Abstract:
A device and method allows a user to create a mark corresponding to a moment in time of a captured recording to provide later viewing of a portion of the recording corresponding to the moments in time.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a U.S. Continuation application of co-pending U.S. patent application Ser. No. 14/562,033, entitled “RECORDER AND METHOD FOR RETROSPECTIVE CAPTURE,” filed Dec. 5, 2014 (docket no. 2581-001-05). Co-pending U.S. Continuation application Ser. No. 14/562,033 is a continuation application of U.S. patent application Ser. No. 12/554,656, entitled “RECORDER WITH RETROSPECTIVE CAPTURE,” filed Sep. 4, 2009, now U.S. Pat. No. 8,942,533, issued Jan. 27, 2015 (docket no. 2581-001-03). U.S. Continuation application Ser. No. 12/554,656 claims priority benefit and is a continuation of International Patent Application No. PCT/US2008/003174, entitled “RECORDER WITH RETROSPECTIVE CAPTURE,” filed Mar. 7, 2008 (docket no. 2581-001-04). International Patent Application No. PCT/US2008/003174 claims priority from U.S. Provisional Application No. 60/905,746, entitled “RECORDER WITH RETROSPECTIVE CAPTURE,” filed Mar. 7, 2007 (docket no. 2581-001-02). Co-pending U.S. Continuation application Ser. No. 14/562,033, U.S. Continuation application Ser. No. 12/554,656, International Patent Application No. PCT/US2008/003174, and U.S. Provisional Patent Application No. 60/905,746 are each, to the extent not inconsistent with the disclosure herein, incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    In the use of conventional digital still cameras, conventional video cameras, and conventional sound recorders, the user may be disappointed because they fail to activate the shutter or record command button just prior to or substantially simultaneously with a scene, utterance, or other real time event desired to be recorded. This disappointment may arise because the user does not anticipate the real time event prior to its occurrence or is otherwise distracted and does not press the shutter or record button in time to record the event. 
         [0003]    In other cases where recording is substantially continuous, the resultant recording is so voluminous as to defy a cursory attempt to find the portion of the recording corresponding to a real time event at a subsequent viewing, listening or editing session. Instead, the user must search, frequently rather laboriously, to find the fleeting event in the voluminous entirety of the recording. 
         [0004]    In still other cases, even when a real time event is captured, a recording of events leading up to the real time event is not captured, and thus context corresponding to the captured scene, utterance, or other real time event may be lost. 
       SUMMARY 
       [0005]    In a first embodiment according to the invention, a recording apparatus captures a signal and sends it to a memory, such as a first-in-first-out (FIFO) memory, cache or storage device that provisionally captures a real time event. Data corresponding to signals that are sent to the provisional capture memory, also referred to as provisional data, eventually overflows and is discarded unless a shutter or record command, also referred to as a trigger signal, is received. The trigger signal causes the provisional data to be retained, for example by transferring the provisional data to non-volatile memory or storage, or by retaining the provisional data in the provisional capture memory. 
         [0006]    A user of the recording apparatus may thus capture records of events that happened prior to triggering capture. 
         [0007]    According to some embodiments, the provisional data will continue to be transferred to non-volatile memory or storage or continue to be retained in the provisional capture memory until a timeout is encountered or until the user enables a second trigger event. The timeout or second trigger event may toggle the apparatus back to the provisional capture mode, also referred to as the overflow mode. 
         [0008]    According to another embodiment, a recording apparatus captures an event as a signal and transfers it to storage or non-volatile memory for retention. A trigger signal may be received to mark a particular portion of the recorded signal. The trigger events may be logged in a variety of ways, including but not limited to steganographic insertion into data corresponding to the signal, recording into a controller track, recording into a look-up table (LUT), recording into the data as a visible or audible mark, etc. 
         [0009]    Various forms of recording devices may be used, including but not limited to a digital still camera, a video recorder, an audio recorder, etc. 
         [0010]    According to one embodiment, the recording device is a camera mounted on the user. Such a camera may be bore-sighted with the user&#39;s field of view to record events in the direction of the user&#39;s gaze. A bore-sighted camera may capture signals as video, as a series of still images, or both. A bore-sighted camera may further capture audio. 
         [0011]    According to another embodiment, the recording device is a video or still camera that is not bore-sighted. Such a device may be aimed by a user or mounted remotely to capture a desired field-of-view. 
         [0012]    According to another embodiment, the recording device is an audio recorder. The retrospective triggering of the audio recorder may be used to mark important portions of a recording to facilitate later search and/or parsing of the recorded signal. 
