 22 can be inferred from a large mass of the individual cookies, and based on this

Property a baking time and / or baking temperature can be determined.

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Figure 3 shows the course of the edge energy value corresponding to Figure 2 during the cooking process of several baking croissants on a baking tray in an oven, with the camera device again observing the tray from above. It can be seen that after a warm-up phase approximately

Minute 8 the edge energy value increases significantly, which is due to the opening of the

croissants to the side is caused by the leavening agent they contain. For the

At maximum 22, the croissant has reached its maximum volume.

At this point in time, a downstream edge energy evaluation can be applied

Step like an analysis of the browning. The croissants are finished baking in about nineteen minutes.

When it comes to baking croissants, you can also use the time and date

The necessary baking time can be estimated using the amplitude of the maximum 22 and the slope before the maximum 22. It can also come from further

The course of the edge energy value can be inferred from the cooking state and, for example, from a threshold value below which the edge energy value drops again relative to the maximum 22, a fully baked croissant can be assumed.

Figure 4 shows a process diagram of a method 29 according to one aspect of the invention. In a first step 30, an image of the food 6 is taken from the

Camera device 15 captured. In a second step 31, an edge image is created from the image by edge detection, for which purpose the image is, for example, previously blurred, converted into a gray image and/or reduced in resolution. In a third step 32, at least one edge energy value is determined from the edge image, for example by forming the average value of all

Pixel values in the edge image or as the variance of these pixel values. In a fourth step 33, at least one is determined based on the edge energy value

Setting of cooking appliance 1 is determined.

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Reference sign list 1 cooking device 3 cooking machine 4.2 Guard room wall 4.2 Second cooking space 4.3 Third cooking space 4.4 Fourth cooking wall 5 cooking carrier 6 Gargut 7 cooking door 7.1 Handing the cooking door 8 Opening 9 view window 15 camera device 17 memory device 22 maximum 29 procedure 30 first step 32 third step 33 fourth step

Claims (12)

16 BE2022/5256 patent claims 1. Method (29) for cooking a food item (6) in a cooking chamber (3) of a cooking appliance (1) with a camera device (15) for observing the food item (6); wherein images of the food (6) to be cooked are recorded by the camera device (15) at certain time intervals and an edge image is generated from the images by means of edge detection; wherein an edge energy value is determined from the edge image as a measure for the edges detected in the edge image; and wherein at least one setting of the cooking appliance (1) is determined based on the edge energy value. 2. Method (29) according to claim 1, wherein the edge energy value is determined from the edge image as the mean value of pixel values, as the square mean value of the pixel values and / or as the variance of the pixel values. 3. Method (29) according to claim 1 or 2, wherein at least one cooking state of the food (6) is determined based on the edge energy value. 4. Method (29) according to one of the preceding claims, wherein at least one property of the food to be cooked (6) is determined based on the course of the edge energy value. 5. Method (29) according to claim 4, wherein at least one property is determined as a spatial dimension, a mass, a surface and / or a thermal capacity of the food (6). 6. Method (29) according to one of claims 3 to 5, wherein the at least one setting of the cooking appliance (1) is determined based on the cooking state and the at least one property. 17 BE2022/5256 7. Method (29) according to claim 6, wherein a time for switching off the cooking appliance (1) is determined based on the cooking state and / or the property. 8. Method (29) according to one of the preceding claims, wherein the images recorded by the camera device (15) for edge detection are first softened, converted into a gray image and / or reduced in resolution. 9. Method (29) according to claim 8, wherein the images recorded by the camera device (15) for edge detection are first reduced in resolution by means of an image pyramid. 10. Method (29) according to one of the preceding claims, wherein at least one image recorded by the camera device (15), an image derived from an image recorded by the camera device (15), at least one edge image, and / or at least one edge energy value in one Storage device (17) are stored. 11. Method (29) according to one of the preceding claims for baking a baked product in a baking sleeve of an oven. 12. Cooking appliance (1), in particular an oven, for cooking a food item (6), having a cooking chamber (3) and a camera device (15) for observing the food (6), the cooking appliance (1) being used to carry out a method (29 ) is designed according to one of the preceding claims.