DE102014107899A1 - Method and device for testing a food product to be pelleted in a pelleting operation - Google Patents

Abstract

In a method for testing a food product to be pelletized to determine whether the pel has been completely removed from the product, at least one image of the product is taken and by evaluating the image, it is checked whether at least part of the pel still exists on the product is.

Description

The present invention relates to a method and apparatus for testing a food product to be pelleted in a pelletizing operation to determine whether the pellet has been completely removed from the product.

Machines for pilling food products, such as sausages, are known. A Pellmaschine is for example in the EP 2 187 750 B1 described.

In a pelletizing operation performed in a pelletizing machine, there may be a problem that the pellet is not completely removed from the product. For example, the skin may crack while it is being pulled from the product, leaving the uncoated portion of the skin on the product.

In order to check whether the pellet has been completely removed from a product during a pelletizing operation, it is known to use photocells to detect a part of the pellet drawn from the product. However, this is disadvantageous in that a tip of the pelae and / or pellet residues of a few square centimeters size remaining at the rear end of the product are difficult or impossible to detect by the light barriers on the circumference of the product.

Moreover, it is known to use a metal detector for detecting a clip attached to the tip of the pelle. In this way, however, only a metallic clip can be detected, whereas a clip made of plastic is not detectable. In addition, such metal detectors are relatively expensive and it can only be determined that the clip has been removed. Conclusions on the entire Pelle are not possible.

The present invention has for its object to provide an improved method or an improved device for examining a food product to be able to determine with relatively little effort and high security, if at least residues of Pelle are present on the product.

The object is achieved by a method having the features of claim 1 or by a device having the features of claim 18. Preferred developments and embodiments of the invention are specified in the dependent claims.

In the method of the invention for examining a food product to be pelletized to determine whether the hide has been completely removed from the product, at least one image of the product is taken and tested by evaluating the image to see if at least a portion of the hide is present on the product.

The process can be used to control the proper operation of the pelletizing process. Products that have not been completely peeled can be recognized and, for example, removed, so that they can be reworked.

The present invention is based on the idea to determine by image analysis of at least one image of the product, whether the Pelle was completely removed from the product. In particular, the process may be carried out following a pelletizing operation to check whether pellets have remained on the product during the pelletizing operation. The process can also be carried out already during the pelletizing process. For example, the front end of the product, viewed in the conveying direction of the product, can already be examined for the presence of pelle while the rear end of the product is still being peeled.

By means of the method according to the invention, in particular the entire product can be examined completely for the presence of pellet residues. Preferably, only one subregion of the product is recorded per image. The entire product can thus be examined for the presence of pellet residues by taking pictures of different parts of the product. The recorded images can each be evaluated individually, superimposed or assembled to form an overall image that reflects the entire product and that is evaluated for the presence of pellet residues.

With the method according to the invention arbitrarily small pellet residues can be recognized on the product. In practice, however, it may be sufficient if pellet residues are detectable from a size of about one square centimeter, since in a faulty pelleting normally only larger pellets remain on the product.

For image acquisition, the product can be conveyed through an image pickup area. In this case, an image of the respective part of the product, which is located in the image pick-up area, can be recorded. The image recording area can correspond to the field of view of an image recording device, such as a camera.

Alternatively or additionally, the image pick-up area can be moved along the product. The image recording area can thus be moved along the conveying direction, so that they sweep the entire product and thus the entire Product can be included in multiple pictures.

Preferably, the product is at least partially rotated about its longitudinal axis, while the product is conveyed through the image-receiving area and / or the image-receiving area is moved along the product. By turning the product, a product part facing away from the image pickup area can be moved into the image pickup area and thus taken up. For example, the image pick-up area can correspond to the field of view of a camera which looks from above onto a conveying path for the product. If the product is conveyed through the field of view of the camera without rotation, only the area of the product facing the camera can be picked up. By rotating the product about its longitudinal axis, the area of the product opposite the camera can be brought into the image-recording area and thus likewise recorded.

According to a preferred embodiment of the invention, the image pick-up area is moved at least partially in the circumferential direction of the product, in particular back and forth, while the product is conveyed through the image pick-up area and / or the image pick-up area is moved along the product. The product can thus be absorbed essentially over its entire circumference.