         [0013]    Various trigger apparatuses may be used according to embodiments. For example, a user may select a trigger event by pressing a button, uttering a phrase, making a movement, blowing a puff of air, creating an audio click, creating a signal continuity or discontinuity, or other triggering methods as are known to the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a block diagram of a retrospective recorder, according to an embodiment. 
           [0015]      FIG. 2  is a block diagram of a retrospective recorder, according to another embodiment. 
           [0016]      FIG. 3  is a block diagram of a retrospective recorder having local memory and an interface to remote image storage, according to an embodiment. 
           [0017]      FIG. 4  is a diagram of a network equipped to receive an image from a retrospective capture device, according to an embodiment. 
           [0018]      FIG. 5  is a block diagram of a retrospective recorder having an integrated memory, according to an embodiment. 
           [0019]      FIG. 6  is a flowchart illustrating logic for retrospectively recording according to an exemplary embodiment. 
           [0020]      FIG. 7  is a diagram illustrating a head-mounted camera configured for retrospective recording, according to an embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. Other embodiments may be used and/or and other changes may be made without departing from the spirit or scope of the disclosure. 
         [0022]    A numbering convention to facilitate easy understanding by the reader is used herein. Figures are numbered in conventional consecutive order. Specific features are generally indexed consecutively using three or four digit numbers in the order described. The first one or two digits correspond to the figure number in which the feature is first described. Features having similar functionality generally retain their originally assigned number throughout, even though their physical or logical appearance may vary considerably from figure to figure. 
         [0023]    As used herein, the terms image, recorder, and image signal may refer respectively to various observable phenomena, devices or transducers for capturing such phenomena, and signals output by such capture apparatuses or devices corresponding to the captured phenomena. For example, in an illustrative embodiment, an image may include a visible field-of-view, a corresponding recorder may include a digital camera, and the corresponding image signal may include an electrical signal carrying the captured data, such as a serial or parallel sequence of voltage or current transitions communicated from the digital camera to a buffer memory or a storage apparatus. The image may be still or video and/or may include audio. According to another illustrative embodiment, the image may be purely audio with the recorder being a microphone and the image signal being, for example, an electrical representation of the microphone output. To facilitate ease of understanding the term “image” may be used as shorthand to indicate both an original real-time observed phenomenon and an electrical signal or data representative of the observed phenomenon. 
         [0024]    As used herein, the term “permanent” is used not only to denote a substantially irreversible action, such as recording an image onto a writable optical disc, but also to denote an action that is permanent in a relative sense, such as recording an image into an area of persistent random-access memory (RAM), recording onto flash memory, writing to rotating magnetic memory, etc. Thus, references to “storage” may be taken to include both conventional storage apparatuses and media such as a hard drive, and to functionally persistent memory such as, for example, a volatile memory device that is refreshed to keep the image in memory for more than a relatively transient duration. 
         [0025]    Referring now to  FIG. 1 , an embodiment of a retrospective recorder  102  is shown in block diagram form. A capture apparatus  104 , here illustrated as a digital camera or video recorder, may be operable to output an image signal representative of a captured image to a provisional memory  108  via a data channel  106 . For example, the image signal may include a raw or compressed stream of video frames, such as in AVI video envelopes. According to an embodiment, the image data may be loaded into the memory  108  as a sequence of linked groups, each group including a reference frame and a header formatted for playback starting from the present group. According to an embodiment, the memory  108  may be configured as a first-in-first-out (FIFO) buffer memory configured to overflow the oldest group for each new group received. The memory  108  may be configured to substantially continuously accept image signals from the image capture apparatus  104 . 
         [0026]    The data channel  106  may be considered to transmit “provisional” images from the image capture apparatus  104 . Similarly, the memory circuit  108  may be considered to include “provisional memory” configured to temporarily hold provisional image data corresponding to provisionally captured video images. According to embodiments, the provisional memory  108  may include a first-in-first-out (FIFO) memory configured to overflow the oldest data or a circular buffer configured to overwrite the oldest data, for example. 
         [0027]    For the example of  FIG. 1 , capture apparatus  104  is shown as a digital camera that includes a lens  116 , an aperture  118 , and a light sensor array  120 , all held in alignment by housing  122 . As may be seen, such an apparatus may include a conventional digital still or digital video image sensor, and may be constructed according to a range of architectures. 
