Depth triggered auto record

Abstract

The invention relates to an underwater digital video camera having an auto record system for automatically starting and stopping video recording at predetermined depths. The camera receives a current depth from a depth gauge and holds a sequence of recent currents depths and auto record settings such as a start trigger depth and a stop trigger depth, wherein the auto record system is adapted to, after the start/stop trigger depth is arrived at or passed for increasing/decreasing depths, start/stop video recording.

Claims

1. An underwater digital video camera having an auto record system for automatically starting and stopping video recording, a depth gauge to provide a current depth of the video camera to the auto-record system, and digital storage accessible by the auto record system for holding auto record settings and a sequence of recent currents depths from the depth gauge, wherein the auto record settings in the digital storage comprise: a start trigger depth; and a stop trigger depth; wherein the auto record system is configured to: after the start trigger depth is arrived at or passed while the current depth is increasing, start video recording; and after the stop trigger depth is arrived at or passed while the current depth is decreasing, stop video recording.

2. The underwater digital video camera according to claim 1, wherein the auto record settings in the digital storage further comprise a stop delay, and wherein the auto record system is adapted to stop of video recording a time equal to the stop delay after the stop trigger depth is arrived at or passed for decreasing depths.

3. The underwater digital video camera according to claim 1, wherein the auto record settings in the digital storage further comprise a start delay, and wherein the auto record system is adapted to start of video recording a time equal to the start delay after the start/stop trigger depth is arrived at or passed for increasing depths.

4. The underwater digital video camera according to claim 1, wherein one or more of the auto record settings can be adjusted by a user.

5. The underwater digital video camera according to claim 1, wherein the digital storage holds one or more auto-record profiles being sets of auto record settings, which can be selected by a user.

6. A method, performed by an auto record system of an underwater digital video camera, for automatically starting and stopping video recording, the underwater digital video camera comprising a digital storage holding a sequence of recent current depths and auto record settings comprising a start trigger depth and a stop trigger depth, the method comprising the following to be performed repeatedly: if the video camera is not recording and if the current depth is increasing, determine whether the start trigger depth has been arrived at or passed; if the start trigger depth has not been arrived at or passed, then determine the current depth and add it to the sequence of recent currents depths; if the start trigger depth has been arrived at or passed, then start recording; if the video camera is not recording and if the current depth is decreasing, determine the current depth and add it to the sequence of recent currents depths; if the video camera is recording and if the current depth is decreasing, determine whether the stop trigger depth has been arrived at or passed; if the stop trigger depth has not been arrived at or passed, then determine the current depth and add it to the sequence of recent currents depths; if the stop trigger depth has been arrived at or passed, then stop recording; and if the video camera is recording and if the current depth is increasing, determine the current depth and add it to the sequence of recent current depths.

7. The method according to claim 6, wherein the auto record settings comprise a stop delay and wherein recording is stopped a time equal to the stop delay after the stop trigger depth is arrived at or passed for decreasing depths.

8. The method according to claim 6, wherein the auto record settings comprise a start delay and wherein recording is started a time equal to the start delay after the start trigger depth is arrived at or passed for increasing depths.

9. The method according to claim 6, further comprising determining whether the current depth is increasing or decreasing based at least in part on the sequence of recent current depths.

10. The method according to claim 6, wherein the underwater digital video camera is coupled to a human diver.

11. The underwater digital video camera according to claim 2, wherein the stop delay is adjustable by a user of the underwater digital video camera.

12. The underwater digital video camera according to claim 2, wherein the stop delay is a predetermined stop delay greater than or equal to an expected time for a diver to surface from the stop trigger depth.

13. The underwater digital video camera according to claim 1, wherein the auto record system determines whether the current depth is increasing or decreasing based at least in part on the sequence of recent current depths.

14. The underwater digital video camera according to claim 1, wherein the auto record settings in the digital storage further comprise: a start delay, wherein the auto record system is adapted to start video recording a time equal to the start delay after the start trigger depth is arrived at or passed for increasing depths; and a stop delay, wherein the auto record system is adapted to stop video recording a time equal to the stop delay after the stop trigger depth is arrived at or passed for decreasing depths.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates a time-depth development of a dive with indication of auto-record settings.

(2) FIG. 2 illustrates a video camera according to an embodiment of the invention.

(3) FIG. 3 is a flow chart illustrating an architecture of software for an implementation of the invention.

DETAILED DESCRIPTION

(4) FIG. 1 illustrates a time-depth development of a dive, with the auto record settings start trigger depth 1, stop trigger depth 2 and stop delay 3 shown (start delay=0 is not shown). At 4, the diver enters the water and is shortly under water before returning to the surface as mentioned above. At 5, the diver arrives at or passes the start trigger depth 1 and the auto-record system initiates video recording. At 6, the diver arrives at or passes the stop trigger depth 2 and the auto-record system triggers the countdown of the stop delay 3. At 7 the diver breaks the surface to finish the dive, and the auto-record system awaits expiry of the stop delay 3 before stopping video recording at 8.

