FR2582804A1 - Methods and devices for determining and checking levels, and in particular levels of a liquid and depth of insertion of a cork in the neck of a series of bottles, in a bottling line - Google Patents

Abstract

The invention essentially relates to a device 1 for checking a batch of bottles 2 moving horizontally on a conveyor 4 in order to check the levels of liquid and insertion of corks in wine bottles, more especially champagne bottles. The device is fitted with a matrix camera 34 with a horizontal optical axis x-x' and grids disposed vertically along y1-y'1. A diffuse light source 48 is situated on one side A of the conveyor 4 and a directional point source 58 disposed on the side B and oriented along 1-1' in the direction of the corks. The originality of the invention resides, on the one hand, in the mode of initializing the device using test bottles having reference marks, on the other hand, in the fact that this device uses a linear camera and, finally, in the mode of confirmation of the levels found.

Description

 The invention relates to an improvement to the methods and devices for determining and controlling levels and more particularly of liquid levels and depth of insertion of plugs inside a batch of containers traveling horizontally on a conveyor.

 In the filling lines, the containers are filled with liquid or product at rates frequently exceeding 10,000 containers per hour. The product is introduced into the container from the top, the neck of the container being open, then the container is closed, in particular using a stopper.

 During all these operations, the containers are moved substantially horizontally one behind the other, on a conveyor.

 The most common method for performing level checks is to place one or more checking employees along the conveyor. These provide visual or sample control at the outlet of the filling and capping lines.

This human method is not very precise, random and lacks reliability.

 In order to satisfy various international provisions relating to consumer protection, it is said, many countries have drawn up very strict legislative texts concerning the metrological control of packaging and containers containing products, in particular food products and liquids and more particularly wine.

 We will take as an example, in the following, the case of champagne bottles.

 The export rules from a country such as France vis-à-vis a country such as the United States require that the average of a lot (daily manufacture of a disgorging line for example) is equal at the nominal quantity provided for the bottles (750 ml).

The maximum permissible error is 15 ml.

 In the case of champagne bottles, at 200, the wine level must be 72 mm below the leveling of the bottle so that it is at its nominal value of 75 cl.

 To take into account the operating parameters, and more particularly the expansion due to temperatures, the nominal level at 100 will be 75.5 mm from the leveling instead of 72 mm.

In order to respect all of these constraints, the
bottlers have given themselves an acceptable range of one
amplitude of approximately 15 mm centered on the nominal value, outside
from which the bottles must be rejected for
meet metrological control standards. As part of
this rule, the percentage of defective bottles, as a result
100% control, must not exceed 2%.

To allow bottlers to faithfully adhere to these
constraints and, moreover, to enable them to act on the
operating parameters of the corking and
filling, it is necessary to develop a device for
level control ensuring continuously on a line conveyor
filling
- detection of overfilled containers
- detection of insufficiently full containers
- detection of plugging levels
- the calculation of the true mean
- the calculation of the number of units produced - - and the determination of the standard deviation.

Very recently, a control system has been developed.
levels on a bottling line. This system is essentially
consisting of a matrix camera capturing an image
rectangular bottle necks scrolling successively on
a conveyor. This matrix array camera is triggered externally
laughing by an additional activated photocell
each time a new bottle begins to pass the
camera. An electronic module digitizes the image and
temporary storage in an image memory. A unit of
image processing, linked to the electronic scanning module and
equipped with a microprocessor, provides computer processing of
the memorized image to isolate the level parameters
distinguishable according to a certain algorithm by their characteristics
of brightness.

The defects of this system are as follows
- on the one hand, the matrix cameras are very
complex due to the density of their networks, which
increases the cost of the system
- on the other hand, storage for processing an image
from a matrix camera requires a memory size
about 250.K bytes
- moreover, each taking into account of an image by the unit
processing requires full memory path
images with a volume of 250 K bytes; this slows down
considerably the functioning of the control device
and limits its treatment possibilities to less than a few
thousands of bottles 1 hour
- finally, the parasite treatment algorithms are very
complex and very slow for raster images
digitized on 250 K bytes.
known are very sensitive to variations in brightness and
stray light; which causes errors
uncontrollable and requires brightness adjustments
frequent.

