A SYSTEM FOR IMAGE GENERATION WITH SCREEN MEANS AND MEANS FOR IMAGE-WISE MIXING WITH A RECEIVED USER IMAGE

Abstract: An information presentation system has a computer loaded with an application program that feeds screen means for displaying an application generated image. The system has also user input means for supplementing user signalization to the image. In particular, the user input means allow to receive a user image for image-wise mixing into the application-generated image as a mixed image.

Description: A SYSTEM FOR IMAGE GENERATION WITH SCREEN MEANS AND MEANS FOR IMAGE-WISE MIXING WITH A RECEIVED USER IMAGE BACKGROUND OF THE INVENTION The invention relates to a information presentation system as recited in the preamble of Claim 1. Such a system has been disclosed in US Patent 5,448,263. According to the reference, user interaction is effected on a touch sensitive surface, which same surface is being used for thereon projecting the application generated image. Inter alia due to the necessity for such generally large touch sensitive surface, this system is expensive, and furthermore, the range of allowable types of input informations is restricted to those that have been defined for the touch sensitive surface. For example, no colour signals may be inputted and various rendering techniques such as hatching, underlining text and various others are virtually impossible to implement. Also, motion may be inputted only in a very limited and incremental manner. The inventor has recognized a growing need for a low cost-and easy-to-use system for allowing to input a broad gamut of user defined image based signalizations. User functionalities such as offered by a so-called overhead projector would be a boon. Such overhead projector allows in fact the viewing of printed paper, instant writing with a felt pen, and even small objects. In case of a computer-generated image, the instantaneous adding thereto of handwritten notes would be welcomed. SUMMARY TO THE INVENTION In consequence, amongst other things, it is an object of the present invention to enable a user to input an image as such, as represented by user annotations, pictures, features, objects, configurations, and various other images. Now therefore, according to one of its aspects the invention is characterized according to the characterizing part of Claim 1. In particular, the image-wise mixing provides an enormous freedom in the scope of the matter that may be inputted. Further advantageous aspects of the invention are recited in dependent Claims. BRIEF DESCRIPTION OF THE DRAWING These and further aspects and advantages of the invention will be discussed more in detail hereinafter with reference to the disclosure of preferred embodiments, and in particular with reference to the appended Figures that show: Figure 1, an overview of an inventive system; Figure 2, a block diagram of a Mixed Mode Document Camera. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Figure 1 shows an overview of an inventive information presentation system. It is based on computer 64 with keyboard 66 which is loaded with an application program. The application may be presented by memory 62, network 60, or by other means. The application can generate an image that is displayed on screen 76 through projection subsystem 74, that operates in front projection. However, rear projection would be feasible as well in a slightly different configuration. The projection subsystem is fed by image-wise mixer subsystem 68 that is fed by the computer at left. Furthermore, the system has camera 70 that captures a user image, such as one produced independently on sheet 72. The camera-generated image is also sent to mixer subsystem 68, so that the overall image on screen 76 is a composite or mixed one. Camera 70 will allow to take up letters written or printed on sheet 72, small objects, moving items like a human hand during writing, and various other things. Alternatively, item 70 is replaced by a computer-controlled scanner that takes more time to take up all information from sheet 72, so that representing motion is less practical. However, a scanner may generate clearer and/or finer pictures. Figure 2 is a block diagram of a Mixed Mode Document Camera embodiment according to the invention. At left, a VGA or similar composite output signal from the computer is received on interface 20, which has a line duration of about 32 microsecs. The signal inter alia comprises a horizontal sync signal on line 28 and a vertical sync signal on line 24. In block 26, the line frequency is divided by a factor of 2 to get the line time about equal to the standard television line time of some 64 microsecs. Other standards would require other adaptations. The upper part of the arrangement mainly comprises camera module 22, that may be of a commercially available type Philips VCM 3300 as described in the brochure Monochrome Cameras & Modules published by Philips Electronics N.V. Eindhoven, The Netherlands. This module has a resolution of 768*492 pixels. Vertical sync is at 16 millisecs and horizontal at 64 microsecs. Colour modules would operate in a similar manner, which has not been described for brevity. Module 22 serves for preparing the camera image for mixing with the VGA signal. To this effect, camera module 22 receives Horizontal and Vertical Sync signals, as well as detection signals from H/V sync detector 30. If the latter are present indeed, camera synchronization is on external, but otherwise on internal. Camera output is a conventional Color Video Blanking & Sync signal. Horizontal and Vertical Sync signals from the input interface 20 are sent to output VGA interface 32. Block 34 receives the CVBS signal from block 22 and the divided-by-2 Horizontal Sync for in a standard procedure precorrecting against vignetting and other causes of non-uniform image illumination. Next, block 36 is an A/D converter for allowing a more convenient processing of the camera output. Block 38 contains a FIFO storage facility. Other processing mechanisms such as changing the relative size of the camera image, changing the image colour, black-white inverting, filtering text through a text recognition feature, converting to another computer display standard, or converting of the camera image to emulate a computer- generated image may be executed here as well, through providing an appropriate amount of processing facilities. Also, software controlled mixing of driver level images may be done here. By themselves, the necessary facilities are conventional. The output signals from FIFO 38 are reconverted to analog in D/A block 40 and presented to analog mixer module 44 that also comprises a fast switch for effecting changeover between the two image inputs. Block 44 operates under control from block 42 that contains a control circuit and a mode switch. A user may herein select between various modes that will be elucidated hereinafter. The composite mixed signal from block 44 is sent along line bundle 46 to output VGA interface 32, for being displayed on an appropriate projection display device. The above system may have the following extra features. The mixing may as recited be video mixing. A more refined embodiment may have software controlled driver level image mixing, wherein certain properties of the respective images may influence the actual mixing mechanism parameters. A contrast detector may be present for measuring camera contrast. The contrast may be enhanced for the camera image, as well as for the computer generated image. For example in a dark computer image, camera letters may be inverted before mixing to white-on-black. If the computer image is predominantly in a particular color, the camera image may be amended to not include this color. Various operational modes are as follows. In a high quality text mode the computer signal is inverted as soon as the camera views dark text. This allows representing written camera text at high contrast without interfering with VGA-generated contrast. A second mode is graphical that adds VGA signal and camera signal together. Further, this mode allows to vary the respective intensities of the two signals. A preferred packaging combines the camera with the electronic circuitry necessary for effecting the present invention in a Mixed Mode Document Camera. Preferably, the camera has Autocontrast filtering control for allowing the use of various different types of writing pens and or paper. Four main modes are possible: 1. VGA image mode blocks camera image. 2. Text mode displays text in preference over the VGA image, through using the above fast switch. 3. Graphical mode mixes the camera image, for example a photograph, through the VGA image. 4. Camera mode blocks the VGA image and displays only camera image. Further modes are feasible, such as dividing screen area into subscreens, each thereof allowing a respective different mode.

