1. This forum section is a read-only archive which contains old newsgroup posts. If you wish to post a query, please do so in one of our main forum sections (here). This way you will get a faster, better response from the members on Motherboard Point.

Tablet/phone cameras

Discussion in 'Embedded' started by Don Y, Jun 16, 2011.

  1. Don Y

    Don Y Guest

    Hi,

    I currently have a kiosk application that I would like
    to port to a wireless, *portable* implementation. So,
    small tablets or (ack!) smart-phones (with the phone
    functionality permanently and irreparably disabled)
    seem a good choice. Phones being better suited in
    terms of size (want to tuck this into a shirt-pocket
    while not in use).

    But, I rely extensively on barcodes to provide data to
    the application (item identification, location identification,
    etc.).

    Since (some) cell phones currently have QR code capabilities,
    I figure adding that to a camera-equipped tablet (or phone)
    is a potential solution.

    Before I get myself "pregnant" on a solution path, I need
    to get a handle on what's "realistic" in terms of expectations.

    [I don't *use* cell phones so my ignorance here requires
    patience :> ]

    I know (some) cameras have motion video capabilities. From
    that, I can (?) deduce that the optics and electronics in
    the camera are "fast enough" that images can be captured
    at "several" frames per second.

    - does this effectively render the "phone" useless for
    other tasks (i.e., how CPU intensive is this task, how
    clumsy is the interface to the camera output, etc.)?

    - is this occurring at the same resolution as still pictures?
    or, is the camera degraded to a lower "movie mode"?

    The phones that I have played with require the camera to
    be explicitly "activated" (no doubt because the typical user
    doesn't want the camera on all the time -- privacy? performance?
    battery life??).

    - does the use of the camera (in movie mode) eat batteries?

    - is there some *other* significant start-up/run cost that
    is associated with the camera functionality?

    - does the *camera* drive the interface or does the application?
    By that, I mean, do you say, "go into movie mode" and then sit
    back and wait for the camera to deliver frames at whatever rate
    *it* wants? Or, do you say, "give me a frame, *now* (note that
    in this latter case, you could effectively run the video at
    2 FPS, 3 FPS, 12 FPS, etc. -- as appropriate to your application)

    What I would *like* to do is leave the camera on continuously and
    have my barcode recognizer/decoder processing images as fast as
    feasible. So, instead of the user having to explicitly enable
    the camera, point it at the targeted barcode label and *then*
    take a "capture barcode" snapshot, the application can hunt
    for suitable labels itself and use them as appropriate.

    Since the recognizer can be a resource pig, you would want to
    be able to control the rate at which it processes images. I.e.,
    "take a picture, process it, twiddle thumbs so other parts
    of the application can run, lather, rinse, repeat".

    Are there any other issues that could eat my lunch that I
    haven't considered?

    Finally, any pointers for *hackable* camera tablets/phones?
    (of course, they need to have some form of WiFi capability)

    Thx,
    --don
     
    Don Y, Jun 16, 2011
    #1
    1. Advertising

  2. Op Thu, 16 Jun 2011 16:54:47 +0200 schreef Don Y <>:
    > Hi,
    >
    > I currently have a kiosk application that I would like
    > to port to a wireless, *portable* implementation. So,
    > small tablets or (ack!) smart-phones (with the phone
    > functionality permanently and irreparably disabled)
    > seem a good choice. Phones being better suited in
    > terms of size (want to tuck this into a shirt-pocket
    > while not in use).
    >
    > But, I rely extensively on barcodes to provide data to
    > the application (item identification, location identification,
    > etc.).
    >
    > Since (some) cell phones currently have QR code capabilities,
    > I figure adding that to a camera-equipped tablet (or phone)
    > is a potential solution.


    Do be wary of the fact that there are two different kind of lenses used in
    camera phones:
    * "narrow focus": a focus light is used to determine the appropriate
    position of the lens
    * "wide/fixed focus": no moving parts or focus light needed

    Wide focus is used in cheap forward-facing lenses (for capturing your
    surroundings), fixed focus is used in cheap backward-facing lenses (for
    capturing yourself).

    > Before I get myself "pregnant" on a solution path, I need
    > to get a handle on what's "realistic" in terms of expectations.
    >
    > [I don't *use* cell phones so my ignorance here requires
    > patience :> ]
    >
    > I know (some) cameras have motion video capabilities. From
    > that, I can (?) deduce that the optics and electronics in
    > the camera are "fast enough" that images can be captured
    > at "several" frames per second.


    All phone camera's I've seen are fast enough to show captured images on
    the main LCD at several frames per second. Compressing and storing the
    data somewhere is a different matter.

    > - does this effectively render the "phone" useless for
    > other tasks (i.e., how CPU intensive is this task, how
    > clumsy is the interface to the camera output, etc.)?


    Without knowing the answer for any specific phone, I will go out on a limb
    and say: it depends.

    > - is this occurring at the same resolution as still pictures?
    > or, is the camera degraded to a lower "movie mode"?


    For my phone, movie mode is lower quality for a few reasons:
    1. data has to be compressed on-the-fly (with a video codec!)
    2. compressed data has to be stored on a slow SD card
    3. in lower quality, it doesn't matter whether the focus is exactly right
    4. audio is also captured, compressed and stored

    > The phones that I have played with require the camera to
    > be explicitly "activated" (no doubt because the typical user
    > doesn't want the camera on all the time -- privacy? performance?
    > battery life??).
    >
    > - does the use of the camera (in movie mode) eat batteries?


