WO1997031486A1

WO1997031486A1 - Device and method for displaying images on a video-wall built up of one or more display screens

Info

Publication number: WO1997031486A1
Application number: PCT/NL1997/000073
Authority: WO
Inventors: Jan Johannes Swager
Original assignee: Jan Johannes Swager
Priority date: 1996-02-20
Filing date: 1997-02-19
Publication date: 1997-08-28
Also published as: NL1002395C2

Abstract

What is disclosed is a device and a method for displaying images on a video-wall built up of one or more display screens, on which a main image or background image is displayed together with at least one insert image, in such a manner that the circumference of said at least one insert image does not coincide, at least partially so, with the outer circumference of one or more of said display screens. The processing of the video signals in the device takes place on a real-time basis, and the positions and/or dimensions of the various insert images can be adjusted as desired, possibly continuously so.

Description

DEVICE AMD METHOD FOR DISPLAYING IMAGES ON A VIDEO-WALL BUILT UP OF ONE OR MORE DISPLAY SCREENS

The present invention relates to a device and a method for displaying images on a video-wall built up of one or more display screens.

A device and a method of this kind for displaying images on a video-wall built up of one or more display screens, on which a main image or background image is displayed together with at least one insert image in such a manner that the circumference of said at least one insert image coincides with the outer circumference of one or more of said display screens is generally known.

The drawback of such known devices and methods is that the flexibility with regard to the displaying of one or more insert images on a desired position on the main image or background image is not quite satisfactory.

The object of the present invention is to provide a device and a method for displaying images on a video-wall built up of one or more display screens, whereby the system exhibits a greater degree of flexibility, in particular with regard to the delimitation, the position and the dimensions of the insert images to be displayed on the main image or background image.

In order to accomplish that objective the device according to the invention is characterized in that the device comprises several inputs, which can each be connected to a source of video images, such as a video recorder, a video camera, a cable network and the like, whereby each input is coupled to memory means, possibly via an analog-digital converter insofar as said source is an analog source, which memory means include a main image memory which contains the pixels of the video signal from the selected source, which can be displayed on the video-wall as the main image, and which include a number of sub-memories to be filled with pixels of the video signal from the various sources equal to the number of insert images that can be displayed on the display screens, and whereby the device comprises controllable switching means for each display screen, which are coupled on the one hand to said memory means and on the other hand to the respective display screen, and which, when the main image is being displayed on a display screen together with at least part of at least one insert image, are controlled to switch alternately to the main image memory and to at least one of the submemories containing the pixels of the insert image in question.

The advantage of the device according to the invention is that the range of applications of video-walls has been enlarged, since it has now become possible to use these walls for applications where it was previously undesirable but unavoidable that the insert images covered parts of the main image which were considered to be essential. Think in this context in particular of the displaying in monitoring or control rooms of a complex to be monitored, such as a factory complex, whereby certain processes, chemical processes, for example, or reactors must be monitored, or of the monitoring of a road or railway junction or the When in accordance with another embodiment of the device according to the invention a display screen memory containing all the pixels of the image to be displayed on a respective display screen is connected between said switching means and each display screen, further technical possibilities are created for transmitting images to the video-wall, virtually on a real-time basis, if desired, and displaying said images at a desired point in time.

In accordance with another embodiment of the device according to the invention it is possible to vary the position of the insert images on the video-wall as desired by influencing the point in time at which switching from the main image memory to one or more submemories takes place, and furthermore it is possible, by using an interpolating divider, which is usually provided with a control input, to influence not only the position but also the dimensions of the insert image in question, irrespective of the fact whether the insert image is fully displayed on one display screen and within the outer circumference thereof, or whether the boundary or boundaries with one or more display screens is (are) crossed thereby.

The present invention furthermore relates to a method for displaying images on a video-wall built up of one or more display screens, on which a main image or background image is displayed together with at least one insert image, in such a manner that the circumference of said at least one insert image does not coincide, at least partially so, with the outer circumference of one or more of said display screens . In a preferred embodiment of the method according to the invention the position and/or the dimensions of said at least one insert image can be freely adjusted, in particular continuously so, and according to another preferred embodiment the processing of the video signals takes place on a real-time basis, which is advantageous for the aforesaid monitoring functions.