 The present invention aims to remedy these drawbacks overall.

 The invention, as characterized in the claims, solves the problem of creating a level control device on a batch of containers scrolling horizontally on a conveyor, this device being capable of controlling the level for passage rates larger containers 9 to 10,000 bottles / hour.

 The first object of the invention is to provide such a device at a very advantageous cost because of its simplicity.

 A second object of the invention is to propose a method capable of operating such a device using a linear camera of low cost, without pre-location system of bottles, and allowing the implementation of a fast processing algorithm.

 A third object of the invention is to make it possible to control, with the same device, numerous level parameters such as the level of the liquid, the level of penetration of the stopper, the level of the labels, etc.

 Finally, a fourth object of the invention is to propose a method for initializing the level control device making it possible to immediately adapt the device to the treatment of batches of very different bottles.

 The invention is set out below in more detail with the aid of drawings representing only one embodiment.

On these drawings
- Figures 1 and 2 show, front and side view, the
disposal of the materials constituting the
invention level control
- Figure 3 shows schematically half of a
bottle filled with champagne including various parameters of
levels must be analyzed using the device of the invention
- Figure 4 shows a standard container for
initialize the operation of the device according to the invention
for checking a container according to figure 3
- Figure 5 shows schematically the principle according to the invention of af
allocation - of sensitive areas around levels of
reference
- Figure 6 shows the video signal from the capture with
a linear camera of a vertical portion of a bottle
filled with liquid, according to figure 3
- finally, Figure 7 shows the essential elements of a
level control system according to the invention.

 Figures 1 and 2 show the essential elements according to the invention of the device (1) for level control on a batch of containers (2). The containers (2) are moved in horizontal movement one behind the other using a conveyor shown schematically in (4).

The main organs of the device (1) are brought together inside a casing (6) playing both the role of protection and support for the various elements of the imaging system.

 The housing (6) consists of a lower base (8) delimited by removable side (10) and front (11) stainless steel protective plates screwed to the feet (12,13,14, ...) a metal frame (16). The lower base (8) is surmounted by a protective cap (18) produced by assembling smoked altuglass plates (20), removably mounted on the upper part of the metal frame (16). It is possible to easily set up the protective casing (6) and its elements around a previously installed conveyor by introducing it through passage elements (22) formed on the side walls of the casing (6).

 Note that, on the front face (24) of the lower base (8), is fixed vertically a camera support arm (26), rising vertically. This can be adjusted vertically at various levels by means of screws (28) integral with the casing (6), cooperating with recesses (30) of the arm (26). The upper part of the support arm (26) is provided with a plate (32) on which is fixed a linear camera (34) provided with a lens (36).

 The plate (32) comprises means (33) for horizontal adjustment of the camera (34).

 The camera (34) is placed horizontally along an axis (x-x ') perpendicular to the median vertical axis (y-y') and to the axis of the movement path (z-z ') of the conveyor (4) . The network (40) of photosensitive elements (42,43, ...) constituting the camera sensor (34) is oriented vertically along the axis (yî-y'1) as shown in Figure 5.

 The objective (36) is developed on the median plane (y-y ') of the conveyor to ensure the successive capture of image elements (46) from the containers (2) scrolling past the camera (34).

 It is also noted that the device (1) comprises various lighting means (48-58).

 The first of them consists of a light table (48) located on the second side (B) of the device (1) opposite the camera (34), opposite the axis (y-y ' ) of the conveyor (4).

 The light table (48) comprises, in particular, a vertical series of neon tubes (50) placed inside its volume and a diffusing screen (52) placed vertically opposite the conveyor (4) on the side (B) .

 This light table (48) ensures uniform illumination of the bottles (2) towards the camera (34), so that the contours (54) of the bottles (2) are perfectly sensitive by a backlighting effect.

 It is also noted that the front face (24) of the casing (6) is provided with a second support arm (56) directed towards the interior of the base (8) and on the left part thereof.

 A point light source (58), constituted in particular by a powerful and directional light spot, is fixed by its lower part (59) to the second support arm (56).

 The illumination axis (1-1 ') of the spot (58) is oriented obliquely in the direction of the upper part (5) of the receptacles (2).

