EP1044826B2 - Method for recording images - Google Patents

Abstract

The method of inscribing a data carrier (10) with pictorial information. involves obtaining characteristics relevant to recognition by means of a spatial analysis of the original picture, by using filters. A line drawing is obtained in vectorized f by the intermediate storage and or the inscribing of the picture on the data carrier. The line drawing is transformed or integra in a security background (6) of the data carrier.

Description

The invention relates to a method for recording image information on a data carrier.

A known data or recording medium for colored or colorful image information ( EP 0 537 484 A1 ), which is used in particular as a value or identity card, consists of a card inlay acting as a light-scattering background and a transparent film arranged thereon, on which a color-receiving layer is arranged. The transparent film serves as a substrate into which optically recognizable information can be inscribed by carbonizing or blackening the film material with the aid of laser radiation. The ink-receiving layer can be printed in color by applying or introducing dyes.

To record a colorful or colored image on this known recording medium, the image information of the image to be recorded is first decomposed into a light / dark component and at least one color value extract, as a colored component. The light / dark portion is then written by means of a laser beam writer in the transparent film, resulting in the more or less blackened areas of a gray-scale image. Subsequently, the color value extract (s) of the image information is then superimposed on the gray-scale image by applying or introducing appropriate dyes onto or into the color-receiving layer.

Although this known method makes it possible to apply colorful images relatively tamper-proof on disk, but it provides no advantages for the visual recognition of images. The visual recognition arises almost exclusively through the analysis of geometric contexts and shapes in the image, where colors present in the image are of little importance for the recognition of the image. In some cases it has even been shown that the colors present in a picture not only do not improve recognition processes, but may even hinder them. Such effects are known in psychology as, for example, "color shock". Also in recognition service test series such color shock effects were detected.

However, the mere generation of a light / dark portion for physical protection of a photo or image on a disk is not only a recognition service of no advantage, but also aesthetically problematic, since the brilliance of the color information by an additionally applied black and white information in the substrate normally is significantly affected. Such a gray haze can be compensated only very limited by increasing the color saturation in the originally applied color information.

The US 5,421,619 concerns an identity card with a laser image. On this card is an authentic high resolution photographic image of the authorized card user and a macroscopic two-level (bi-level) image applied. In order to obtain this two-level image consisting of only either black or white pixels from the original image, a so-called "dither matrix" consisting of pixel thresholds is applied to the high-resolution image. In this case, a light or a dark value are determined for each pixel or each pixel, depending on whether the corresponding original value of the pixel is greater or smaller than the threshold value of the "dither matrix" to be used.

The image obtained in this way can easily be burned into a data carrier with the aid of a laser. Recognition-relevant features, in particular characteristic facial features, however, can not be determined here. Rather, this type of image processing deteriorates the recognizability, since in the original image existing contrasts and contrast gradations are practically completely eliminated.

The US Pat. No. 3,805,238 shows a method according to the preamble of claim 1.

Based on this, the object of the invention is to provide a further method for recording image information on a data carrier with which it is possible in particular to easily record a brilliant color image in a forgery-proof manner so that it is easily recognizable.

This object is achieved by the method according to claim 1. Advantageous embodiments and further developments of the method according to the invention are described in the subclaims.

According to the invention, therefore, in addition to an image corresponding to an original image, processed or unprocessed, characteristic facial features are recorded in visually recognizable form on the data carrier which were obtained from the original image as recognition-relevant features. In this way, a complete color image with high brilliance and resolution can be applied to the data carrier, wherein the visual recognition of the image is improved by the additional recording of identification-relevant features. If the original image is in particular a portrait photograph which is to be recorded on the data carrier as a so-called passport image, the method according to the invention makes it possible to apply the photograph to a document serving as a data carrier so that it is aesthetically acceptable to the owner of the document , at the same time, however, has an increased recognizability for purposes of identification purposes.

The method according to the invention therefore makes it possible in particular to separate identification features of a photograph from the aesthetic features and to introduce them into the data carrier in a physically secure manner. The advantage lies in the fact that the aesthetic design of the photo, for which the color plays a major role, can be realized in a separate step, independently of the design that ensures the recognizability of the photo or image.

Preferably, the identification-relevant Characteristics obtained by a spatial analysis of the original image, wherein the spatial analysis is applied to one or more color separations of the original image.

