Abstract:
Image answering apparatus comprising: an interface for connecting to a public telephone system; and memory for storing audio and image information received over the public telephone system.

Description:
FIELD OF THE INVENTION 
     This invention relates in general to an image storage system, and relates more particularly to an image answering machine for storing voice and images received over a public telephone system. 
     BACKGROUND OF THE INVENTION 
     Digital cameras have come into wide use for acquiring images of people, scenery, sporting events, etc. The acquired digital images are either stored on removable media (memory card, magnetic disk) which can be used later with a computer or transmitted from the camera directly to a computer. In the case where the user is located near a computer, the images can be transmitted over a dedicated communication link, such as a cable or wireless link. When, however, the user is travelling and is therefore remote from his computer, the digital images can be transmitted form the digital camera to the users computer over the public telephone system. However, digital images from a digital camera or other source cannot be accepted by an individual who does not own a personal computer or who does not want the computer to be left on to receive incoming calls (for example, during a prolonged travel). 
     There is thus a need for a device that is low in cost that can store images transmitted over public telephone systems. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a solution to the problems of the prior art. 
     According to a feature of the present invention, there is provided an image answering apparatus comprising: an interface for connecting to a public telephone system; and memory for storing audio and image information received over the public telephone system. 
     ADVANTAGEOUS EFFECT OF THE INVENTION 
     The invention has the following advantages. 
     1. A low cost machine is provided for storing both images and voice transmitted over a public telephone system. 
     2. A user of a digital camera or other source of digital images can store images sent over a public telephone without owning an expensive personal computer or without having to leave a personal computer on for extended periods while away from home or business. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic view of a system incorporating the present invention. 
     FIG. 2 is a block diagram of an embodiment of the present invention. 
     FIG. 3 is a diagrammatic view of an exemplary file header. 
     FIGS. 4A,  4 B are a flow diagram of the record function of the present invention. 
     FIG. 5 is a flow diagram of the playback function of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In general, the present invention provides a digital or analog answering machine that can accept calls from digital cameras or image sharing devices and can play them back to printers, picture phones or computers. The Image Answering Machine is equipped with the following additional features and processes to make it image compatible: 
     Extra long message tape or memory because images take a lot of memory. 
     Communication protocol that detects an “image data” call and determines available tape before receiving the image. 
     Ability to send the data back out a data port like RS232 or USB. 
     The ability to send the data out of a phone simulator port so it could be compatible with a computer modem. 
     The ability to read an image header and announce the image title in addition to the image data and time (which is an answering machine function, not the image data). 
     The ability (optional) to decode the presence of voice data on the image file (like TIFF) and play that message on command. 
     The ability to play it back into a camera for review either locally or via a call to the device. 
     The ability to decode and display on the answering machine. 
     Referring now to FIG. 1, there is shown a system incorporating the present invention. As shown, an imaging device  10 , such as a digital camera or scanner or other source of digital images, transmits images over a public telephone system  16  (such as the Public Switching Telephone Network, cellular phone network, etc.) to an image answering machine  18  (according to the present invention) having interface  22  (phone jack). The images can also be transmitted over system  16  to personal computer  12  via modem  14 . A telephone  20  can also be connected to machine  18  through interface  22 . 
     FIG. 2 shows in greater detail an embodiment of the image answering machine  18  of the present invention. As shown, machine  18  includes a phone interface  22  for connection to a public telephone system and/or to a telephone, a data access arrangement  24 , a central processing unit  26 , and analog and/or digital storage, such as tape storage  28  for analog data and digital storage  32  for digital data. A motor controller  30  controls tape storage  28 . Central processing unit (CPU)  26  includes DSP (Digital Signal Processor)  27 . Machine  18  also includes analog data bus  40 , printer and peripheral I/O  34 , control panel/display  36 , and control bus  42 . I/O  34  is shown as having USB (Universal Serial Bus) interface  44  and RS- 232  interface  46 . This is the preferred embodiment, but many other communication interfaces are feasible, including firewire, IEEE 1394, and others. 
