GB2232551A

GB2232551A - Stereoscopic display of stored aerial images with data overlay from graphics generator

Info

Publication number: GB2232551A
Application number: GB9007779A
Authority: GB
Inventors: Michael Richard Heyhoe Page; Alastair Heyhoe Page
Original assignee: ACTION INFORMATION
Current assignee: ACTION INFORMATION
Priority date: 1989-06-06
Filing date: 1990-04-06
Publication date: 1990-12-12
Anticipated expiration: 2010-04-06
Also published as: GB9007779D0; GB2232551B; GB8912998D0

Abstract

Two identical sets of vertical aerial photography frames are stored on video storage mediums such as video discs 4, 5 and a graphics generator 1 stores overlay information, such as the location of key features. Provision is made for displaying any two appropriate aerial photographs for stereoscopic interpretation at a display composed of a pair of high definition colour monitors 6, 7 or as a split screen display so arranged to allow this interpretation. Each set of stored frames corresponds to aerial photographs at different scales, and the graphics generator is controlled so that the graphics overlay is displayed at the same scale as the photographs selected for display. <IMAGE>

Description

DISPLAYING PHOTOGRAPHS The present invention relates to displaying photographs, more particularly aerial photographs.

There are many applications where the display of information in relation to its geographic background is a major requirement, e.g. the updating of records by public utilities (telephones, gas, water, electricity, etc.), display of management information related to geographical areas, emergency command and control systems and many others.

There is an obvious attraction in transferring all this information on to a computer, to give easier retrieval and updating of the records. A system is known in which maps are stored on a video disc and may be selectively displayed on a television monitor under the control of a microcomputer and overlaid with graphic symbols provided from a graphics generator.

According to the present invention, there is provided information display apparatus comprising: dual video reproduction means for producing video signals from a storage medium which stores first and second sets of aerial photographs of different scales recorded on the medium; video display means for receiving said video signals and displaying, as a stereoscopic pair, an aerial photograph from one of the sets and an aerial photograph from the other of the sets; graphic generator means for generating, from overlay information in digital form, video signals representing all or part of said overlay information; and control means including means for storing the overlay information and arranged in operation, in response to information indicative of the geographical area covered by and the relative scale of, the two aerial photographs selected for display, to select from the overlay storage means overlay information in respect of that area and to control the graphic generator means so that the overlay information is displayed on said display means at the same scale as said photographs selected for display.

The video reproduction means may be a pair of video disc players.

Such apparatus may include control means manually operable to cause the video reproduction means to produce video signals representing a stereoscopic pair of photographs geographically adjacent the pair of photographs previously displayed, the overlay control means being responsive thereto to select the corresponding overlay information.

Also, such apparatus may include means which stores alignment information indicating in respect of each photograph of the first set and a corresponding photograph of the second set any offset between the recorded frames and a co-ordinate system to which the digital overlay information is referenced, the graphic generator means being responsive to the said alignment information whereby the overlay information is aligned with the displayed aerial photographs.

Said display means may comprise two video screens or a split video screen.

The present invention will now be described, by way of example, with reference to the accompanying drawings, which: Fig. 1 is a block diagram of an example of a system according to the present invention; and Fig. 2 is a diagram showing how an aerial photograph may be recorded on a video disc.

Referring to Fig. 1, reference numeral 1 designates a microcomputer coupled to a keyboard 2 to which microcomputer is also coupled a mouse", joystick or "trackerball" 3. A pair of video disc players 4 and 5 are controlled by the microcomputer 1 to feed video signals to colour video monitors 6 and 7 respectively.

The discs of video disc players 4 and 5 store analogue versions of identical sets of vertical aerial photography frames of different scales as are used in aerial stereoscopy. Reference numeral 8 designates a text display monochrome video monitor and reference numeral 9 designates a video printer for producing hard copy of what is displayed on monitor 6. Reference numeral 10 designates a screen between monitors 6 and 7 so that the left eye of a viewer can observe only monitor 6 and the right eye can observe only monitor 7, reference numeral 11 designating an optical viewing device for this purpose.

Such a system could be produced for the professional interpretation of maps, for example by land use analysts.

A graphic generator in microcomputer 1 generates, from overlay information in digital form, video signals representing all or part of overlay information, the microcomputer combining these video signals with the video signals from video disc player 4. The microcomputer also provides control means including means which stores the overlay information and is arranged in operation, in response to information indicative of the geographical area covered by and the relative scale of, the two aerial photography frames selected for display, to select from the overlay storage means overlay information in respect of that area and to control the graphic generator so as to display the overlay information at the same scale as the photography frames selected for display.

