ITBS20110048A1 - METHOD TO ENRICH THE INFORMATION CONTENT OF VIDEOGRAPHIC IMAGES - Google Patents

Description

DESCRIPTION

of the PATENT FOR INDUSTRIAL INVENTION entitled:

â € œMETHOD TO ENRICH THE INFORMATION CONTENT OF

VIDEOGRAPHIC IMAGESâ €

Field of application of the Invention

The present invention generally relates to devices for multiple display of differentiated graphic contents, such as texts, images, videos, and refers in particular to a method for enriching the information content of videographic images in such devices.

The invention can find useful applications in the dissemination to the public of differentiated information contents depending on the installation environment, such as stations, airports, subways, etc., as well as in devices with opposite display directions mounted on mobile vehicles for public transport such as buses, trams, trains, etc. where it is necessary to display signals, such as directional arrows, or, more generally, information such as passengers getting on and off, next stop messages, etc.

More generally still, the invention can find application in all those cases in which a main graphic content must be able to be displayed on multiple devices arranged in different installation situations and which, precisely for this reason, require a differentiated display of information from case to case.

A typical example of such applications can be constituted by two graphic panels with TFT LCD technology mounted with opposite viewing directions (in the so-called â € back-to-backâ € configuration) on board the subway. In this case, the same display image bearing, for example, an arrow to indicate the passengers on the descent side must be able to be turned in the opposite direction in one of the two devices, precisely to indicate a common descent direction.

State of the art

Currently, the reproduction of different graphic contents, images or videos, on as many reproduction devices is carried out using a video transmission channel for each graphic content to be reproduced.

Figure 1 of the drawings in the appendix schematises an example of one of the techniques currently in use for the reproduction of two video contents 1 and 2 on as many, respective display devices 1a, 2a. In particular, this is a system including a graphic processor 3, for example a Dual Output graphic chipset, having two independent integrated video outputs, as commonly occurs in the case of Embedded PCs.

Another typical example of known technique for the reproduction of two video contents 1 and 2 on as many, respective display devices 1a, 2a is illustrated in Figure 2. In this other example a graphic processor 4 is used consisting of one or more several additional graphics cards, each of which manages a single independent video output as often happens in the case of common Desktop PCs.

On the basis of what has been described above, in order to view several different graphic contents within a single visual channel, it is necessary to use some techniques for the treatment of visual contents.

According to the state of the art, different methodologies are known and already widely used for the manipulation and implementation of multiple textual or graphic information contents within a single visual channel, in such a way that it can then be reproduced by one or more playback devices. Some of these methods are listed below.

- Chroma Key: It is one of the techniques used to create the so-called â € œeffects of Keyingâ € through which it is possible to combine two video sources using a particular color, precisely a "key color", to signal to the video mixer which source use at any given time.

In fact, from the main video source, only the areas coinciding with the "key color" are removed (or made â € œtransparentâ €), thus allowing the secondary video source to be displayed in correspondence with them. However, with this technique, a chromatic discrimination of the contents to be displayed is carried out, linked precisely to the â € œkey colorâ € chosen, but it is therefore not possible to fully customize the graphic content created. Furthermore, the two video sources, once blended together into a single final video content, can no longer be reconstructed or discriminated separately.

- Teletext: This is an interactive service used in television which consists of pages of text that can be viewed on the television screen at the user's request and is used to provide users with various types of information.

This information is transmitted cyclically within the video frames, in particular within the vertical blanking interval. This technique, however, provides additional content of a purely textual or very low graphic resolution. It also requires a special decoding device (decoder) capable of detecting and decoding the additional information content. Furthermore, this content does not interact in any way with the images contained within the video frames and, consequently, does not provide any differentiated graphic content in relation to the images displayed.

- Video mixer: Itâ € ™ a device used to switch different video sources on a single output signal and in some cases to mix them together or add special effects, such as adding text or graphics or manipulation the chromatic or structural properties of the image. As previously reported for the Chroma Key, even in this case, once mixed together into a single final video content, the video sources can no longer be reconstructed or discriminated separately. In fact, in order to discriminate the different video sources on the various display devices, it is necessary to have a number of video outputs at least equal to the number of sources, as illustrated in the example represented Figure. 2.

It therefore emerges that in the techniques and methodologies described above, where a mixing of the video sources is carried out, a unidirectional and permanent union is in fact achieved which then does not make it possible to reconstruct or discriminate distinctly of the video sources in order to be then displayed. corresponding to the different playback devices.

Other methodologies currently used and widespread in which two diversified video contents are used, fall under the term of â € œ3D Imagingâ €. In fact, it represents the set of techniques for creating and viewing images, drawings, photographs and films, aimed at transmitting an illusion of three-dimensionality, similar to that generated by the binocular vision of the human visual system, presenting two different images separately respectively to the left and right eye of the viewer.