To obtain recognition-relevant characteristics, spatial filters are used. By spatially filtering the image information with a spatial filter or with a suitable combination of spatial filters, the edges and lines present in the image to be recorded are obtained, so that with a suitable choice of the filter or filters used after filtering only a line drawing or a so-called "sketch" is present. This line drawing or sketch alone is sufficient to be able to recognize the image to be recorded, especially under identification service aspects without confusion.

For the extraction or extraction of the identification-relevant features, similar to a caricature, the image or the image information is initially reduced by iteratively omitting non-essential details, that is, details which do not promote or even preclude recognizability. In a second phase, the reduced information is then transformed so that it can be realized physically visible in the most economical manner possible.

In order to improve the human recognizability of faces while reducing the data, the invention provides that a line drawing is obtained as recognition-relevant features from the original image, which in the intermediate storage and / or recording the image on the disk, especially in vectored form is realized.

In order to improve the recognizability of a human-like portrait at the same time as the aesthetic impression, it is expedient if the identification-relevant features are superimposed in register with the recorded image.

In an expedient development of the invention, it is provided that, after recording the image, its position on the data carrier itself is recorded and the identification-relevant features are recorded on the data carrier in accordance with the detected image position. As a result, the image to be recorded and the identification-relevant features can be recorded on the data carrier in a particularly simple manner, in particular with exact registration, without the need for special adjustment or alignment marks on the data carrier.

It is particularly expedient if, for better visibility of the identification-relevant features, the recorded image is the original image that has been suitably transformed or reduced in terms of its color and / or spatial information content.

To further improve the security against counterfeiting, it can be provided that the line drawing is transformed or integrated into a security background of the data carrier.

Another possibility is that the identification-relevant features without direct spatial reference to the recorded image are recorded on the disk.

The identification-relevant features obtained from the original image can therefore be recorded in various ways on the data carrier, the respective species being able to be used individually or in combination. For example, it is possible to integrate the identification-relevant features present as a line drawing into the security background of the data carrier as well as to overlay them in register with the portrait photo. The recording without a direct spatial reference can also be combined with the precisely fitting recording and the integration of the identification-relevant features in the background.

If the identification-relevant features are to be applied to the data carrier only as a sketch without a direct spatial reference to the recorded photo, then it is particularly advantageous if the identification-relevant features are recorded on a specific area of the data carrier which is prepared for the realization of double or tilt image effects ,

In order to improve not only the counterfeit security of the data carrier but the overall data security during the production of the data carrier or document, it is provided that after recording the image whose image information is detected in order to determine the recognition-relevant features that are to be recorded in addition to the image.

In an advantageous embodiment of the invention, the image is applied to a suitable for applying information image bearing surface of a substrate having a data carrier, and the identification-relevant features are written by means of radiation in the substrate.

This procedure is particularly advantageous if, for example, passport pictures or other images individualizing the data carrier which are stored in a central data memory are to be recorded in corresponding peripheral devices on the data carrier. Since the entire image information is first applied as a color image, the data connection to the central data memory or computer can be terminated after the application of the colored image. The determination and writing of the image identification features to be additionally inscribed can then be carried out in the peripheral device without the need for a data connection that might impair the security of the data. Another advantage is that the proportion of the total image that is to be additionally recorded correlates particularly precisely with the overall image content.

In a further embodiment of the invention It is envisaged that the radiation used to record the identification relevant features not only causes blackening of the substrate, but also controllably modifies the previously applied image by evaporation or burning so as to visually emphasize the features relevant to the identification.

On the other hand, it is also possible for the identification-relevant features recorded under the previously applied image to be written into the substrate without destruction of the recorded image by means of radiation in the substrate.

The recording of the desired image information can be realized in a particularly simple manner when the identification-relevant features are written into the substrate by means of laser radiation, preferably by means of infrared laser radiation.

A further embodiment of the invention is characterized in that the identification-relevant features for generating further effects, such. As watermarks or the like can be used.

It is particularly expedient if the image-carrying surface is produced by coating the substrate provided for recording the identification-relevant features.

• Fig. 1 eine schematische Draufsicht auf einen vereinfacht dargestellten Datenträger, insbesondere auf eine Ausweiskarte,
• Fig. 2 einen schematischen Schnitt durch einen Datenträger mit darauf aufgezeichneten Bildinformationen,
• Fig. 3 einen Schnitt durch einen anderen Datenträger mit darauf aufgezeichneten Bildinformationen und
• Fig. 4 ein vereinfachtes schematisches Blockdiagramm einer Vorrichtung zum Einschreiben von Bildinformation in ein Substrat eines Datenträgers mittels Strahlung.