According to a preferred embodiment of the invention, the image pick-up area is moved in the longitudinal direction of the product and thereby seen in the circumferential direction of the product upper half of the product, especially in multiple images, the product then rotated by a predetermined angle, for example, 180 degrees about its longitudinal axis and Then, the image pick-up area is moved counter to the longitudinal direction and thereby the lower half of the product, in particular in several pictures taken. This allows the entire product surface to be easily absorbed.

The images obtained can then be checked to see if there are any remaining pellets on the product.

Preferably, the image pickup is started as soon as a front end of the product enters the image pickup area. The image acquisition can therefore already take place while the Pelle is still subtracted from the rear end of the product.

Preferably, the product is completely absorbed, in particular by means of several images. Thus, the entire product can be checked for the presence of pellet residues.

The images can be evaluated individually. It can be assumed that the pelleting process has taken place properly if Pelle is not detected in any of the evaluated images. Further, an improper pelleting operation may be inferred when Pelle is detected in at least one of the images.

The images may also be superimposed and / or assembled into an overall image of the product. The overall picture can then be evaluated to see if there is any pelle on the product.

According to a preferred embodiment of the invention, the product is illuminated during image acquisition. As a result, the recognizability of a pellet residue on the surface of the otherwise peeled product can be improved since, in particular, the contrast between the residual pellet and the product surface or the environment can be improved by the illumination.

Preferably, the product, in particular depending on the product and / or the pelle, illuminated directly or diffusely. A direct illumination or a diffuse or reflection illumination is used depending on the constellation, nature and / or pairing of product and Pelle.

According to a preferred development of the invention, in particular between the taking of two images, from a direct to a diffuse illumination, or vice versa, switched. The part of the product located in the image pick-up area can thus be recorded both under direct and under diffuse illumination.

The product is preferably illuminated with a light color and / or light intensity which depends on the product and / or the pelle. As a result, the recognizability of parts of the pelel remaining on the product in the image evaluation can be improved via the contrast and / or the brightness and / or color distribution.

Preferably, the light color is changed, in particular between the taking of two images. The product or at least parts of the product can thus be illuminated and recorded with different colors. As a result, the recognizability of residual pellets in the product can be further improved in the image analysis, since a plurality of images taken with different illumination colors can be evaluated, thereby increasing the likelihood that pels remaining on the product will actually be recognized in the images.

According to a preferred embodiment of the invention, at least part of the image is evaluated with regard to one or more shapes or contours, with respect to the brightness distribution and / or with respect to the contrast distribution and / or with respect to the color distribution, since in this way the skin is simply distinguished from the product and the environment and thus can be detected.

Each captured image, and in particular each captured image of the rear end of the product, may be evaluated to see if there is a pimple of the pelple, assuming there is no pel on the product at all, when it is determined that no pinnacle is present. Surprisingly, it has been found that in most improperly completed pellet operations the tip remained on the product, so that the criterion of whether the eartip is present on the product is well suited to providing a statement as to whether at least a portion of the product Pelle is present or no Pelle at all is present.

The test can be carried out on the basis of a comparison of the recorded image with at least one reference image of at least one peeled subregion of a reference product, whereby the partial region of the reference product recorded in the reference image preferably corresponds at least approximately to a part of the product recorded in the image. By comparing the actual image, ie the recorded image, with the desired image, ie the reference image, it can be easily determined whether Pelle is still present on the recorded subregion of the product.

As a reference image, at least one recorded image of the product or an image of a, in particular peeled, reference product of the same kind can be used. As a reference image, it is thus preferable to use a previously recorded image of the same product, which is checked for the presence of pellet residues, or an image taken on a reference product of the same kind.

The use of an image taken on the same product as a reference image is possible because - if there is still pelle on the product - usually differences between the image and the reference image are detectable, which allow a statement about whether Pelle still exists on the product. For example, if the pelletizing process does not proceed properly, pelle may have remained on the product part that was picked up in the image while there was no pel on the product part that was picked up in the reference image. Such a difference between image and reference image can be detected, whereby the presence of Pelle on the product can be detected. As another example, an outline of a pellet residue left on the product part taken in the image may be different than the outline of a pellet residue left on the product part taken in the reference image, so that it can again be determined by comparing the two images, whether there is still pelle on the product.