 This arrangement is particularly advantageous when checking the levels of bottles, such as champagne bottles (60) closed by a stopper (62). It is shown diagrammatically in Figures 3 and 4.

 In this case, it is recommended by the invention to place the second support arm in the lower part of the casing (6) and on the right or left part so as to tilt the direction (1-1 ') of the light source obliquely. point (58) with respect to the optical axis (x-x ') of the camera (34) and the vertical median plane (y-y').

 The combination between the soft and homogeneous light source of the light table (48) and the punctual, powerful and directional light source of the spot (58), inclined towards the axis (y-y ') of the containers, and in particular of the axis of the bottles (2) of champagne (60), leads to the following results concerning the configuration of the gray levels of the image elements (46) captured by the linear camera (34). These can be seen with reference to FIG. 6 which represents the video signal emitted by the linear camera (34) for a vertical image element of a champagne bottle (2).

 The background (64), materialized by the diffusing screen (52) of the light table (48), has an almost white light intensity (B1). The contours (54) of the container (2) are seen in black shadows, in particular the top of the cap is seen in (N1). The top of the pass is seen in (N2). The ring (72) is seen in (N3). The plug (62), lit substantially tangentially by the spot (58) is seen in gray by one level (G1). The bottom of the cap appears with a transition between black and gray in (NB). The interval (66) between the level (68) of the liquid in the container (2) and the lower part (70) of the stopper (62) is seen in (G2) of a gray substantially more intense than that of the stopper.

 The upper level of the liquid (68) and in particular of the champagne (60) contained in the container (2) is seen in black (NL).

 Finally, the liquid, and in particular the champagne (60), is seen in the area (G3) of a gray whose almost constant intensity is between that (G1) and (G2).

 If we refer again to Figures 1 and 2, we see that the front face (24) of the housing (6) is provided with a support plate (76) located inside the central cavity of the lower base (8).

 On the plate (76) is placed an electronic control and processing unit (78) constituting the brain of the device (1).

 The functional characteristics of the box (78) are shown diagrammatically in FIG. 7. This first comprises a sequencer card (80) responsible for controlling the acquisitions of the photosensitive sensor (38) of the camera (34). It directs in particular the mode of exposure of the various photosensitive elements (42,43) of the network (40), the duration of exposure, the programmable bit period and the frequency of unloading. The selection of the different modes for programming the parameters is carried out via microselectors (82) located on the card.

 In addition, the box includes a conversion card (84).

This constitutes the electronic digitization module responsible for converting the linear video signal (86) from the sensor (38) into digital form under the control of the sequencer card (80).

According to the variants chosen by the invention, the conversion card (84) can perform the following functions
- threshold conversion. In this case, the card will provide
analog signal conversion (86)
vis-à-vis one or more thresholds whose level is
locatable by potentiometer and pixel pre-location
significant,
- or analog conversion and more specifically conversion
analog / digital signal (86) on 8 bits.

As will be discussed later, this card can also perform specific mathematical transformations such as
- derivation of the curve (gradient)
- or integration.

 The transmission of the levels inside the box (78) is ensured by the internal bus (88), in particular according to the protocol (G64).

 The box (78) also includes an image processing unit (90) connected to the conversion card by the bus (88) and provided with a microprocessor system (92) for processing the scanned image and isolate, according to a specific algorithm, the parameters of levels distinguishable by their luminosity characteristics.

 To allow the microprocessor-based system to implement the algorithms recommended by the invention which will be described later and to store the image elements (46) during processing, the box (78) includes different memory cards (94 ).

 Interfacing between display and data exchange devices with the operator, such as an alphanumeric monitor (96) and a printer (98) with keyboard (100), is ensured by means of a specific card inlet and outlet (102).

 Finally, the housing is powered by an electrical power supply (104).

 The original method of the invention is first of all intended to allow rapid initialization of the device (1) for carrying out the control of any batch of containers (2), a copy of which appears in FIG. 3.