Also, the microcomputer 1 has control means manually operable to cause the video disc players to produce video signals representing a stereoscopic pair of frames geographically adjacent the pair of frames previously displayed, the overlay control means being responsive thereto to select the corresponding overlay information. Also, the microcomputer 1 stores alignment information indicating, in respect of each pair of frames recorded on the discs, any offset between the recorded frames and a co-ordinate system to which the digital overlay information is referenced, the graphic generator being responsive to the alignment information whereby the overlay information is aligned with the displayed aerial photographs.

In practice, the microcomputer 1 could be provided by an IBM PC AT with the MIC 3500 boards used to mix the output of the graphics generated by an EGA card with the output from video disc player 4, the controlling image overlaid with graphics generated by the software then being fed to monitor 6. The players 4 and 5 could each be a Sony 1600 and the monitors 6 and 7 could each be a colour monitor with fast blanking characteristics, such as a Sony KX 14. The man-machine interface would not be a touchscreen in this case but would consist of both keyboard 2 and mouse, joystick or trackerball 3.

The arrow under the control of this input device would allow the operator to position symbols and to indicate the location on the image which was under assessment.

Monitor 8 is included in the system to allow data concerning the interpretation to be recorded, edited and recalled, as appropriate.

Printer 9 is a facility to capture hard copy of the image on the colour monitor 6 and printer 12 is a facility to capture hard copy of the image on the monitor 8, for inclusion in reports or for subsequent reference. The image on monitor 6 would be supplemented by a daughter board in microcomputer 1 controlling video disc player 5 to present the other image of an appropriate stereoscopic pair on colour monitor 7, placed adjacent monitor 6. This sub-system would have no facility for graphic overlay and would have no print-out facility.

The two monitors 6 and 7 would be mounted at an appropriate distance and height from the operator's position and the optical viewing device 11 provided to ensure that the left eye and the right eye were only able to see their appropriate images, i.e. by virtue of screen 10.

It would be equally sensible to use available electronics, for example the DVA 4000 system from Videologic, to create the two images on the one screen and this could be done by capturing appropriate frames from the one video disc player. This is a more elegant but more expensive solution than that previously described.

2. An aerial photograph is placed on a plotting table 12 with XY movements controlled by a computer 13 so that the photograph can be positioned and then moved under a video camera 14 held by a rostrum 15. The camera could be a SONY DXC-M7 video camera. The output of camera 14 is supplied to a processor 16 which supplies a video disc recorder 17. The former could be a SONY LVS 6000P laser video disc processor and the latter a SONY LVR 6000 laser video disc recorder. The computer control is written in 'C' language and this determines the positioning of the camera over the geographical features of interest and also allows the resultant video disc to be calibrated and scaled to allow the overlaying software to be integrated on completion of the data capture process.

The video disc of video disc player 4 could also store signals representing maps of areas corresponding to at least some of the aerial photography frames. In this case, the arrangement is such that there can be selectively displayed on monitor 6, a map instead of the aerial photography frame which was being displayed on that monitor, on which monitor there may be also displayed overlay information from the graphic generator.

Claims

1. Information display apparatus comprising: dual video reproduction means for producing video signals from a storage medium which stores first and second sets of aerial photographs of different scales recorded on the medium; video display means for receiving said video signals and displaying, as a stereoscopic pair, an aerial photograph from one of the sets and an aerial photograph from the other of the sets; graphic generator means for generating, from overlay information in digital form, video signals representing all or part of said overlay information; and control means including means for storing the overlay information and arranged in operation, in response to information indicative of the geographical area covered by and the relative scale of, the two aerial photographs selected for display, to select from the overlay storage means overlay information in respect of that area and to control the graphic generator means so that the overlay information is displayed on said display means at the same scale as said photographs selected for display.

2. Apparatus according to claim 2, in which the video reproduction means is a pair of video disc players.

3. Apparatus according to claim 1 or 2, including control means manually operable to cause the video reproduction means to produce video signals representing a stereoscopic pair of photographs geographically adjacent the pair of photographs previously displayed, the overlay control means being responsive thereto to select the corresponding overlay information.

4. Apparatus according to any preceding claim, including means which stores alignment information indicating in respect of each photograph of the first set and a corresponding photograph of the second set any offset between them and a co ordinate system to which the digital overlay information is referenced, the graphic generator means being responsive to the said alignment information whereby the overlay information is aligned with the displayed aerial photographs.

5. Apparatus according to any preceding claim wherein said display means comprise two video screens or a split video screen.

6. Information display apparatus, substantially as herein described with reference to the accompanying drawings.