Given the variety of current implementation techniques of these stereoscopic visualization technologies, it becomes necessary to make some clarifications on some of them, in particular for those referring to dynamic images (video), more pertinent to the discussion than those referring to static images.

- Anaglyph: it consists in discriminating through the use of glasses with complementary filtering, two images (one dedicated to the right eye and the other dedicated to the left eye) previously filtered with two different colors.

- Alternating darkening system: it consists in discriminating two images, one dedicated to the right eye and the other dedicated to the left eye, through glasses equipped with synchronized active shutter glasses, projected in rapid sequence.

- Polarized lens system: it consists in discriminating, by means of orthogonally oriented polarized lenses with respect to each other, two images, one dedicated to the right eye and the other dedicated to the left eye, projected quickly sequence.

- Autostereoscopy or AS-3D: consists of â € œhidingâ € the image dedicated to the other from each eye through the implementation of specific technologies directly on the support (printing on paper or monitor), without requiring the use of other devices. Some implementation technologies of this system are: lenticular network, parallax barrier, lighting and holographic screen. In the case of a video display device, however, the application of autostereoscopic techniques involves, as mentioned, the implementation of special technologies directly on the display medium. Furthermore, the overall image must necessarily have larger dimensions, as it must be made up of several points of view of the â € œoriginalâ € image, observed respectively by the left eye and by the right eye using specific devices in function of the technology implemented. This also implies that the illusion of three-dimensionality is obtained only by observing the device within certain viewing angles.

However, it is evident that the techniques described above involve the use of optical devices, such as complementary filtering glasses or polarized lenses, or opto-electronic such as synchronized active shutters. Furthermore, the alternating dimming system does not provide information content in real time, but discriminates, by means of synchronized active shutters, two images displayed at different instants.

Objective and Summary of the Invention

Starting from these premises, and after having considered in particular some â € œ3D Imagingâ € techniques, the current inventors have instead gone in search of a further technique of visualization of differentiated videographic contents able to allow an effective discrimination of graphic contents. on various reproduction devices, advantageously without having to resort to optical or opto-electronic instruments and without increasing the resources and performance of the graphic processor.

The present invention is the result of such research and aims to provide an innovative method for enriching the information content of videographic images with differentiated graphic contents, more particularly a method for a reconstruction of the aforementioned differentiated images for their viewing on different playback devices.

This objective is achieved, in accordance with the invention, with a method for enriching the information content of videographic images which includes:

the preparation of a main videographic image, the preparation of one or more videographic images bearing the additional information,

a video encoding of the main videographic image added to the additional videographic contents, e

a subsequent video decoding for a reproduction of the additional videographic contents on different display devices discriminately within the same image.

It should be noted, therefore, that the method proposed here is not so much aimed at the implementation of a stereoscopic vision of the image (although it can also be implemented in this context) but, as previously mentioned, at the discrimination of different graphic contents on different display devices. Brief Description of the Drawings

An example of embodiment of the invention will in any case be better illustrated below in the description made with reference to the attached reproductions in which, in addition to Figures 1 and 2 indicative of the state of the art commented above, they are represented in:

Figure 3 a block diagram of the entire process according to the invention;

Figure 4 a block diagram of the video encoding process; Figure 5 a block diagram of the video decoding process; Figure 6 an example of creating a coded image; Figure 7 an example of coding of a single differentiated content in a single 8-bit chromatic channel.

Figure 8 an example of encoding of positional and control information; And

Figure 9 an example of decoding and reconstruction of a single 8-bit chromatic channel.

Detailed description of the Invention

Figure 3 therefore shows a block diagram of the entire process according to which, for example, at least two differentiated video contents 11 and 12 are mixed and encoded in a video encoding system 13, then processed in real time in a video decoding system 14 so as to separate and reconstruct the distinct and independent video information on as many display devices 15 and 16.

Video encoding

As shown in Figure 4, the video encoding in 13 is carried out in the following phases:

- coding of differentiated graphic contents and relative positional and control data on the main image;

- transmission of the encoded image to the playback devices.

Video decoding

As shown in Figure 5, video decoding in 14 is carried out in the following stages:

- decoding of positional and control data from the received encoded video stream;

- transmission to the display devices of the differentiated content in case of correspondence with the relative positional and control data previously decoded or transmission of the original common content (not differentiated).

As highlighted below in detail, the proposed method does not alter either the dimensions in bits or bytes of the main image or its resolution. Consequently, the transmission band necessary to be able to send the image to the display devices also remains unchanged.

The method can be implemented through any data processing device (microprocessor), programmable logic (FPGA, CPLD, etc.) or, more generally, through any digital processing logic circuit.

In particular, the proposed coding envisages the enrichment of the main image with one or more differentiated images and with information relating to the position of these differentiated images and any control information.