 To do this, we make a. standard container (106) of the batch of containers (2) to be checked. It can be seen that the standard container (106) is in all respects topologically in accordance with the containers (2). To achieve this, a container conforming to the batch to be checked is used and it is provided with reference marks (108,109,110,111). The marks (108 to 111) were made from a black self-adhesive tape (112), portions of which have been stuck on the outer wall of the container, perpendicular to the axis (r-r ') of the standard container. (106). Therefore, the reference marks (108 to 111) have light characteristics which can be distinguished from those of the standard container (106), by the network (40) of photo-sensitive elements and the image processing unit (90 Then, via the keyboard (100) of the printer (98), the operator signals to the processing unit (90) the standard distance (11,12,13, ...) between minus two reference marks (109,111), (109,110). Then, the operator places the standard container (106) on the conveyor (4) and places it in front of the objective (36) of the line camera (34). The camera (34) analyzes the vertical image elements (46) of the standard container (106) at various levels and transmits them to the processing unit (90) to determine the number within the image elements (46). pixels (114) separating two reference marks (109,110, ...) from the standard (106).

 We will see in Figures 4 and 5 that each of the reference marks (108,109,110,111) is distinguishable within the image element (46) captured by the camera by black pixels (108 ', 109', 110 'and 111' ).

 By approximation between the determined number of pixels separating two marks (109-110), (109-111), (109-108) and the distances (11,12, 13) indicated to the processing unit (90) between the significant pixels (108 ′, 109 ′, 110 ′ and 111 ′) of the image element (46), the vertical dimension (e) which must be associated with each pixel (42) of the array (40) is deduced therefrom sensitive vertical elements.

 Thus, the operation of the measurement system of the image processing unit (90) of the control device (1) is calibrated.

 Most commonly, at least two reference marks will be used, one of which (109) will materialize the top of the neck (63) of the container (2) and the other mark (111) will materialize the nominal value of the level (68) to control.

 Note that the standard container (106) simply serves as a support for the reference marks (108,109,110, ...). This can therefore be replaced by a simple glass plate moved in front of the camera (34).

 The linear camera (34) consists of a linear network (40) of photo-sensitive elements (42,43) arranged in a row vertically along the axis (yî-y'1) (see Figure 5). The camera (34) therefore captures image elements (46), of elongated rectangular shape constituted by an alignment of pixels (114). During the horizontal movement of each bottle (2) on the conveyor (4), in front of the linear camera (34), the latter successively and quickly captures a series of image elements (46) corresponding to parallel vertical portions of each bottle (2) (as distinguished in Figure 3).

 These image elements (46) are transmitted successively to the image processing unit (90), in digitized form, by means of the electronic digitization and preprocessing unit constituted in particular by the image card. conversion (84).

 An advantageous variant of the invention consists in determining, thanks to the processing unit (90) within each picture element (46), the possible position of the sensitive points (N1, N2, N3, NB, N4) (figure 6) likely to correspond to levels to be checked.

The series of position of sensitive points for each image element (46) of the bottle (2) is successively memorized, then the series of sensitive points isolated for each image element (46) is compared with the series of sensitive points of an adjacent picture element. Confirm, then store the confirmed points on a sufficient number of vertical image elements (46).

 According to a complementary variant of the invention, the characteristics of which are shown in FIG. 5, the standard container (106) is produced by placing a reference mark (108,109,110,111) approximately at the nominal level of each sensitive point of levels to be determined. An analysis of the reference container (106) is carried out according to the method described above to determine the coordinate of the black pixels (108 ′, 109 ′, 110 ′, 111 ′) corresponding to the reference level on the elements on the elements d successive images (46) captured by the linear camera (34). We store, in particular on the memory card (94), the address of each reference level, then an allocation area is delimited around each reference level (Z 1, Z2, Z3, Z4). When checking the batch of bottles (2), only the points (N1, N2, N3, NB, N4) located in an allocation area are retained for each image element (46).

 For reasons of simplification, preference will be given to assignment zones (Z1, Z2, Z3, Z4) surrounding each reference frame (108,109,110,111) so that these are separated.

 This arrangement makes it possible to facilitate and accelerate the algorithm for finding the levels among the possible levels isolated inside the video signal (86) resulting from the acquisition of an image element (46).