The invention will be explained in more detail below, for example, with reference to the drawing. Show it:

• Fig. 1 a schematic plan view of a simplified illustrated data carrier, in particular on a badge,
• Fig. 2 a schematic section through a disk with recorded image information,
• Fig. 3 a section through another disk with recorded image information and
• Fig. 4 a simplified schematic block diagram of an apparatus for writing image information into a substrate of a data carrier by means of radiation.

In the various figures of the drawing corresponding parts are provided with the same reference numerals.

In FIG. 1 For example, an identification card is shown as a data carrier 10 having a recording surface 1 with a labeling area 2, an image area 3, a special effect area 4 and a general information area 5. A security background 6, which is only indicated purely schematically and greatly simplified, can be provided in individual or all regions 2 to 5 of the recording surface 1.

In order to brilliantly record a picture, in particular a portrait photo of the authorized owner of a data carrier 10 serving as a badge, that the recognition-relevant features, ie in particular the characteristic facial features, are clearly recognizable, features relevant to the recognition are obtained from the original image, which then in addition to a Image area 3 image to be applied to the disk 10 recorded. The extraction of the identification-relevant features can also be carried out after recording the image. The image to be recorded, which is preferably printed as a color image 15, may be the original image itself or a processed image in which recording errors have been eliminated both for aesthetic and for identification reasons.

The identification-relevant features are preferably obtained by a spatial analysis of the original image, but can also be obtained from one or more color separations of the original image. The use of the color separations for obtaining identification-relevant features has the advantage that color boundaries can be determined at which the brightness value does not change and therefore can not be detected if only the brightness distribution or luminance of the original image is used to determine identification-relevant features ,

The determination or extraction of the recognition-relevant features from the original image with the aid of spatial filters serves to generate an additional image, in particular as a sketch or line drawing, that contains only more recognition-relevant features. In this case, the amount of image data can be drastically reduced, in particular if the identification-relevant features exist as a line drawing in vectored form.

In particular, if the identification-relevant features are present as line drawings, they can be integrated, for example, into the security background 6 or also recorded elsewhere on the recording surface 1 without a direct spatial reference to the image area 3.

In particular, it is possible to arrange the line drawing in a special effect area 4, which is prepared for example for so-called tilt image effects, in which the image recorded there depends on the viewing angle, as it is z. B. is recorded and viewed by a grid of cylindrical lenses.

In addition to or instead of the recording of the identification-relevant line drawing at arbitrary locations of the recording surface 1, it is preferably provided that the identification-relevant features in the image area 3 are superimposed in register with the recorded image.

The following is based on the FIGS. 2 and 3 First, the structure of the data carrier for use with the method according to the invention described.

As FIG. 2 shows the disk 10 consists of a substrate 11, which is formed for example of a transparent plastic layer, in the image information by means of radiation, in particular laser radiation, preferably infrared (IR) laser radiation is inscribed. For this purpose, the plastic material of the substrate 11 is blackened with the aid of the radiation, for example by carbonizing suitable additives and / or the plastic material of the substrate by the laser radiation. Thus, blackened pixel areas 12 are formed in the substrate 11. The substrate 11 is laminated, for example, to a white carrier layer 13 made of plastic or paper and printed on its surface 14 facing away from the carrier layer 13 with a color image 15. The color image 15 is composed of corresponding color pixels 16 or color image areas, which consist of conventional dyes which are applied in conventional printing processes.

The color image 15 is covered by a transparent protective layer 17, which may consist for example of a printed paint layer applied to the image-carrying surface 14.

As FIG. 2 In order to increase the security against forgery, the pixel areas 12 may be formed in the substrate 11 so as to partially extend into the carrier layer 13. In addition, the color image 15 is formed by color pixels 16 'formed by incorporating dyes into a color-receiving overcoat 18. The cover layer 18 may additionally be coated by a protective layer, not shown, or at the same time serve as such.

For the application of the method according to the invention, which will be explained in detail below, any other data carrier with a transparent by radiation transparent substrate and an image-bearing surface can be used. Here, various single or multi-layered structures are possible. In the case of a data carrier in which the white carrier layer 13 can be printed with ink, the surface 13 'carrying the substrate 11 can also be used as the image-carrying surface.