The reference image (s) used may also have been classified as completely free of Pelle, for example by a person supervising the proper performance of the procedure.

Preferably, in the image recording device with which the product images are taken, the exposure time or the shutter time is set or optimized on the basis of images taken on sample products and / or on pattern pelts. This can improve the recognizability of Pelle in the recorded images.

Reference images can also be stored in a memory. By entering product parameters, such as product grade and / or color and / or type of pellet, and / or by entering batch parameters, such as the type of pre-cooling of the products, into a controller, the controller may select one or more suitable reference images from the stored reference images to check for presence of Pelle.

A contour of the reference product present in the reference image can be compared with a contour of the product present in the recorded image, and if the two contours agree at least within a predetermined tolerance, it can be assumed that the skin has been completely removed from the product. A comparison of the contours can be carried out by means of an automated, computer-based image analysis in a short time.

The product may be labeled and / or discharged if it is determined that at least part of the pelene is present on the product. The product can then be aftertreated, for example by manually removing the remaining part of the pellet.

It is particularly advantageous if the at least one recorded image is a thermal image which is evaluated for the presence of pelvic on the product with regard to one or more shapes or contours, with respect to the brightness distribution and / or with regard to the contrast distribution and / or with regard to the color distribution. By recording and evaluating a thermal image can on the presence of pellet residues on the product surface can be detected in a simple manner since in the thermal image a pellet residue normally has a slightly warmer image than the actual product surface. The pellet residue can be detected, for example, by evaluating the contrast distribution in the thermal image.

According to a preferred embodiment of the invention, at least one mirror is used for image recording, by means of which a part of the product facing away from an image recording device is visible to the image recording device. With the help of the mirror thus product parts or areas can be recorded, which would otherwise not be visible to the image pickup device.

By using mirrors, the number of image recording devices can be reduced since, as mentioned above, regions which are not visible to an image recording device can be made visible via mirrors, whereby additional image recording devices can be saved.

Preferably, the mirror is adjustable. By adjusting the mirror, the image pick-up area of the image pickup device, which is deflected by the mirror, can likewise be adjusted and thus moved along the product, for example.

The image recording device is preferably adjustable, in particular in order to align it with a mirror.

By using one or more mirrors, even for the guidance of the light from a lighting device, a simplified and / or space-saving overall structure can be achieved, which can be cleaned well and is easily accessible and visible. For example, the image pickup devices may be integrated in a common housing, so that they have a small footprint. By cleverly arranging the mirrors, it can further be achieved that the entire product surface can be picked up by the image recording devices.

Due to the space-saving overall design, the recording path along the - seen in the product conveying direction - the image is taken, be kept compact. The ability to integrate into existing plants improves with it.

The invention further relates to an apparatus for inspecting a food product to be pelletized in a pellet process for whether the pellet has been completely removed from the product, comprising image pickup means for picking up at least one image of the product and an image evaluator adapted thereto by evaluating the image to verify that at least part of the pelé is still present on the product.

The image recording device can have an image recording area, by means of which the product can be conveyed to receive the at least one image.

Alternatively or additionally, the image recording device can be moved such that an image recording area in the longitudinal direction of the product and / or in the circumferential direction of the product, in particular back and forth, is movable.

According to a preferred embodiment of the invention, a rotating device may be provided, by means of which the product is rotatable about its longitudinal axis.

The rotator may be coupled to the image capture device to synchronize the product rotation with the image capture.

The image recording device may comprise at least one image sensor, in particular a camera.

Preferably, two, three or four image sensors are provided which, viewed in the circumferential direction of the product, are arranged offset from one another, in particular such that at least approximately the entire product circumference can be detected by the image sensors.

The image sensor or sensors may be disposed at an angle in the range of 90 degrees or less to the longitudinal axis of the product.

At least one illumination device can be provided for illuminating the product, in particular during image acquisition. The lighting can be integrated into the camera or provided as additional lighting. A combination of these arrangements is conceivable.

Preferably, the illumination device can be switched between a direct and a diffuse illumination.

The light color of the light provided by the illumination device can be adjustable.