 According to a first method for determining the levels, the principle of which appears in FIG. 6, a threshold (S) of light intensity is first fixed. This threshold appears along a horizontal (120) in the diagram representing the light intensity perceived by the objective as a function of the coordinates according to (yl-y'l) of the sensor (38). The threshold (S) is chosen in such a way that the intersection of the threshold curve (120) with the video signal curve (86) of the camera has an intersection according to certain vertical sections of containers (2) which indicates the levels to be determined.

 By comparing the linear video signal (86) from the camera (34) with the threshold (S), the video signal (86) is converted into at least one logic signal. These logical state changes are stored for a succession of parallel vertical image elements (46) of each container (2) captured by the linear camera (34) with the threshold (S). The video signal (86) is converted into at least one logic signal.

These logical state changes are stored for a succession of parallel vertical image elements (46) of each container (2) captured by the linear camera (34).

 A statistical analysis of said state changes is carried out and the most frequent state change is used as the level for each container (2).

 According to a complementary variant, the smallest of them is preferred among the changes of state several times confirmed, in order to take account of the effects of the capillarity of the liquid in the bottle.

 It frequently happens that the batch of transparent containers (2) have fairly dispersed light transmission coefficients. It is recommended by the invention to carry out on the video signal (86), coming from the camera (34), a normalization processing rendering the amplitude of the curve (86) of the video signal, relating to an element of image (46), independent of the light transmission coefficient of the corresponding container (2). To ensure this function, it is proposed by the invention to isolate on the signal (86), corresponding to an image element (46) of a container (2), an opacity parameter accounting for the level of transparency in the light of said container (2) and to subsequently process the image signal (86) by applying to it a transformation integrating the amplitude of said opacity parameter. It is understood that this processing ensures normalization of the signal captured for each of the containers (2) of the lot.

 A first solution for carrying out the above normalization process consists in calculating the mathematical integral (I) of the video signal curve (86) of the signal relating to an image element (46).

 With reference to FIG. 5, it can be seen that the integral (I) is materialized by the surface between the curve of the signal (86) and the axis of the coordinates according to (yî-y11).

 It will be readily understood that the amplitude of the integral (I) accounts for the opacity of the container (2).

 According to this method, the video signal (86) is divided by its integral (I) before carrying out its digital processing according to the preceding methods. This method therefore makes it possible to normalize the signal (86) whatever the light transmission coefficient of the container (2).

 To allow this signal processing (86) to be carried out in real time, it is recommended by the invention to place, inside the control and processing box, a conversion card (84) ensuring, according to a wired process , the integration function of the video signal before its transmission to the microprocessor system for analysis.

 A second solution of the normalization process consists in fixing at least two thresholds (S) of different levels. The video signal (86) of the image elements (46) of each successive container (2) is then converted into logic signals by comparison of the video signal (86) with said thresholds (S). The position of the state change pixels corresponding to each of the two thresholds is located in the form of a double series of coordinates. We study the distribution of the double series of coordinates of dietary changes by their positioning inside or outside the assignment zones (Z1, Z2, Z3, Z4) surrounding the reference levels (108,109,110,111). retain the series whose state changes are suitably located within the assignment zones (Z1, Z2, Z3, Z4) and the levels sought are deduced therefrom.

 To quickly perform this level search and confirmation function, it is also recommended by the invention to introduce inside the control and processing unit (78) a conversion card (84) ensuring in wired logic this function of locating pixels of changes of states according to two thresholds, and possibly of searching for the coordinates of changes of logical states situated inside a given assignment area.

 In order to widen the possibilities of the system, it is proposed by the invention to complete the device (1) for level control by means of taking into account the temperature of the liquid located inside the containers (2). These can be constituted in particular either by a probe successively penetrating inside the containers, or by a probe placed on the liquid distributor inside the containers.

 According to this preferred variant of the invention, there is also added to the device (1) means for correcting the theoretical level of the liquid inside the containers (2) as a function of the expansion of the liquid, due to temperature variations.

 For example, for a bottle of champagne whose nominal leveling at 200 will be 72 mm from the neck, the same nominal leveling will be at 75.5 mm from the neck at 100.

The treatment carried out according to the invention using the device (1) makes it possible to carry out continuously, for rates higher than 10,000 bottles
- detection of overfilled bottles,
- detection of insufficiently full bottles.

 When a defective bottle is discovered by the device (1), the latter emits a specific voltage on an input-output port (102) which makes it possible to activate means for isolating the defective bottle from the rest of the batch. .