In principle, the identification-relevant features of the image information can be written into the substrate 11 before printing or introducing the color image 15. As will be described below, however, it is preferable to first apply the color image 15 and then use as recognition-relevant features e.g. B. to write the contour portion in the substrate 11.

According to the method of the invention, for recording image information on the data carrier 10, a processed or unprocessed image corresponding to the original image is applied to the corresponding image-bearing surface as a complete color image.

If the surface 13 'of the carrier layer 13 is used as the image-bearing surface, the color image 15 is first applied. Subsequently, the substrate 11 is then laminated for writing further image information and thus the data carrier 10 is prepared for the next process step.

If the surface 14 of the substrate 11 is used as an image-bearing surface, the writing of the identification-relevant features into the substrate 11 can be carried out with the aid of laser radiation either immediately after the printing of the color image 15 or after the application of the protective layer 17. It can be provided that when recording the identification-relevant features, the previously applied color image is changed in a controllable manner by evaporation or burning in the detection-relevant features so that the identification-relevant features are highlighted.

In the case of using the ink-receptive cover layer 18, the writing of the identification-relevant features preferably follows immediately after the recording of the color image 15.

Thus, after the color image 15 has been applied to the data carrier 10 and this is prepared for writing image information into the substrate 11, the identification-relevant features are additionally written into the substrate 11 with the aid of IR laser radiation.

For this purpose, the card-shaped data carrier 10, to which the complete color image 15 (only black-and-white in the drawing) is applied, is arranged in a processing position in a laser engraving system 19, as described in US Pat FIG. 4 is shown schematically.

The laser engraving system 19 comprises a laser 20, which is controlled by a computing and control unit 21. A deflection unit 22, which is likewise controlled by the computing and control unit 21, deflects the laser beam 23 in order to obtain a writing beam 23 'which scans the data carrier 10. In addition, an image pickup device 24, which may be a video camera, for example, arranged so that it detects the positioning of the data carrier 10 in the laser engraving system 19 or preferably the position of the color image 15 on the disk 10 relative to the processing position in the laser engraving 19. It is also conceivable, instead of using a separate image recording device 24, to use the deflection unit 22 as image scanning unit and to assign it an optical receiver arrangement. The optical detection of the position of the data carrier 10 and the color image 15 thereon then takes place with the aid of the same optical elements with which the writing beam 23 'is guided via the data carrier 10. For detecting the position of the data carrier 10 and the color image 15 in the working position of the laser engraving system 19, however, any other optical position detection device can be used which is suitable to supply position data for controlling the laser 20 and the deflection unit 22.

After the data carrier 10 carrying the complete color image 15 has been arranged in the laser engraving system 19, the position of the color image 15 is detected, in particular with the aid of the image recording device 24. For this purpose, for example, provided on the disk 10 position marks can be used, which were used in the printing of the color image 15 for its positioning. It is preferred, however, if used together with the color image 15 stamps (not shown), since in this case the position of the marks relative to the color image 15 is aligned virtually without manufacturing tolerance. Another particularly preferred possibility is to use the color image 15 itself as a "position marker" to control the laser 20 and the deflection unit 22.

Thus, after the position of the color image 15 in the processing position of the laser engraving system 19 is known, a portion of the image information of the color image 15 characterizing and / or overwriting the color image 15 is written into the substrate 11 as recognition-relevant features with the aid of the laser. The intensity of the laser beam 23 and thus also of the writing beam 23 'is controlled by the arithmetic and control unit 21 as a function of the impact point of the writing beam 23' on the color image 15, for example with the aid of a shutter unit of the laser 20. The writing of the identification-relevant features in the substrate takes place through the color image 15 through, which is constructed for this purpose from printing inks or inks that either pass through the laser radiation unhindered and thereby, not damaged, or can be specifically removed by the laser radiation.

The identification-relevant features of the original image, that is, for example, the lines of a sketch, can be supplied to the arithmetic and control unit 21 recordable via a data input 25 from a central computer. However, it is also possible with the aid of the image recording device 24 to record the color image 15 applied to the data carrier 10 and to subject the image information thus obtained to a spatial analysis with spatial filtering in order to obtain a component of the image information representing the identification-relevant features. In this case, no additional connection of the laser engraving system 19 to the central computer or a central data memory is required for the additional writing of the identification-relevant features into the substrate 11.

In particular, it is also possible to subject image data recorded pixel by pixel along a picture line directly to a spatial filtering, so as to determine in practice in real time the identification relevant features to be written from the color image 15 itself. This approach has the advantage that the recorded color image data need not be stored as such, whereby additional security in the handling of the data carrier 10 individualizing data is guaranteed against counterfeiting.