         [0028]    When provisional capture is initiated, an image signal begins to be transmitted from the capture device  104  over signal line, node, or terminal  106  to memory circuitry  108 . As time progresses, memory  108  fills up and the first-captured image is shifted out of the memory  108  through node or terminal  110  and is discarded. Alternatively, the newest provisionally captured image may overwrite the oldest provisionally captured image. 
         [0029]    The data capacity of, and hence the amount of time for which provisional images are temporarily held in memory  108  may be determined according to application requirements, recorder cost and size constraints, power consumption, etc. For the case of a series of discrete images, the data capacity of memory  108  affects the number of discrete images that may be temporarily held. According to some embodiments, the provisional memory  108  capacity may be dynamically allocated according to user preferences, image attributes, or other operational considerations. 
         [0030]    Furthermore, the rate of provisional image capture performed by the capture apparatus  104  and the quality of the provisional images captured by the capture apparatus  104  may be dynamically determined according to user preferences, image attributes, sensed values (e.g. acceleration, finger pressure, etc.), or other operational considerations. 
         [0031]    According to an embodiment, at least a portion of the image capture apparatus  102  including the image sensor  120 , the image signal line, node, or terminal  106 , and the provisional memory circuitry  108  may be integrated into a module  124 , such as an integrated circuit. An integrated embodiment, which may optionally include processing logic such as image compression hardware (not shown) and local control logic such as a state machine (not shown), may be advantageous with respect to size, power consumption, cost, etc. and may allow the apparatus  104  to remain in a provisional capture state for a relatively extended period of time with minimal battery requirements. According to an embodiment, an apparatus operable to draw power from the environment, such as a photovoltaic apparatus, heat pump, electromechanical inductive charger, etc. (not shown) may be coupled to a capture apparatus  104 , optional compression hardware (not shown), provisional memory  108 , and other optional components such as control logic, sensor(s), etc. (not shown) to remain in the provisional capture state for extended periods of time. 
         [0032]    As may be appreciated, the memory  108  at any instant in time after initiation of the provisional capture state holds a record of previously received images. In the case of a digital video camera, such a historical record may include, for example, 1 to 60 seconds of previously captured images. As indicated above, such previously recorded images are written-over or overflowed and discarded while the system stays in the provisional capture state of operation. 
         [0033]    In the event a user decides that the images are to be saved, the overflow terminal  110  may be operatively coupled to a storage element  114  by a coupling device  112 . The coupling device  112  may, for example, be actuated by a user command such as a shutter button or trigger press. When the coupling device  112  couples the output terminal  110  to a storage element  114 , the provisional images are transmitted out of provisional memory  108  and into storage  114 . In the example of  FIG. 1 , this event may be envisioned as closing a user-activated switch  112  to couple the output line  110  of memory  108  to storage element  114 . Alternative interfaces between memory  108  and storage  114  such as bus-mediated serial or parallel data transfer, transistors, relays, or other controllable connections, etc., may be used. Images coupled to storage  114  are thus captured “permanently” as with a conventional digital camera or digital video recorder. 
         [0034]    The period during which images are cached in memory  108 , inter alia, allows a user time to respond to and record a dynamic event that would otherwise have been missed. To a user, pressing the shutter button or trigger performs what seems like capturing an image of the past (or at least capturing data beginning from a moment earlier than the real time moment the user activated the coupling device  112 ). 
         [0035]    Thus, according to embodiments, baby&#39;s first steps, an athletic achievement, a spectacular “wipe-out,” a noteworthy quote, or other transient event may be captured without requiring storage and later editing of large amounts of data. According to embodiments, a portable image or voice capture system may remain in provisional capture mode for an extended period of time without allocating large amounts of non-volatile memory to data that would need to be later deleted. Non-volatile memory or storage is only allocated to image (audio, etc.) storage when the provisionally captured real time event possesses qualities that the user judges to merit allocation of non-volatile memory or storage. 
         [0036]    As indicated above, the capture apparatus  104  and provisional memory  108  may, according to some embodiments, be integrated and made very low power. Actions that require more power, such as transmitting and/or permanently storing the image signal, may thus be eliminated during provisional image capture, reducing overall power consumption and enhancing battery life compared to conventional recorders that only permanently record images. 
         [0037]    According to embodiments, the capture apparatus  102  and other variants may include a digital hand-held still camera, a digital hand-held video camera, a camera phone, a computer with web-cam, a digital voice recorder, a head-mounted camera, a wireless headset, or other apparatus with a recording capability. 