Claims: CLAIMS: 1. An information presentation system based on a computer loaded with an application program that feeds screen means for displaying an application generated image, the system furthermore having secondary user input means for supplementing user signalization to said image, characterized in that said user input means allow to receive a user image for image- wise mixing through mixing means into said application-generated image as a mixed image. 2. A system as claimed in Claim 1, wherein said screen means comprise front or rear projection screen means. 3. A system as claimed in Claim 1, wherein said user input means comprise scanning means, and data processing means for mixing converted signals derived from said scanning means. 4. A system as claimed in Claim 1, wherein said user input means comprise camera means feeding said mixing means. 5. A system as claimed in Claim 1, wherein said user input means allow inputting of moving images. 6. A system as claimed in Claim 1, wherein said mixing means are video mixing means. 7. A system as claimed in Claim 1, wherein said mixing means are software controlled for mixing driver level images. 8. A system as claimed in Claim 1, furthermore comprising synchronizer means for controlling said user input means in a subaltern mode with respect to said computer. 9. A system as claimed in Claim 1, furthermore having image evaluation means for evaluating an actually presented application generated image, and having contrast raising means for raising a contrast therewith through controlling the supplemented image. 10. A system as claimed in Claim 1, and having filter means for filtering the supplemented image before mixing. 11. A system as claimed in Claim 1, and having converting means for converting a camera image to a computer emulating image for user presentation in a camera-only mode.

Inventors: VAN DEN WILDENBERG HENRICUS W, VAN DEN WILDENBERG, HENRICUS, W., J.
Applicants: KONINKL PHILIPS ELECTRONICS NV, PHILIPS SVENSKA AB, KONINKLIJKE PHILIPS ELECTRONICS N.V., PHILIPS AB
Application year: 1999
Main classification: G06F3
IPC codes: G06F3, G09G5