If the spatial filtering of the image information is carried out with such a high pass that a pure line drawing is obtained, which is to be displayed without gray levels in a single degree of blackening, this has the advantage that a simple laser can be used without influencing the security against forgery of the image recorded according to the invention can, in which the beam intensity or the intensity of the individual laser beam pulses need not be adjustable.

The inventive method makes it possible to record a brilliant color image in accordance with the high-resolution color image on a data carrier 10 and the counterfeit security thereby produce that additionally recognition-relevant pixels, z. B. a substantially corresponding to the image contours line sketch forgery-proof be inscribed in the substrate. At the same time, the recognizability of images, in particular passport photos, is thereby significantly improved.

Even if it should be possible to remove the color image, yet the black-and-white, with or without gray tones carried out identification-relevant features in the substrate 11 and would significantly affect the application of a new color image, so that the distortion of the image already at the diminished image quality is easily recognizable.

Although the method according to the invention for recording image information on a data carrier 10 has been explained on the basis of a color image 15 shown as a passport photo, it can be applied to all monochrome or multicolor representations. Even gray-tone images can be easily counterfeit-proof recorded on a disk with the inventive method and improve their identifiability.

Claims (16)

1. Method for recording image information on a data carrier (10), in which characteristic facial features are obtained from an original image as features relevant to identification, which characteristic facial features are recorded on the data carrier (10) in a visually perceivable form additionally to a processed or non-processed image corresponding to the original image, wherein the features relevant to identification are superposed on the recorded image with register accuracy,
   characterized in that spatial filters are used for obtaining features relevant to identification.
2. Method according to Claim 1, characterized in that the spatial analysis for obtaining features relevant to identification is applied to one or more colour separations of the original image.
3. Method according to Claim 1 or 2,
   characterized in that a line drawing is obtained from the original image as features relevant to identification, which line drawing is realised in the course of the buffer-storage and/or in the course of the recording of the image on the data carrier (10), in particular in vectorized form.
4. Method according to one of the preceding claims, characterized in that after the image has been recorded, its position on the data carrier (10) itself is acquired and the features relevant to identification are recorded on the data carrier (10) in accordance with the acquired image position.
5. Method according to Claim 4, characterized in that, in order to improve the visibility of the features relevant to identification, the recorded image is the original image whose colour and/or spatial
   information content has been transformed or reduced in a suitable manner.
6. Method according to one of the preceding claims, characterized in that the line drawing is transformed or integrated into a security background (6) of the data carrier (10).
7. Method according to one of the preceding claims, characterized in that the features relevant to identification are recorded on the data carrier (10) with no direct spatial reference to the recorded image.
8. Method according to Claim 7, characterized in that the features relevant to identification are recorded on a special region (4) of the data carrier (10) which has been prepared for the realisation of double- or tilted-image effects.
9. Method according to one of the preceding claims, characterized in that after the image has been recorded, its image information is acquired in order to determine therefrom the features relevant to identification which are to be recorded in addition to the image.
10. Method according to one of the preceding claims, characterized in that the image is applied to an image-carrying area (14, 13'), suitable for the application of information, of the data carrier (10) having a substrate (11), and in that the features relevant to identification are written to the substrate (11) with the aid of radiation.
11. Method according to Claim 10, characterized in that the features relevant to identification are written through the image, which has been recorded on the image-carrying area (14, 13'), to the underlying substrate (11).
12. Method according to Claim 10 or 11, characterized in that the radiation used for recording the features relevant to identification not only causes blackening of the substrate but also alters the previously applied image in a controlled manner, by evaporation or combustion, in order, in this way, to visually emphasize the features relevant to identification.
13. Method according to Claim 10 or 11, characterized in that the features relevant to identification which are recorded under the previously applied image by means of radiation in the substrate (11) are written, without destroying the recorded image, through the latter to the substrate (11).
14. Method according to one of Claims 10 to 13, characterized in that the features relevant to identification are written to the substrate (11) by means of laser radiation, preferably by means of infrared laser radiation.
15. Method according to one of the preceding claims, characterized in that the features relevant to identification are used to produce further effects, such as e.g. water marks or the like.
16. Method according to one of the preceding claims, characterized in that the image-carrying area is produced by coating the substrate (11) provided for the recording of the features relevant to identification.

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