         [0038]      FIG. 2  illustrates a retrospective recorder  201  having an electronic controller  202 , such as a microcontroller, interconnected with the capture apparatus  104 , provisional memory  108 , human interface  206 , and storage apparatus  114  via a bus  204 . According to an embodiment, the human interface  206  may include a record switch, shutter button, trigger, etc. configured to select the operating mode. When the user selects a provisional capture mode, the captured signal from the capture apparatus  104  may be loaded into the provisional memory  108 , which then overflows or is overwritten while the retrospective recorder  201  remains in provisional capture mode. When the user recognizes that the real time actions (which have been provisionally captured) warrant permanent recording, the user may activate the human interface  206  to change to a recording mode of operation. When the record mode is entered, provisional data from the provisional memory  108  may be transferred to storage memory  114  as the capture apparatus  104  continues to capture the action. 
         [0039]    For example, in the record mode, the microcontroller  202  may transfer provisional images from the provisional memory  108  to the storage  114  across the bus  204 . Alternatively, for embodiments where provisional image memory and the image storage are implemented as one or an array of physical devices, microcontroller  202  may, when a “record” command is received, allocate memory holding provisional images as storage to prevent the images from being written-over. 
         [0040]      FIG. 3  illustrates a retrospective recorder embodiment  301  including a local capture apparatus  104 , local memory  302 , a local controller  202 , a human interface  206 , and a data interface  304  coupled together by a data bus  204 . A portion of the local memory  302  may be configured as provisional memory. According to one embodiment, another or a selectable portion of the local memory  302  may be configured as permanent storage. According to another embodiment, the apparatus  301  may be substantially devoid of permanent image memory and instead, when a user command to enter record mode is received through the human interface  206 , provisionally captured images are transferred out through the data interface  304  as an output signal  308 . The data interface is here exemplified by a wireless interface, such as a transmitter/receiver, having an antenna  306  that is configured to transmit the image data as modulated radio signal  308 . Images selected for retrospective capture may thus be permanently retained on remote storage (not shown). 
         [0041]    According to one illustrative embodiment, the retrospective recorder  102  is embedded in a wireless communication device such as a cellular telephone, and the modulated radio signal  308  represents transmission to a conventional cellular telephone system. According to another exemplary embodiment, retrospective recorder  102  is configured as a head-mounted and/or bore-sighted video camera, and modulated radio signal  308  represents a short range signal such as a Bluetooth link, IEEE 802.11 link or other wireless link to a nearby receiving and storage apparatus. According to other embodiments, a wired interface, an infrared interface, or other non-radio interface may be substituted for the radio interface illustrated in  FIG. 3 . 
         [0042]      FIG. 4  illustrates a receiving device or network for receiving image data from a remote retrospective recording device  102  such as shown in the illustrative embodiment  301  of  FIG. 3 . A gateway  404 , which may be a base station, a cellular receiver, an embedded interface in a portable storage device, or other embodiment, receives a wireless signal  308  containing image data through an antenna  402 . The gateway  404  may transmit the received image data across an optional network  406 . The image signal may be received by a client computer  408 , by a server  410 , or other entity. As mentioned above, in some embodiments the system  401  may be replaced by a local receiving and storing device such as a personal computer, personal data assistant, MP3 player, or other apparatus equipped to receive and record image signals. 
         [0043]      FIG. 5  illustrates an alternative embodiment of a retrorespective recorder  501  that does not use physically- or logically-separated provisional memory  108 . Instead, a stream of images is captured by an image capture apparatus  104  and, under control of microcontroller  202 , is recorded into storage  114 . A user may, upon witnessing a noteworthy event, activate trigger  502 . The trigger signal is received by microcontroller  202 , and microcontroller  202  activates encoder  504 . According to an illustrative embodiment, an encoder  504  creates a mark indicating a moment in time and encodes the mark over the image stream in storage  114 , such as by steganography. Alternatively, a mark may be encoded in an index or other facility out-of-band with respect to the recorded image signals in storage  114 . Such out-of-band marks may be physically stored in storage  114  or may be stored in a separate physical apparatus. Thus, the marks provide sorting of images and may facilitate later editing and/or selection of images by directing the editor&#39;s or viewer&#39;s attention to those portions of images that were deemed noteworthy at the time of recording. 
         [0044]    According to an embodiment, the mark references a moment in the image stream earlier than the real time moment the user activates the trigger  502 . 
         [0045]    According to embodiments, the image stream may consist of or include audio information. 