Continuously, the microprocessor system displays on the monitor (96)
- the number of units produced,
- the number of defective bottles,
- the calculation of the real average
- and the standard deviation.

 At the end of the day, a list containing the above information, recalling the line number and the measurement date, is published on the printer (98).

The invention having now been described and its interest justified
on detailed examples, the applicants reserve the exclusive
for the duration of the patent, without limitation other than
that of the terms of the claims below.

Claims (20)

1. Method for initializing the level control on a batch of  containers (2) running horizontally on a conveyor (4),  ensuring the horizontal displacement of said containers (2) one  behind the other, the method being implemented using a  level measuring device comprising  - a camera (34) fixedly mounted on a first side (A) of the  conveyor (4) comprising a sensor (38) consisting of  a series of photosensitive elements (42,43, ..) arranged  according to a network (40), this camera (34) being placed  horizontally along (x-x '), perpendicular to the axis  (z-z ') to the path of movement of the conveyor (4), and the  network (40) of photosensitive elements (42,43, ..) being  vertically oriented along (yî-y'1), said camera (34)  being further provided with a lens (36) developed  substantially on the median plane (y-y ') of the conveyor (4)  to ensure successive capture of image elements (46)  scrolling past the camera (34) in the form of pixels,  - means of lighting (48,58) of the containers (2) challenge  lant on the conveyor (4),  - an electronic digitization module (84) ensuring the  thresholding and digitization of the video signal (86) supplied by  the sensor (38) in the form of bits,  - an image processing unit (90), connected to the module  digitizing electronics (84), provided with at least one  microprocessor (92) ensuring processing of the elements  digitized images (46) to isolate, according to an algorithm  specific, the level parameters distinguishable by  their brightness characteristics,  said method, intended to allow rapid initialization for  check any batch of containers (2),  being characterized in combination in that, previously at the  start-up of the control using the measuring device (1),  - an element, and in particular a standard container, is produced  (106) of the batch of containers (2) to be checked by placing on  a support conforming to those of said batch, at least two  reference marks (108,109,110,111), placed  perpendicular to the vertical axis (y-y ') of the element  standard (106) and having light characteristics  distinguishable by image processing unit (90) from  those of the standard container (106),  - to be served on the processing unit (90), in particular by  via an alphanumeric keyboard (100), the  standard distance (l1,12,13, ..) between at least these two  reference marks (109,110), (109,111),  - placing the standard element (106) on the conveyor (4) in front  the camera (34) and to analyze the image of this standard (106) at  using the processing unit (90) to determine, at  within the image (46), the number of pixels separating the two  reference marks (109, 110, etc.) of the standard (106),  - finally, to deduce from this within the processing unit (90) the  vertical dimension associated with each pixel of the element  image (46) of the containers (2), so as to calibrate the  operation of the unit measurement system  image processing. 2. Method according to claim 1 above, for controlling ni  calves on a batch of containers (2) running horizontally on  a conveyor (4), characterized in that  - one of the reference marks (109) is constituted by the  top of the neck (63) of the container (2),  - and the other mark (111) also materializes the nominal value  level of the level to be checked. 3. Method according to one of claims 1 and 2 above, of  level control on a batch of scrolling containers (2)  horizontally on a conveyor (4),  said method being intended to facilitate the determination of each  level to control and increase reliability, including  - using a linear camera (34) constituted by a network  linear (40) of photosensitive elements (42,43) arranged on  a row oriented vertically along the axis (yl-y'l),  this camera capturing a picture element (46) of form  vertical longilinear rectangular constituted by a  pixel alignment,  - to grasp, during the movement of each bottle  in front of the linear camera (34), a series of elements  images (46) corresponding to parallel portions  vertical of each bottle (2),  - to be transmitted successively to the processing unit  images (90l, via the electronic module  (84) preprocessing, successively the image elements  (46) of each bottle (2),  said process being characterized in that  - it is determined, thanks to the processing unit (90), within  of each picture element (46), the possible position of the  sensitive points (N1, N2, N3, NB, N4) likely to  correspond to levels to be checked,  - the series of sensitive point positions is memorized  isolated for each elongated picture element (46) of the  bottle (2),  - we compare the series of isolated sensitive points for a  picture element with the series of hotspots of a  adjacent picture element, and validate by memorizing them  the points that we find on a sufficient number  vertical picture elements (46). 