(5) The stop delay is relevant for example in recreational diving when the user desires to also catch the moment when of breaking the surface and the excitement during the first exchanges of the highlights between dive buddies. For underwater hunting it is often desirable to have the chance to inspect a potential catch after arriving at the surface.

(6) In all sorts of diving, with the exception of military diving, it is good practice to return to the surface after entering the water, to check and brief with dive buddies and assistance on land/boat. Therefore, even though a diver wants the camera to start recording at shallow depths, it may not be desirable that the camera starts recording immediately since the first arrival at this shallow depth is when jumping in the water. So, in order not to create a 1-2 seconds video clip of the last part of the jump (arrived at start trigger depth) and the return to surface (arrived at stop trigger depth), the recording start can also be delayed a fixed amount of time, the start delay.

(7) FIG. 2 illustrates a video camera 11 having imaging optics 12, a digital image sensor 13, a processor 14, memory 15, a depth gauge 16 to provide a current depth of the video camera to the control system and a battery 17. The auto-record system is provided by the processor in the form of an ASIC or software to be executed by the processor. The auto-record system will typically be part of a larger system for operating the video camera. The auto-record settings are parameters such as the start/stop trigger depth and the start/stop delay used by the auto-record system and which are stored in the memory 15.

(8) In one embodiment, the auto-record system has preset auto-record profiles, i.e. a set of auto-record settings, adapted for individual users or types of diving. It is preferred that the auto-record system involves a user interface where the user can adjust the individual auto-record settings or chose an auto-record profile.

(9) FIG. 3 is a flowchart illustrating the architecture of the software or ASIC of the auto-record system in accordance with an embodiment of the invention. It is noted that there are many different possible architectures that can all implement the invention, and that the embodiment of FIG. 3 is just one example.

(10) In the embodiment of FIG. 3, the auto-record system receives a depth or depth-related pressure data from an electric depth gauge 18 and determines (30) a current depth D.sub.n of the video camera as well as the last determined depth D.sub.n1. If the camera is not recording, the auto-record system proceeds to figure out if it should start recording. First, it determines whether the depth is currently increasing, and if, whether the start trigger depth D.sub.start has been arrived at or passed with the arrival at D.sub.n, and if, start recording after a time equal to the start delay, delay.sub.start. If delay.sub.start=0 it will start recording immediately.

(11) If the depth is not increasing, auto-record system returns to step 30.

(12) If the start trigger depth D.sub.start has not been arrived at or passed with the arrival at D.sub.n, then the user is either at a shallower depth or has passed D.sub.start previously and has manually turned off recording in the meantime. The auto-record system returns to step 30 and will monitor whether the diver arrives at or passes D.sub.start (again) for increasing depths.

(13) If the camera is recording, the auto-record system proceeds to figure out if it should stop recording. The process is equivalent to the process for recording start described above.

(14) The auto-record settings D.sub.start, D.sub.stop, delay.sub.start and delay.sub.stop are all stored in the memory 15 and retrieved by the auto-record system when needed.

(15) The depth gauge 16 to provide a current depth of the video camera 1 to the auto-record system may be an electric depth gauge 18 comprised by the video camera or a communication link to an external electric depth gauge 18 positioned close to the video camera and being in communication with the camera, such as via a wired or wireless communication link. Such external depth gauge would measure the depth of the depth gauge and not of the video camera and should therefore be close to the video camera, typically carried by the user of the video camera, so that it would measure the depth of the video camera +/max. 0.5 meter. In the present description, the depth measured by such close, external depth gauge is also referred to as the depth of the video camera.

(16) A depth gauge is most commonly a pressure sensor measuring a pressure of the water surrounding the sensor. Other types of depth gauges exist and may be used in the invention. For a pressure sensor, the pressure P as a function of depth in the is given by:
P=P.sub.0+gd.sub.G
where P.sub.0 is the air pressure at the upper surface of the water, is the water density (1000 kg/m3), g is the acceleration due to gravity (9.8 m/s2) and d.sub.G is the depth of the depth gauge. Preferably, the pressure sensor is calibrated to return the gauge pressure P.sub.G=PP.sub.0, which is the pressure difference relative to the air pressure. The gauge pressure can be used to determine the depth of the depth gauge:
d.sub.G=P.sub.G/g.

(17) The depth gauge will typically transmit depth data at short intervals so that a sequence of depths D.sub.n1, D.sub.n, D.sub.n+1 is steadily received by the auto-record system.

(18) The auto-record system can involve an override functionality. If for example the user manually activates a start/stop recording button on the camera before, during, or after the recording period decided by the auto-record settings, this may override or even cancel the auto-record. Alternatively, it will only lead to the user prematurely starting or stopping recording for that specific dive.

(19) The invention is in particular relevant for activities involving a large number of short consecutive dives, such as snorkeling and in particular spear fishing. There is often a lot of waiting time between dives that is of little interest and starting and stopping recording at each dive is cumbersome.

(20) Other areas are dive situations with a high requirement of documentation, where video recording is default and where the diver's attention to other tasks is essential. This refers to underwater archeology, military operations or search & rescue operations in particular, as well as educational and industrial diving in general.