         [0046]      FIG. 6  is a flowchart illustrating exemplary logic  601  for moving between provisional recording and permanent recording. As shown, the recorder enters an idle state  602  when powered. In the idle state  602 , the system may light meter the scene, automatically focus, zoom, set audio sensitivity, etc. Proceeding to decision step  604 , system checks to determine if it has been triggered to enter a provisional capture state  606 . If not instructed to enter a provisional capture state  606 , the system proceeds to decision step  603  where the logic checks to determine if a stop or shutdown command has been received. If a stop command has been received, the process ends, for example by performing a shutdown or entering a sleep mode. If the stop command has not been received, the system re-enters the idle state  602 . 
         [0047]    If provisional capture is selected in decision step  604 , the retrospective recorder enters provisional capture mode  606 . In provisional capture mode, images, audio, etc. are provisionally captured by a capture apparatus and are temporarily cached in a provisional memory circuit as provisional data. For the case of substantially continuous images such as video or audio, images may be temporarily cached as streaming data types. For the case of discontinuous images such as where the image capture device is a digital still camera (in still camera mode), discrete images are capture by the image capture device at a frame rate that may be selected by the designer or user according to preferences, and provisionally saved as one or more of a series of discrete images. 
         [0048]    While in the provisional capture mode  606 , the system monitors inputs in decision step  608  to determine if the user wishes to abort provisional capture mode  606 . If an abort command is received, the process proceeds to decision step  603 , from there either back to the idle state  606  or to the shutdown or sleep state as described above. If no abort command is received, the process proceeds from step  608  to step  610 , where it is determined if a command has been received to enter the record state  612 . If not, the system returns to the provisional capture state  606 . 
         [0049]    If user input is received (indicating that the user wishes to permanently record the provisionally captured image or images), the process proceeds to step  612 . In step  612 , the system may copy images from the image cache into storage starting with the earliest provisional image. Alternatively, the shutter button or trigger input may act as a command to capture the current image at a high resolution and to transfer lower resolution provisional images to storage. Thus, a high resolution digital image may be accompanied by an earlier (and later) series of images showing events leading up to the image, set-up, posing, etc. 
         [0050]    When the system or user issues a command to permanently store provisionally captured images as detected in decision step  610 , the system enters a storage mode  612  where one or more previously captured images are written to permanent storage or otherwise designated as permanent images. Such action may be embodied by physically copying the image signal to a separate storage device or physically segregated a region of memory. Alternatively, such action may be embodied by designating regions of memory for storage of the provisionally captured images currently held. 
         [0051]    When in storage mode  612 , the system monitors for a command to end storage in decision step  614  and return to provisional capture mode  606 . According to some embodiments, such a command may be interpreted as arising from release of a shutter button or trigger. Alternatively, the command to exit the storage mode may be made by a second depression of the shutter button or trigger. Alternatively, such a command may be interpreted as arising from storing all images that were substantially in the cache at the moment in time the record command  610  was received. Alternatively, the images from the capture apparatus may continue to be communicated to the storage apparatus for a timed period. Other alternatives will be apparent to those skilled in the art. 
         [0052]      FIG. 7  is a perspective view of a head-mounted and/or bore-sighted retrospective recording camera  702  mounted on eyewear  704  that may be worn by a user. The illustrative eyewear  704  may be substituted for by a helmet, headset, harness, etc. that may be worn by a user. Camera  702  includes a lens  706  for receiving and focusing light from a scene witnessed by the human wearer and a human interface  206  embodied as a button on the body of the retrospective recording camera  702  for selecting operating modes. For example, a single click indicates the user wishes to enter provisional capture. A second single click indicates the user wishes to record. In some embodiments, an extended click causes images to be permanently recorded for as long as button  206  is depressed. In other embodiments, a second click initiates permanent recording, and images are streamed out of local memory until an “exit record mode” command is issued, such as by another click when in record mode to indicate that the user wishes to exit record mode and resume provisional capture mode. A double click may indicate that the user wishes to abort provisional capture and enter idle mode or power down the head-mounted camera  702 . As illustrated in  FIG. 7 , the head-mounted camera  702  may include a wireless interface for transmitting images to a remote storage apparatus. Alternatively, some or all of the storage memory may be disposed within the camera  702 . 
         [0053]    A system may include a remote storage apparatus (not shown) having integrated wireless interface, logic for receiving images across the wireless interface, and storage. The remote storage apparatus may be carried in a pocket, held by a belt clip, or otherwise retained on the body of a user. The user may, for instance, simultaneously wear the head-mounted camera apparatus  702 . 
         [0054]    While various aspects and embodiments have been disclosed herein, other aspects and embodiments are contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.