The present invention will now be explained in more detail with reference to the accompanying Figure, by means of which preferred embodiments of the device and the method for displaying images on a wall built up of several display screens will be explained.

The Figure diagrammatically shows a device 1 for displaying images a,b,c,d,e on a wall 3 built up of several display screens 2-1, 2-2, 2-3 and 3-4. Wall 3 may also comprise more display screens 2, of course. The device 1 comprises inputs, 4-1, 4-2, ... 4-n for connecting sources 5-1, 5-2, ... 5-n which deliver analog or digital video signals, such as a video recorder, a video camera, a network, such as a cable network and similar sources. Insofar as sources 5 deliver analog signals, device 1 is provided with analog- digital converter connected to inputs 4, two of which are shown in the Figure, namely 6-1 and 6-n. Device 1 includes memory means 7 coupled to the inputs 4, in which one or more of the video images from said sources 5, that is, the respective pixels, are stored in memories 8-1, 8-2 ... 8-n. One of said memories, memory 8-n, for example, is the main image memory, because the pixels momentaneously stored therein are displayed as the main image or background image

On eαCπ O f tne dl Spi άy SCi ecnS . — x. , . . . <- - . i. lie υ Lliei memories 8-1, 8-2 are called the sub emories, because the pixels stored in said memories are intended for displaying the smaller images, the sub-images or insert images a,b,c,d,e. In addition to that device 1 comprises switching means 9-1, 9-2, ... 9-n connected to memory means 7. Switching means 9 each comprise a separate control input 10-1, 10-2, ... 10-n, which control inputs are each connected to a (usually processor-controlled) control unit 11. Said processor-controlled control unit will generally comprise processors which operate in parallel, in order to enable the switching means 9 to switch over from main image memory 8-n to one or more of the submemories 8-1, 8-2, and vice versa, within one line period of a display screen 2. When image a is identified with source 5-1 and image b is identified with source 5-2, only main image memory 8-n will be read first, while the first part of the image is being written on display screen 2-1, whereby a first part of the pixels of a line L to be written to display screen 2-1 will come from main image memory 8-n after a number of lines of the main image have been written. Then the respective line portion is read from submemory 8-1 during the same line L for building up image a, followed by the reading of main image memory 8-n during line L. Said switching during a line period, in this case by switching means 9-1, takes place very quickly under the control of control unit 11. After the contents of memories 8-1 and 8-n, among which image a, have thus been alternately read and displayed, the first line is written at some point, in which line a switch-over is made to the temporary reading of a part of image b as stored in submemory 8-2 after memory 8-n has been read. The image is further displayed in display screen 2-1, in a manner which will not be explained in more detail, whereby the respective images together with the lurcher insert images or parts thereof appear on display screens 2-2, 2-3 and 2-4 simultaneously therewith. In order to enable reading of the memories 8-1 ... 8-n each of said memories will be provided with associated control signal inputs 12-1, 12-2 ... 12-n, which are connected to control unit 11. In order to slightly lessen the requirements that are made in particular of the switching means 9 and of the hardware, firmware or software in control unit 11, it may be desirable to assign a display screen memory 13-1, 13-2 ... 13-n to each display screen 2, so as to obtain increased flexibility. Although this will slightly increase the time delay between the presenting of the video signals to the input 4 and the displaying of said signals on wall 3, these delays are so short that it is still possible to say that the processing of the aforesaid video signals virtually takes place on a real-time basis. In that case the operation of this embodiment is such that first, usually simultaneously, the display screen memories 13-1 ... 13-n are filled, and that said memories are read, possibly in a next cycle, with their contents being supplied to the various display screens 2-1, 2-2 ... 2-n. Insofar as the controlling of said display screens must take place on the basis of analog signals, D/A converters 14-1, 14-2 ... 14-n are provided. Wall 3 may comprise display or projection screens which are generally known, and which are usually controlled in a known "interlaced" manner, whereby an image is written as two frames, but this may also take place in a "non-interlaced" manner, which is known per se. It does not make a difference whether 50 Hz display screens or 100 Hz display screens, which may or may not have a high resolution, are used. Furthermore the method is not dependent on the type of video standard that is used, such as for example PAL, NI .C, SECAM and the like. The physically limiting factor will usually be the reading and processing times that are required anu Lue uecsbsdiy processing and control speed in control unit 11. In connection with the necessary control and timing functions control unit 11 will also be connected to control inputs 15 (only diagrammatically indicated) of display screen memories 13-1, 13-2 ... 13-n. The embodiment of the device 1 shown in the Figure includes interpolating dividers 16-1, 16-2 ... 16-n, which are shown in memory means 7 and which are connected to the respective memories 8-1, 8-2 ... 8-n, which dividers are each provided with respective control inputs 17-1, 17-2 ... 17-n connected to control unit 11. The dividers 16 function to record the dimensions of the insert images a,b,c,d,e, whereby the dividend of the dividers 16 and therewith the dimensions of the aforesaid insert images can be controlled by supplying appropriate signals to control inputs 17. In the illustrated embodiment respective auxiliary memories 18-1, 18-2 ... 18-n are shown behind the respective dividers 16, which are each provided with respective control inputs 19- 1, 19-2 ... 19-n connected to control unit 11. This to make it possible to preset the memories 18. The insert images a ... e may be freely positioned as desired within the circumference 20 of one or more of the display screens 2. More in particular it is possible, as is shown with regard to insert image b, to have one or more of the insert images intersect one or more of the circumferences 20 between the various display screens 2-1 ... 2-n. Furthermore it is possible to display an insert image partially. The adjusting of the brightness, contrast and colour takes place by supplying appropriate control signals to the control signal inputs 12-1, 12-2 ... 12-n.