Preferably, the light intensity of the light provided is adjustable. According to a preferred embodiment of the invention, a pelletizing machine is provided for carrying out the pelletizing operation, the image-receiving device being arranged downstream of the pelleting machine and / or the pelleting process or pelletizing process or integrated into the pelleting machine in the conveying direction of the product.

Preferably, the image recording device is a thermal imaging camera and the image evaluation device is designed to evaluate a thermal image recorded with the thermal imaging camera with respect to one or more shapes or contours, with regard to the brightness distribution and / or with respect to the contrast distribution and / or with regard to the color distribution to the presence of pelvic on the product ,

At least one mirror can be provided, by means of which at least one part of the product facing away from the image recording device becomes visible to the image recording device.

The invention will now be described by way of example with reference to the accompanying drawings. Show, in each case schematically,

1 a device according to the invention for testing a food product,

2 a further device according to the invention for testing a food product,

3 a top view of another device according to the invention for testing a food product,

4 a front view of yet another device according to the invention for testing a food product,

5 a top view of yet another inventive device for testing a food product,

6 a front view of the device of 5 , and

7 a front view of yet another device according to the invention for testing a food product.

In the 1 illustrated device 1 is to study a food product 3 , such as a sausage, provided to determine if any on the product 3 originally existing Pelle 5 in one of a pellet machine 7 completed pelleting process was completely removed. The device 1 comprises an image recording device designed as a camera 9 and one with the image pickup device 9 coupled image evaluation device 11 that in one with the pellet machine 7 coupled control 13 is integrated.

The pellet machine 7 For example, according to the in the EP 2 187 750 B1 be formed pellet machine described. The pellet machine 7 hands over the product 3 following the pelleting process to a conveyor 15 such as a conveyor belt, which is the product 3 promotes F in a conveying direction. The image capture device 9 is above the conveyor 15 arranged and can the product 3 capture while it is from the conveyor 15 is conveyed by an image pickup area corresponding to the field of view of the camera.

The image capture device 9 at least take a picture of the product 3 and transmits the image to the image evaluation device 11 , which checks by evaluating the image, if at least part of the Pelle 5 on the product 3 is available.

For example, the image pickup device takes 9 a picture of the back end 17 of the product 3 on. The image evaluation device 11 checked by evaluating the image, whether at the rear product end 17 a corner 19 the Pelle 5 is available. If it is found that the corner 19 no longer exists, then it is believed that the Pelle 5 completely from the product 3 was removed. The presence of the corner 19 can thus be used as a decision criterion, whether generally on the product 3 still Pelle 5 is present or whether the product 3 was completely peeled. In the context of the present invention, however, the entire product surface is preferably examined for the presence of Pelle.

The image analysis then, if the tip 19 still on the product 3 can be performed by comparing the captured image with at least one reference image of a peeled product. The reference image can be in the image evaluation device 11 be saved. For example, an existing in the reference image contour of the rear end of the reference product with a present in the captured image contour of the rear product end 17 be compared to determine whether the contours agree at least approximately. If a coincidence of the two contours is determined within a predetermined tolerance range, it is assumed that there is no corner in the recorded image 19 is pictured and thus the product 3 was completely peeled.

Alternatively or additionally, it is also possible to compare with regard to specific brightness, contrast and / or color values or to search for specific brightness, contrast and / or color patterns in the recorded image.

Not shown are a device for buffering and sorting out incorrectly peeled products and a device for slicing food, also referred to as a slicer is seen in the conveying direction F of the image pickup device 9 can be subordinate.

The control 13 can with a controller 21 be coupled to the pellet machine and output to this a signal when it is determined that the tip 19 at the rear end of the product 17 still exists. The product is then removed from the loading buffer to be manually reworked or post-bleached and to avoid the product 3 is cut open while the corner 19 reaches the area of a cutting knife of the slicer. Thus it can be prevented that one at the corner 19 possibly provided metal clip damaged the cutting blade.

The device 1 of the 2 corresponds essentially to the device of 1 , In addition, however, is still a lighting device 29 provided, which is tunnel-like and the detection range of the image pickup device 9 covers. Is shown in 2 a section through the tunnel-like lighting device 29 ,

The in the 3 to 7 illustrated devices 1 are also used to test a food product 3 , such as a sausage, provided to determine if any on the product 3 originally existing Pelle 5 in one of a pellet machine 7 completed pelleting process was completely removed. In the process, the product becomes 3 or whose surface is completely recorded by means of one or more images and by evaluating the images is checked whether still Pelle 5 on the product 3 is available. On the basis of the pictures taken, a check of the entire product surface for presence of Pelle takes place.