The differentiated images are encoded within the main image in the exact position where you want them to be displayed as differentiated content on the different playback devices.

Figure 6 shows an example of creating an encoded image. In the main image, an area is defined, for example, of 250/200 pixels in width and 50/100 pixels in height, inside which, for example, a directional arrow of a given color is displayed (Figure 6, a). A differentiated content is then created having the same size as the defined area, for example a directional arrow of another color in the opposite direction to the previous one (Figure 6, b). At this point, the differentiated content is encoded in the defined area on the main image, thus generating the encoded image to be transmitted (Figure 6, c).

The actual encoding is carried out at the level of each color component constituting the pixel of the main image and of the differentiated contents to be encoded.

Assuming to use images encoded with RGB (Red, Green, Blue) color model at 24 bit depth (8 bit for each color), the pixels defined in the differentiated content area on the encoded image are composed using the 4 most significant bits (MSBs, Most Significant Bits) of each chromatic channel constituting the main image and the 4 most significant bits of each chromatic channel constituting the differentiated content.

The 3 Bytes thus obtained (8 bits for the red color, 8 bits for the green color and 8 bits for the blue color), will thus form each single pixel defined in the differentiated area present in the encoded image.

The pixels that are not part of the areas with differentiated content are instead reported unaltered on the coded image as they are composed in the main image.

The resulting encoded image is then ready to be transmitted to the various graphic reproduction devices.

For indicative purposes, Figure 7 shows an example of coding in which the 4 bits obtained from the main image 5 are positioned in the upper part of the byte constituting the chromatic component of the encoded image, while the 4 bits obtained from the differentiated content they are positioned in the lower part.

It will also be possible to implement other coding combinations of the byte constituting each chromatic component 10 relating to the encoded image, such as the encoding of the 4 bits obtained from the main image in the 4 even positions of the byte of the encoded image, and the coding of the 4 bits obtained from the differentiated content in the remaining 4 odd positions.

Following the coding structure shown in Figure 7, Table 1 shows an example of coding with a single differentiated content of a 24-bit pixel (thus consisting of 8 bits for the red chromatic component, 8 bits for the green one and 8 bit for the blue one), which will constitute the area with differentiated content in the encoded image.

20

Bit position

Color Channel 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 Red 1 1 0 1 0 1 1 0 1 0 0 1 0 0 1 0 1 1 0 1 1 0 0 1 Green 1 1 0 0 1 0 0 1 0 0 1 0 0 1 1 1 1 0 0 0 0 1 0 Blue 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 0 0 1 1 0 1 0 1 0

Main Image Differentiated Content Coded Image Table 1

As previously said, it is possible to encode multiple differentiated contents and encode them in a different way according to the type of images to be used, the needs and the type of application.

The Table shows an example of encoding a single color component (sub-pixel) at 10 bits with two different differentiated contents, using only 2 bits for the encoding of each of them.

Bit position

1

Sub-Pixel 9 8 7 6 5 4 3 2 1 0

0

Sub-pixel Main Image 1 1 0 1 0 1 1 0 1 1 1 Sub-pixel Content

1 1 0 0 1 0 0 1 0 0 1 Differentiated 1

Sub-pixel Content

0 1 1 0 0 1 0 1 1 1 0 Differentiated 2

Sub-Pixel Encoded Image 1 1 0 1 0 1 1 1 1 0 1

Cont. Cont. Main Image

Diff.1 Diff.2 Table 2

As previously expressed, each image (whether dynamic or static) can be enriched with more differentiated contents, and therefore reproduced in a different way on different graphic reproduction devices.

In order to correctly reproduce each differentiated content, it is also necessary to be able to discriminate exactly the areas in which these contents have been inserted. To do this, positional information, and possibly control information, relating precisely to the areas concerning the differentiated contents are also included in the composition of the encoded image.

The encoding of positional information can be carried out by inserting in binary coding the coordinates of the pixels on the graphic matrix corresponding to the two opposite vertices relative to each area within which the differentiated content is encoded. However, it will be possible to use different information to determine each area with differentiated content, such as, for example, a vertex, its location with respect to the area and the dimensions in pixels (width and height) of the area itself.

For example, the coordinates can be defined according to the format â € œline, columnâ € and reported on the matrix of pixels having as origin (0, 0) the first pixel in the upper left, that is the first pixel containing the information of ... ™ image usually transmitted, as shown in Figure 6.

It is preferable to insert this encoding already in the first lines of the encoded image, so as to be able to decode the exact position of the areas with differentiated content even before the content of the image, thus being able to dispose of them during the processing of the same.

Figure 8 shows an example of coding relating to the position of a single area with differentiated content. It is also shown how it is possible to insert a control byte, through which to indicate to the graphic processor during reception, the presence of areas with differentiated content in the transmitted image and, consequently, to activate decoding and € ™ processing of the same.