4. Method according to claim 3 above, for controlling  levels on a batch of containers (2) scrolling horizontally  on a conveyor (4);  this process being intended to increase the reliability of the control,  said process being characterized in that  - the standard container (106) is produced by placing a reference  reference (108,109,110,111) approximately at  nominal level of each sensitive point to be determined,  - lton performs an analysis of the reference container (106)  according to the method of claim 1 for determining the  coordinates of the corresponding pixels (108 ', 109', 110 ', 111')  at reference levels on the picture elements (46)  successive captured by the linear camera (34),  - the address of each reference level is stored,  - we surround each reference level with a zone  assignment (Z1, Z2, Z3, Z4),  - and, when checking the batch of bottles (2), we do not retain  for each picture element (46) that the sensitive points  possible, close to a level of benchmarks, located in the  corresponding assignment area. 5. Method according to claim 4 above, for controlling  levels on a batch of containers (2) scrolling on a conveyor  (4), said method being characterized in that one chooses,  so that they are separate, the assignment areas  (Z1, Z2, Z3, Z4) surrounding each reference level (108,109,  110,111). 6. Method according to one of claims 3 to 5 above, of  level control of a batch of scrolling bottles (2)  horizontally on a conveyor (4), said method being  characterized in that, to determine the levels  - we set a threshold (S) so that the interaction of  this threshold curve (120) with the curve of the video signal  (86) of the camera (34), at least in certain slices  vertical containers (2), indicates the levels at  determine,  - the linear video signal (86) from the camera is converted  (34) in at least one logic signal by comparison with said audit  threshold,  - the logical state changes are memorized for a  succession of vertical image elements (46) parallel to  each container (2), captured by the linear camera (34),  - we perform a statistical analysis of the changes  of states,  - as the level, for each container (2), the  most frequent change of state. 7. Method according to claim 5 above, for controlling  levels of a batch of containers (2) scrolling horizontally on  a conveyor (4), intended to avoid inaccuracies due to the  upper meniscus and the presence of foam covering the  liquid,  said process being characterized in that  - the statistical study determines changes  states; these state changes several times confirmed  - and the smallest of them is retained as the level.  8. Method according to claim 7, for controlling levels on a  batch of transparent containers (2), and in particular of bottles  liquid, comprising a stopper (62) and intended to determine  both the level (110) of insertion of the plug (62) and the  level (111) of the liquid in the container (2),  said process being characterized in that the  container (2), in combination using  - a powerful point light source and direction  nelle, like a spot (58), located on the first side of the camera  opposite the conveyor,  - and a homogeneous light source, such as a table  light (48), located on the second side of the conveyor.  9. Method according to claim 8 above, for controlling  levels on a batch of transparent containers (2), and in particular  liquid bottles fitted with a stopper (62), for  determine both the level (110) of driving in the plug  and the level (111) of the liquid in the container (2),  said process being characterized in that the axis is oriented (1-1 ')  of illumination of said point light source (58) in  direction of the cap (62) of the container (2). 10. Method according to one of claims 8 and 9 above, of  level control on a batch of transparent containers (2),  and in particular of liquid bottles, fitted with a stopper  (62),  said process being characterized in that  - the lighting direction (1-1 ') of the source is tilted  point light (58) vis-à-vis the optical axis (x-x ')  of the camera (34) and of the vertical (y-y '). 11. The method as claimed in claim 10, for controlling  levels on a batch of transparent containers (2), and in particular  liquid bottles, fitted with a stopper (62),  said process being characterized in that  - it is tilted, from bottom to top, and sideways  the direction (1-1 ') of illumination of the light source  point (58) with respect to the optical axis (x-x ') of the  camera (34).  of the corresponding container (2).  (46) independent of the light transmission coefficient  the amplitude of the curve (86) relative to an image element  normalization processing making, at least in part,  - applying to the signal (86) from the camera (34) a  said process being characterized in that  a conveyor,  different light transmission, running horizontally on  transparencies, such as glass bottles, with a coefficient of  level control inside a batch of containers (2)  12 Method according to one of claims 1 to 11 above, of 13. Method according to claim 12 preceding, of control of  levels inside a batch of containers (2> transparent, of  different light transmission coefficient, scrolling hori  horizontally on a conveyor,  said process being characterized in that  - the signal (86) corresponding to an element is isolated  image (46) of the containers (2) an opacity parameter  reporting the level of transparency to light  of said container (2),  - and lson processes the image video signal (86) by applying it  a transformation integrating the amplitude of said parameter  opacity, so as to normalize the signal entered for each  containers (2) from the batch. 14. Method according to claim 13 above, for controlling  levels inside a batch of transparent containers (2),  different light transmission coefficient, moving  horizontally on a conveyor (4),  said process being characterized in that  - the integral video (I) is isolated from the video signal (86)  - and we divide the video signal (86) by its integral before  perform its digital processing, so as to standardize  the signal regardless of the transmission coefficient of  container light (2). 15. Method according to claims 4 and 12 above, of  level control inside a batch of containers (2)  transparencies, such as glass bottles, z-z coefficient of  different light transmission running horizontally on a  conveyor, the levels can be detected by the  crossing of light intensity thresholds,  said process being characterized in that  - at least two thresholds of different levels are set,  - the video signal (86) of the image elements is converted  (48) of each successive container (2) in the form of  logic signals, by comparison of the video signal (86)  with said thresholds (S),  - we locate a series of state change pixels  corresponding to each of the thresholds,  - we study the distribution of the double series of coordinates  changes of state, by their positioning at  inside or outside the assignment areas (Z1, Z2,  Z3, Z4) surrounding the reference levels (108,109,110,  111),  - we retain the series whose state changes are  suitably located within the assignment areas (Z1, Z2, Z3, Z4),  - we deduce the levels sought. 16. Device (1) for level control on a batch of containers  (2) scrolling horizontally, intended to implement a  method according to one of claims 1 to 15, this device  comprising in combination  - a conveyor (4) ensuring the horizontal movement of  containers (2) one behind the other,  - a camera (34) fixedly mounted on a first side of the  conveyor, comprising a sensor constituted by a series  photosensitive elements arranged in an array, this  camera being placed horizontally, perpendicularly  to the path of the conveyor, and the network of elements (42,43)  photosensitive being oriented vertically, said camera  (34) being further provided with a lens developed on the  mid-plane of the conveyor to ensure successive entry  of picture elements (46) scrolling past the camera under the  shape of pixels,  - means of lighting (48,58) of the containers (2)  running on the conveyor (4),  - an electronic module (84) for digitization ensuring  thresholding and digitization of the signal supplied by the sensor  in the form of bits,  - an image processing unit (92), connected to the module  electronic digitization (84), provided with at least one  microprocessor ensuring the processing of the digitized image  to isolate the parameters of levels distinguishable by  their brightness characteristics,  said device being characterized in that its camera (34) is  of the linear CCD type, that is to say that its sensor (38) is  consisting of a linear network (40) of photosensitive elements  (42,43) arranged in a row (yî-y'1) oriented vertically  is lying. 17. Device (1) according to claim 16, level control  on a batch of transparent containers (2),  said device (1) being characterized in that its system  lighting includes a light table (48) located on the second  side of the conveyor. 18. Device (1) according to claim 18, level control  liquid inside a transparent container (2) as well as  in particular the level of depression (110) of the plug (62),  said device (1) being characterized in that its means  of illumination (48,58) consist of the combination between  - a light table (48) located on the second side (B) of the  conveyor (4),  - and a light source (58), point and directional  like a spot located on the first side (A) of the conveyor (4). 19. Device according to claim 18, for controlling the level (111)  liquid inside a transparent container (2) as well as  in particular the level of penetration (110) of the plug (62),  said device being characterized in that its said source  point light (58) is inclined, oriented from bottom to top  and from the side, in the direction (1-1 ') of the plug (62). 20. Device according to one of the preceding claims 16 to 19,  characterized in that it further comprises - means for taking the temperature into account - and means for correcting the theoretical level of liquid  inside the containers (2) depending on the expansion  some cash.