In the device 1 of the 3 is an image pickup device (not shown) above the conveyor 15 arranged so that the image pickup device from the top of the conveyor 15 looks. However, the optical axis of the objective of the image recording device does not have to be aligned in the vertical direction, but rather can be set at an angle with the conveying direction F or also against the conveying direction F.

The field of view of the image recording device defines an image recording area 23 , The respective within the image pickup area 23 lying part of the product 3 can be taken in the form of at least one image from the image pickup device. As above with reference to 1 has been described, the image can be transmitted to an image evaluation device, not shown, which checks by evaluating the image, if at least part of the Pelle 5 (see. 1 ) on the product 3 is available.

The conveyor 15 is designed to be the product 3 to promote in the conveying direction F, for example, to supply it to a downstream slicer. In the process, the product becomes 3 through the picture-taking area 23 completely conveyed through. Alternatively or additionally, the image pick-up area 23 along the conveying direction F are moved, so that the image pick-up area 23 the product 3 in its longitudinal direction sweeps. Furthermore, the product 3 around its longitudinal axis 25 be turned while the product 3 through the picture-taking area 23 promoted or the image pick-up area 23 along the product 3 is moved. For example, some kind of intermittent operation may take place, such that the one in the image pickup area 23 lying part of the product 3 is recorded while the product 3 rests. After the image has been taken, the product becomes 3 rotated and / or conveyed along the conveying direction F. Then another picture is taken. The process described is carried out until the entire product surface has been recorded. The images obtained can then be evaluated by an image evaluation unit to see if any pellets residues on the product 3 available.

As another example, the image pickup area 23 against the conveying direction F of the product 3 be moved. In this case, the upper half of the product, the above the conveyor 15 arranged facing image pickup device, taken gradually in multiple images. Subsequently, the product 3 by a predeterminable angle, in the example shown by 180 degrees, about its longitudinal axis 25 turned. Then the image pickup area becomes 23 moved in the conveying direction F and thereby recorded the previous lower half of the product in several pictures. In this way can also gradually the entire surface of the product 3 be recorded. By evaluating the images obtained can also be checked whether the product 3 completely peeled.

In the device 1 of the 4 are three image capture devices 9 in the circumferential direction of the product 3 seen offset from one another arranged such that their image pickup areas 23 cover the product range. By means of the three image recording devices 9 can thus the entire surface of the product 3 be included when the product 3 through the image pickup areas 23 is conveyed through or the image pickup areas 23 along the product 3 be moved. A turning of the product 3 around its longitudinal axis 25 is not required.

It can also only two or more than three, z. B. four or five, image capture devices 9 be provided, their image pickup areas 23 can completely cover the scope of the product, so that the product surface is completely absorbed by the product surface 3 can be omitted.

The product 3 but can still be rotated. In addition, the image capture devices 9 in the circumferential direction of the product 3 seen going back and forth to make sure the product 3 along its circumferential direction completely from the image pickup devices 9 is detected.

In the device 1 of the 5 and 6 are laterally next to the conveyor track for the product 3 semicircular ring segments 27a . 27b arranged. For the sake of clarity is in 6 the ring segment 27b Not shown. On the inside of each ring segment 27a . 27b is an image capture device 9 movably arranged so that the entire surface of the product 3 through the image capture devices 9 the ring segments 27a . 27b can be included while the product 3 at the ring segments 27a . 27b is conveyed past.

In the device 1 of the 7 is above the conveyor track for the product 3 an image pickup device 9 arranged, which is the upper, the image pickup device 9 facing part of the product 3 can record. Laterally next to the conveyor lane are also mirrors 31 attached, by means of which the respective lateral product surface of the image pickup device 9 can be included, cf. the exemplified light paths 33 that run away from the product surface and from the respective mirror 31 to the image recording device 9 be redirected. Of course, you can also use multiple mirrors 31 for deflecting a light path 33 be used.