It is evident that, in the same way, it is possible to enter other additional information (such as an error check on the information received or information for the chromatic alteration of the image) depending on the type of application and of the graphic processing device being received.

In practice, the coding can be implemented on any RGB color component, depending on the number of differentiated coded areas, or possibly on all three color components depending on the number of positional information that determine them.

In the previous example of Figure 8 the encoding can be implemented using the less significant bit (LSB, Less Significant Bit) of the red color component of each pixel that constitutes the image, encoding the entire 40-bit string in the first row (thus using 40 pixels) starting from the source pixel at the top left (0, 0).

As shown in Figure 5, to decode and process the differentiated content areas from the received video stream, it is first of all necessary to correctly decode the positional information and any control information. The decoding of positional and control data is performed upon receiving the real-time encoded video stream. As seen previously, once the desired coding protocol has been established, the receiving graphic processor can simply decode the information necessary both for the discrimination of the differentiated graphic areas and for the display control or any other coded information useful for the specific application.

After decoding and acquiring the position information relating to each area with differentiated content, as well as any control information, the receiving graphic processor can proceed with the processing of the coded image discriminating the display of the differentiated content on the various devices.

By carrying out the procedure described for encoding the differentiated content in an inverse way and, obviously, limited to the areas with differentiated content, it is possible to decode the most significant bits of the main image and the most significant bits relating to the differentiated content for each component of color of each pixel and thus reconstruct the various images.

With reference to the previous example shown in Figure 7, the 4 most significant bits of each chromatic component of the encoded image are used to reconstruct the 4 most significant bits of each chromatic component of the main image, while the 4 least significant bits are used to reconstruct the 4 most significant bits of each chromatic component of the differentiated content. The complete reconstruction of both the main image and the one with differentiated content is performed by reporting also in the lower part the same 4 bits decoded and positioned in the most significant part of the byte. This makes an 8-bit binary approximation of the chromatic level for each color component, as shown in Figure 9.

The reconstruction of the main image and of the images with differentiated content can be carried out, depending on the application and the type of coded image, by means of association tables (Look-up Tables), specific image reconstruction algorithms or preset values.

Claims (9)

â € œMETHOD TO ENRICH THE INFORMATION CONTENT OF VIDEOGRAPHIC IMAGESâ € R I V E N D I C A Z I O N I 1. Method for enriching the information content of videographic images including the steps of: a preparation of a main videographic image, a preparation of one or more videographic images bearing the additional information contents. a video coding of the videographic image added to the additional differentiated videographic contents, e a subsequent video decoding for a reproduction of the additional videographic contents differentiated discriminately within the same main image on different display devices. 2. Method according to claim 1, characterized by the fact of implementing the main videographic image with at least one additional videographic content differentiated in at least one area of a given number of pixels of said main image so as to reproduce the additional videographic content differently within the same main image area on different display devices. Method according to claim 1 or 2, characterized by the fact of mixing and coding in a video coding system the information of at least two differentiated videographic contents, and then processing and separating, in real time, in a video decoding system the information of such differentiated videographic contents in order to reconstruct the differentiated videographic contents in a distinct and independent form on different display devices. 4. Method according to one of the preceding claims, characterized by the fact of defining at least one area of the main image within which to reproduce at least one differentiated videographic content, of encoding in the area defined on the main image differentiated videographic content, and therefore to generate the coded image to be transmitted and displayed differently on different devices. 5. Method according to the preceding claims, characterized by the fact that the video coding system comprises a coding of the differentiated videographic contents and of the relative positional and control data on the main image and also the transmission of the coded image to the reproduction devices of the enriched image. 6. Method according to claim 5, characterized by the fact that the encoding of the positional data can be carried out by inserting in binary coding the coordinates of the pixels on the graphic matrix corresponding as an example to the two opposite vertices relative to each area within which The differentiated content is encoded. 7. Method according to claim 5 or 6 characterized by the fact that the coding can be carried out at the level of each color component constituting the pixel of the main image and of the differentiated video content, and that the pixels defined in the content area differentiated videographic on the coded image can be composed using the most significant bits (MSBs, Most Significant Bits) of each chromatic channel constituting the main image and the most significant bits of each chromatic channel constituting the differentiated videographic content. 8. Method according to claim 7, characterized by the fact that the coding can be carried out on any color component (RGB), depending on the number of differentiated coded areas, and on the number of positional information that determine them, or possibly on all of them three color components. Method according to the preceding claims, characterized in that the video decoding system comprises a decoding of the positional and control data coming from the video encoding, and the transmission of the decoded data to the display devices of the differentiated videographic content in case of correspondence with the relative positional and control data just decoded.