Claims

1. A device for displaying images on a video-wall built up of one or more display screens, which device comprises several inputs, which can each be connected to a source of video images, such as a video recorder, a video camera, a cable network and the like, whereby each input is coupled to memory means, possibly via an analog-digital converter insofar as said source is an analog source, which memory means include a main image memory which contains the pixels of the video signal from the selected source, which can be displayed on the video-wall as the main image, and which include a number of sub-memories to be filled with pixels of the video signal from the various sources equal to the number of insert images that can be displayed on the display screens, and whereby the device comprises controllable switching means for each display screen, which are coupled on the one hand to said memory means and on the other hand to the respective display screen, and which, when the main image is being displayed on a display screen together with at least part of at least one insert image, are controlled to switch alternately to the main image memory and to at least one of the submemories containing the pixels of the insert image in question.

2. A device according to claim 1, where: the device includes a display screen memory assc ated with each display screen, which is connected between said switching means and the respective display screen and which contains all the pixels of the image to be displayed on the respective display screen.

3. A device according to claim 1 or 2, wherein the device includes a control unit connected to the control inputs of said switching means for influencing the position of the insert images on the video-wall by influencing the point in time at which switching of said switching means takes place.

4. A device according to any one of the claims 1 - 3, wherein said memory means include an interpolating divider connected between the respective input and a respective submemory.

5. A device according to any one of the claims 1 - 4, wherein said divider includes a dividend control input connected to said control unit for controlling the dimensions of the respective insert image by adjusting the dividend of the divider.

6. A device according to any one of the claims 4 or 5, wherein said memory means include an auxiliary memory connected between said switching means and said divider.

7. A device according to any one of the claims 1 - 6, wherein each display screen is provided with an input, to which a digital-analog converter coupled to said switching means is connected.

8. A method for displaying images on a video-wall built up of one or more display screens, on which a main image or background image is displayed together with

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circumference of said at least one insert image does not coincide, at least partially so, with the outer circumference of one or more of said display screens.

9. A method according to claim 8, wherein the position and/or the dimensions of said at least one insert image can be adjusted, in particular continuously so.

10. A method according to claim 8 or 9, wherein the processing of the video signals takes place on a real-time basis.