To magnify the image pickup area, the mirrors can be used 31 for example, a respective, substantially parallel to the longitudinal axis 25 be extending axis of a mirror suspension pivot. In addition, the image capture device 9 be pivoted to this directly on a respective mirror 31 to be able to judge.

The 7 serves as an illustration, like a mirror 31 can be used in connection with image acquisition. Of course, more mirrors 31 or image capture devices 9 be provided, in particular such that the product 3 can be recorded over its entire circumference.

In the described devices 1 can, as with the device of 2 , in addition at least one lighting device 29 be provided. Preferably, each image pickup device is 9 or a group of image capture devices 9 a separate lighting device 29 assigned. By means of the lighting device 29 the contrast between any pellet residue and the product surface in the captured images can be increased. In addition, a direct or diffuse lighting can be accomplished. Furthermore, the light color and light intensity in the lighting device can be adjustable.

In the examples described above, the respective image pickup device is 9 to a camera. Alternatively, the image pickup device 9 be configured in the form of a single or multi-line image sensor and include, for example, one or more CCD sensors.

In the image pickup device 9 it can also be a thermal imaging camera, by means of which a temperature measurement of the surface of the product 3 can be done. At the same time, a pellet residue remaining on the surface should give a slightly different image than the actual product surface. A thermal image recorded with the thermal imager can thus be evaluated, for example, with regard to the contrast distribution, in order to check whether pellet residues are still present on the product.

LIST OF REFERENCE NUMBERS

1

 contraption

3

 Food product

5

 skin

7

 peeling machine

9

 Image recording device

11

 image evaluation

13

 control

15

 Conveyor

17

 rear end

19

 tip

21

 Loading buffer control or slicer control

23

 Imaging area

25

 longitudinal axis

27a, 27b

 ring segment

29

lighting device

31

 mirror

33

 light path

F

 conveying direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2187750 B1 [0002, 0068]

Claims (25)