     Referring now to FIGS. 1,  2 , and  4 , there will be described operation of the present invention in the record function. As shown, image device  10 , such as a digital camera, makes a call to the answering machine  18  via the public phone network  16 . It initiates this call in the normal means by presenting an off hook condition to the phone line, and upon receiving dial tone, transmits DTMF (Dual Tone Multi-Frequency) tones to dial the desired number. The call is routed by the PSTN  16  to the image answering machine  18  via connection to phone jack  22  in the standard way. When the call is received by the image answering machine  18 , the line rings for a presentable number of rings, at which point the image answering machine  18 , presents an off hook condition to the PSTN  16  which completes the connection. The machine  18  plays a prerecorded message and prepares to record a voice message. The DSP part  27  of the CPU  26  samples the incoming data on line  40  and checks for 8 to 16 Hz modulation, characteristic of human speech. If no speech is detected the image answering machine  18  emits a unique audio tone so that the transmitting device  10  knows the image answering machine  18  is on the line. The transmitting device  10  then returns a unique tone indicating that an image device  10  in is on the line. The imaging answering machine  18  ceases its initial tone and prepares to receive digital (image) data. 
     In the receive image data mode, the machine  18  records the audible frequency shift or AM modulated signal. In the answering machine  18 , this data is either stored on analog tape  28  in its original form, or sampled by the DSP  27  and converted to a digital format for storage in the digital memory  32 . In the digital storage mode, the image answering machine  18  can look at the digital data and determine from the file header FIG. 3, how much data is required to store the transmission. The image answering machine  18  must keep track of tape time to make sure it can record an entire image. If there is insufficient memory to store an image, a tone is returned to the calling imaging device and the device can try again with a different size image. This negotiation can happen several times before the answering machine or camera gives up. Using a tone method, makes the transmitting device decide if it wants to try again without engaging in a more complex digital protocol. If the analog method is used, the system may not know what size image(s) is(are) coming. 
     It is possible to digitize the voice data and store it with image data in the digital storage section  32 . Digital answering machines  18  do exactly that with voice (only) today. In this case, the voice and image files have to be identified by file type in the file header FIG.  3 . In digital cameras  10  (FIG. 1) with voice recording capability, it is possible to store a voice clip as a digital part of the image file. EXIFF or TIFF is a common file format for storing this type of data as tagged data. The image answering machine  18  can have the ability to decode the voice tag and use the DSP  7  to regenerate the voice message. That message can then be added to the answering machine  18  before the image so the photographer can instruct the receiver, label the data with a voice label, or record a voice command used by a device which could be connected to the image answering machine by its peripheral port  34  (FIG.  2 ). 
     If the data is stored in analog form, it can be marked as digital or voice by placing different tones at the beginning and end of each segment, or by detecting the syllabic rate of the voice segments. 
     If a voice call was made, the lack of tones and detection of syllabic rate (the sub 20 Hz modulation of human speech) voice energy, the machine  18  acts as a normal voice answering machine. 
     Once the image(s) data is(are) captured in the machine  18  as analog tones, the system can send back a verification or status signal that can be used to notify the user via the Control Panel/Display  36 . The connection can be dropped by presenting a high impedance “on hook” condition to the phone line. The camera preferences can be preset to erase any successfully transmitted image. 
     The next part of this scenario is playing the data/message back in a usable manner (see FIGS. 1,  2 ,  5 ). The image answering machine  18  needs to be able to tell the difference between image and voice data when they are recorded on the same media. If the data were recorded in analog storage  28 , the CPU  26  would first look to the Control Panel/Display  36  to determine if the user wanted to play back voice messages or images. The tape of storage  28  would rewind and either look for tones preceding the segments and play the desired types, and fast forward the other types of segments, or perform a syllabic rate detection on the segments and then decide whether to play the sound or fast forward. A Fourier Transform may be required to preserve the frequency content of the tape segments so that the syllabic rate can be detected in the presence of high speed forward or playback. Voice tags associated with the image can also be played back as a voice message to identify an image, or instruct the answering machine owner what to do with the file. The image answering machine  18  should be capable of redirecting the analog image data (in analog form) out as tones to drive another modem&#39;s input, or decoded, digitize and stored on data disk, printer or viewed on a picture phone. 
     If stored in digital format, the image answering machine will have to decode digital files to determine the type of file. If the file is a voice file, it will be read back into the CPU and played out as analog from the DSP section. 
     The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. 
     PARTS LIST 
     digital camera 
     personal computer (PC) 
     modem 
     public switched telephone network 
     image answering machine 
     telephone 
     interface to telephone network (RJ- 11  modular jack) 
     data access arrangement 
     central processor (CPU) with digital signal processing (DSP) 
     DSP (Digital Signal Processor) 
     tape storage device—i.e., cassette tape 
     motor controller 
     digital storage device—i.e., solid state memory 
     printer and peripheral input and output interface 
     control panel and display 
     interface control lines 
     analog data signal line 
     control bus 
     universal serial bus port 
     serial bus port