GB2101446A - Apparatus for producing a stereoscopic image - Google Patents

Abstract

The apparatus includes a camera, such as a thermal imaging camera, which in use moves over an object to be imaged and which supplies image information directly to a first monitor (M1) and with a time delay to a second monitor (M2) to produce a stereoscopic image. The time delay is provided by a two portion memory (SP1, SP2) arranged so that while one portion is being read out the other portion is being written in. The apparatus may provide moving or still sterescopic images. In the still model of reproduction, an image memory (ST) is connected to the input of monitor (M1). <IMAGE>

Description

SPECIFICATION Apparatus for producing a stereoscopic image The present invention relates to apparatus for producing a stereoscopic image on a stereoscopic viewing unit.

It is known in air photogrammetry to take pictures in quick sequence of an object as a camera moves over the object. By overlapping the images and viewing two consecutive images with a stereoscopic magnifying lens, the overlapping images appear to the viewer in three dimensions.

It is an aim of the invention to provide apparatus for producing three dimensional moving or still stereoscopic images in real time.

According to the present invention, there is provided apparatus for producing a stereoscopic image on a stereoscopic viewing unit, the apparatus including a camera which in use moves over an object to be imaged and which supplies image information directly to a first monitor and with a time delay to a second monitor to produce a stereoscopic image.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawing which is a diagrammatic view of stereoscopic image producing apparatus according to the present invention.

Referring to the drawing, the apparatus includes a thermal-imaging camera FLIR (FLIR=forward looking infrared) mounted on a movable carrier. This movable carrier may be an airplane or a land vehicle. The thermal imaging camera FLIR is a TV compatible device, the image information of which may be displayed directly on a TV-monitor. In the present embodiment the thermal-imaging camera FLIR is connected to a transmitter S arranged on the carrier. The signals transmitted from the transmitter S are received by a receiver E in a ground station. The received signals are applied by means of a closed isolating switch S3 and one branch of a changeover switch S5 directly to a first monitor M1 of a stereoscopic viewing unit BE.Furthermore the received signals are applied by means of a second closed isolating switch S4 to a scratch pad memory SP. The scratch pad memory SP comprises two memory portions Sup 1 and SP2 which may be connected alternately to the receiving unit E by means of a changeover switch S1.A further changeover switch S2 connects alternately both memory portions SP1 and SP2 to the second monitor M2 of the stereoscopic viewing unit BE.

Both changeover switches S1 and S2 are countercurrently actuated, this means that the changeover switch S2 connects the memory portion SP2 to the second monitor M2 while the changeover switch S1 connects the receiving unit E to the memory portion Sup 1. On changeover, the switch S1 connects the receiving unit E to the second memory portion SP2 and the switch S2 connects the first memory portion SP1 to the second monitor M2. The first monitor M1 is normally connected to the receiving unit E.The rate with which the changeover switches S1 and S2 are actuated depends on the velocity of the carrier of the thermal-imaging camera FLIR relative to the object and on the distance of the thermal-imaging camera from the object from which a picture is to be taken.

With the apparatus just described, it is possible to view movable images on the stereoscopic viewing unit BE. On the first monitor M1 the image always appears just taken by the thermalimaging camera FLIR, and on the second monitor M2 an image is displayed which has been taken in advance. By means of the scratch pad memory SP divided into two portions and by means of connecting of those memory portions via changeover switches S1 and S2 to the thermalimaging camera and to the second monitor, a certain delayed time is provided for the image displayed on the second monitor M2 so that both images displayed on the monitors are taken under different angles and are partly overlapping.

The apparatus may also be used for taking and viewing still stereoscopic images. In this case, the changeover switch S5 takes the position shown in dashed lines so that the receiving unit E is connected to the first monitor M1 via an image memory ST. The isolating switch S3 assumes for a short time the shown position in order to write a complete image into the image memory ST while the isolating switch S4 at this moment is in an open position. Following this, the isolating switch S3 is opened and the isolating switch S4 is closed in order to write the image information into the scratch pad memory SP which is received by the receiving unit E under a different taking angle. It doesn't matter which memory portion SP1 or SP2 is used for writing in the time-delayed next image.

The changeover switch S2 only has to be actuated to connect the second monitor M2 to that image portion which contains the stored image. By means of displaying both images stored in the image memory ST and in the scratch pad memory SP on the monitors M1 and M2, it is possible to view a still image three-dimensionally since both images have been taken under different taking angles due to the changed position of the thermal-imaging camera FLIR between image takings.

The above described apparatus provides the advantage that no storage means in form of films is needed on the carrier of the camera. For instance the images are wireless transmitted and may be viewed at the moment they are produced.

If the carrier of the camera is for instance a reconnaissance airplane, then the taken pictures are not lost if the airplane does not return. All facilities for storing and evaluating of the images are arranged on the ground. The apparatus is also arranged in such a manner that the stereoscopic images may be also produced with a single camera having a single view if the images are taken continuously.

Claims (8)

Claims

1. Apparatus for producing a stereoscopic image on a stereoscopic viewing unit, the apparatus including a camera which is use moves over an object to be imaged and which supplies image information directly to a first monitor and with a time delay to a second monitor to produce a stereoscopic image.

2. The apparatus of Claim 1 wherein the means for producing a time delay includes a scratch pad memory located in the information line between the camera and the second monitor, a first changeover switch alternately connecting the camera to one or other of two portions of the memory, and a second changeover switch selectively connecting the second monitor to one or other of the memory portions.

3. The apparatus of Claim 2 wherein the switches are countercurrently actuated, one memory portion being connected to the camera while the other memory portion is connected to the second monitor and vice versa.

4. The apparatus of Claim 2 or 3, wherein the switching rates of both switches is dependant in use upon the velocity of the camera over the object and the distance of the camera from the object.

5. The apparatus of any one of the preceding claims, including an image memory located in the information line between the camera and the first monitor.

6. The apparatus of Claim 5 including an isolating switch located between the camera and the or each memory.

7. The apparatus of any one of Claims 1 to 6, wherein the camera is of the thermal imaging type.

8. Apparatus for producing a stereoscopic image, substantially as herein described with reference to the accompanying drawing.