Method for testing a food product to be pelleted in a pelletizing process ( 3 ) to see if the pellet ( 5 ) completely from the product ( 3 ) at which at least one image of the product ( 3 ) and, by evaluating the image, it is checked whether at least part of the skin ( 5 ) on the product ( 3 ) is available. A method according to claim 1, characterized in that the product is used for image acquisition ( 3 ) through an image pickup area ( 23 ) and / or the image recording area ( 23 ) along the product ( 3 ). Process according to claim 2, characterized in that the product ( 3 ) about its longitudinal axis ( 25 ) is at least partially rotated while the product ( 3 ) through the image pickup area ( 23 ) and / or the image recording area ( 23 ) along the product ( 3 ). Apparatus according to claim 2 or 3, characterized in that the image-receiving area ( 23 ) at least partially in the circumferential direction of the product ( 3 ), in particular to and fro, while the product ( 3 ) through the image pickup area ( 23 ) and / or the image recording area ( 23 ) along the product ( 3 ). Method according to one of claims 2 to 4, characterized in that the image recording area ( 23 ) in the longitudinal direction of the product ( 3 ) and one in the circumferential direction of the product ( 3 ) seen in the upper half of the product, the product ( 3 ) then by a predeterminable angle about its longitudinal axis ( 25 ) and the image pickup area ( 23 ) Then proceed against the longitudinal direction and thereby the lower half of the product is added. Method according to one of claims 2 to 5, characterized in that the image acquisition is started as soon as a front end of the product ( 3 ) in the image pickup area ( 23 ). Method according to one of the preceding claims, characterized in that the product ( 3 ), in particular by means of several images, is completely recorded. Method according to one of the preceding claims, characterized in that the product ( 3 ) is illuminated during image acquisition. Process according to claim 8, characterized in that the product ( 3 ), in particular depending on the product ( 3 ) and / or the Pelle ( 5 ), is illuminated directly or diffusely, and / or that, in particular between the taking of two images, from a direct to a diffuse illumination, or vice versa, is switched. Process according to claim 8 or 9, characterized in that the product ( 3 ) with one of the product ( 3 ) and / or the Pelle ( 5 ) dependent light color and / or light intensity is illuminated, and / or the light color, in particular between the taking of two images, is changed. Method according to one of the preceding claims, characterized in that at least part of the image is evaluated with regard to one or more shapes or contours, with respect to the brightness distribution and / or with regard to the contrast distribution and / or with regard to the color distribution. Method according to one of the preceding claims, characterized in that the test is carried out on the basis of a comparison of the recorded image with at least one reference image of at least one peeled subregion of a reference product, wherein, preferably, the sub-region of the reference product recorded in the reference image at least approximately one part recorded in the image of the product ( 3 ) corresponds. A method according to claim 12, characterized in that as a reference image at least one recorded image of the product ( 3 ) or an image of one, in particular peeled, reference product of the same kind is used. Method according to claim 12 or 13, characterized in that a contour of the reference product present in the reference image with a contour of the product present in the recorded image ( 3 ), and assuming that the two contours coincide at least within a predetermined tolerance, it is assumed that the plane ( 5 ) completely from the product ( 3 ) was removed. Method according to one of the preceding claims, characterized in that the product ( 3 ) is marked and / or rejected if it is determined that at least part of the pelae on the product ( 3 ) is available. Method according to one of the preceding claims, characterized in that the at least one recorded image is a thermal image relating to one or more forms or Contours, with regard to the brightness distribution and / or with regard to the contrast distribution and / or with regard to the color distribution on the presence of pelle on the product ( 3 ) is evaluated. Method according to one of the preceding claims, characterized gekennzeichn that for image recording at least one mirror ( 31 ) is used, by means of the one of an image pickup device ( 9 ) remote part of the product ( 3 ) for the image recording device ( 9 ) becomes visible. Contraption ( 1 ) for testing a food product to be pelleted in a pelletizing process ( 3 ) to see if the pellet ( 5 ) has been completely removed from the product, with an image recording device ( 9 ) for capturing at least one image of the product ( 3 ) and an image evaluation device ( 11 ), which is designed to check, by evaluating the image, whether at least part of the skin ( 5 ) still on the product ( 3 ) is available. Contraption ( 1 ) according to claim 18, characterized in that the image recording device ( 9 ) an image capture area ( 23 ) through which the product ( 3 ) is receivable for receiving the at least one image, and / or the image recording device ( 9 ) is movable such that an image pick-up area ( 23 ) in the longitudinal direction of the product ( 3 ) and / or in the circumferential direction of the product ( 3 ), in particular to and fro, is movable. Contraption ( 1 ) according to claim 18 or 19, characterized in that a rotating device is provided, by means of which the product ( 3 ) about its longitudinal axis ( 25 ), wherein, preferably, the rotating device with the image recording device ( 9 ) in order to synchronize the product rotation with the image acquisition. Contraption ( 1 ) according to one of claims 18 to 20, characterized in that the image recording device ( 9 ) comprises at least one image sensor, in particular a camera or thermal imaging camera, wherein, preferably, two, three or four image sensors are provided, which in the circumferential direction of the product ( 3 ) arranged offset to one another, in particular such that at least approximately the entire product circumference by means of the image sensors can be detected. Contraption ( 1 ) according to one of claims 18 to 21, characterized in that at least one illumination device ( 29 ) for lighting the product ( 3 ), in particular during image acquisition, wherein, preferably, the illumination device ( 29 ) is switchable between a direct and a diffuse illumination and / or the light color of the illumination device ( 29 ) is adjustable and / or the light intensity of the light provided is adjustable. Contraption ( 1 ) according to one of claims 18 to 22, characterized in that a pelletizing machine ( 7 ) is provided for performing the pellet process, wherein the image pickup device ( 9 ) in the conveying direction (F) of the product ( 3 ) seen the pellet machine ( 7 ) and / or downstream of the pelletizing or pelleting process or into the pelletizing machine ( 7 ) is integrated. Contraption ( 1 ) according to one of claims 18 to 23, characterized in that the image recording device ( 9 ) is a thermal imaging camera and the image evaluation device ( 11 ) is adapted to a recorded with the thermal imager thermal image with respect to one or more shapes or contours, with regard to the distribution of brightness and / or in terms of the contrast distribution and / or in terms of the color distribution on the presence of Pelle ( 5 ) on the product ( 3 ). Contraption ( 1 ) according to one of claims 18 to 24, characterized in that at least one mirror ( 31 ) is provided, by means of which at least one of the image recording device ( 9 ) remote part of the product ( 3 ) for the image recording device ( 9 ) becomes visible.

Images