    Taking a picture is more than just grabbing a frame of data from the CCD,
    but also:
    * adjusting light sensitivity of the CCD (which might take many frames)
    * focussing the lens (which might take many frames)
    And in the 'default' setting also:
    * deciding whether to use the flash

    > - is there some *other* significant start-up/run cost that
    > is associated with the camera functionality?


    * loading the software that controls the camera (including any "cool
    effects" that might be provided in real-time, like sepia, negative,
    solarise, etc.)
    * charging the flash capacitor

    > - does the *camera* drive the interface or does the application?
    > By that, I mean, do you say, "go into movie mode" and then sit
    > back and wait for the camera to deliver frames at whatever rate
    > *it* wants? Or, do you say, "give me a frame, *now* (note that
    > in this latter case, you could effectively run the video at
    > 2 FPS, 3 FPS, 12 FPS, etc. -- as appropriate to your application)


    Since at the very least, light sensitivity adjustment will need to be made
    at a certain rate, frames will probably be grabbed at a fixed rate when
    the camera is active. I guess it is the choice of the application to skip
    as many frames as it needs to.

    > What I would *like* to do is leave the camera on continuously and
    > have my barcode recognizer/decoder processing images as fast as
    > feasible. So, instead of the user having to explicitly enable
    > the camera, point it at the targeted barcode label and *then*
    > take a "capture barcode" snapshot, the application can hunt
    > for suitable labels itself and use them as appropriate.


    Can you say "battery life" ? What if I'm sleeping? What if the phone is
    in my pocket?
    Also, you may not even have complete control over that; my camera phone
    has a sliding lens cap that triggers camera mode.

    > Since the recognizer can be a resource pig, you would want to
    > be able to control the rate at which it processes images. I.e.,
    > "take a picture, process it, twiddle thumbs so other parts
    > of the application can run, lather, rinse, repeat".


    It would be a great advantage if the phone had an accelerometer. Then you
    can grab more frames if the phone is held still while viewing a suitably
    bright object.

    > Are there any other issues that could eat my lunch that I
    > haven't considered?
    >
    > Finally, any pointers for *hackable* camera tablets/phones?
    > (of course, they need to have some form of WiFi capability)
    >
    > Thx,
    > --don



    --
    Gemaakt met Opera's revolutionaire e-mailprogramma:
    http://www.opera.com/mail/
    (Remove the obvious prefix to reply privately.)
     
    Boudewijn Dijkstra, Jun 16, 2011
    #2
    1. Advertising

  3. Don Y

    linnix Guest

    On Jun 16, 10:11 am, "Boudewijn Dijkstra"
    <> wrote:
    > Op Thu, 16 Jun 2011 16:54:47 +0200 schreef Don Y <>:


    My comments are mostly for Android camera phones (i.e. LG VS740).

    > > Hi,

    >
    > > I currently have a kiosk application that I would like
    > > to port to a wireless, *portable* implementation.  So,
    > > small tablets or (ack!) smart-phones (with the phone
    > > functionality permanently and irreparably disabled)
    > > seem a good choice.  Phones being better suited in
    > > terms of size (want to tuck this into a shirt-pocket
    > > while not in use).

    >
    > > But, I rely extensively on barcodes to provide data to
    > > the application (item identification, location identification,
    > > etc.).


    Phones cameras are more geared for 2D barcodes, but i guess old
    fashion barcodes are workable.

    >
    > > Since (some) cell phones currently have QR code capabilities,
    > > I figure adding that to a camera-equipped tablet (or phone)
    > > is a potential solution.

    >
    > Do be wary of the fact that there are two different kind of lenses used in  
    > camera phones:
    > * "narrow focus": a focus light is used to determine the appropriate  
    > position of the lens
    > * "wide/fixed focus": no moving parts or focus light needed
    >
    > Wide focus is used in cheap forward-facing lenses (for capturing your  
    > surroundings), fixed focus is used in cheap backward-facing lenses (for  
    > capturing yourself).


    My phone has only auto focused forward-facing lens.

    >
    > > Before I get myself "pregnant" on a solution path, I need
    > > to get a handle on what's "realistic" in terms of expectations.

    >
    > > [I don't *use* cell phones so my ignorance here requires
    > > patience  :> ]

    >
    > > I know (some) cameras have motion video capabilities.  From
    > > that, I can (?) deduce that the optics and electronics in
    > > the camera are "fast enough" that images can be captured
    > > at "several" frames per second.

    >


    Motion video are captured and processed in SDRAM (256M in my case)
    first. Single hi-res (upto 2000x1500) takes couple of seconds. The
    jpeg file can be several megabytes compressed.

    > All phone camera's I've seen are fast enough to show captured images on  
    > the main LCD at several frames per second.  Compressing and storing the 
    > data somewhere is a different matter.
    >
    > > - does this effectively render the "phone" useless for
    > > other tasks (i.e., how CPU intensive is this task, how
    > > clumsy is the interface to the camera output, etc.)?


    You can always write your custom camera app: Java for Android.

    >
    > Without knowing the answer for any specific phone, I will go out on a limb  
    > and say: it depends.
    >
    > > - is this occurring at the same resolution as still pictures?
    > > or, is the camera degraded to a lower "movie mode"?

    >
    > For my phone, movie mode is lower quality for a few reasons:
    > 1. data has to be compressed on-the-fly (with a video codec!)
    > 2. compressed data has to be stored on a slow SD card
    > 3. in lower quality, it doesn't matter whether the focus is exactly right
    > 4. audio is also captured, compressed and stored
    >
    > > The phones that I have played with require the camera to
    > > be explicitly "activated" (no doubt because the typical user
    > > doesn't want the camera on all the time -- privacy? performance?
    > > battery life??).

    >
    > > - does the use of the camera (in movie mode) eat batteries?


    Yes, you have to keep charging it.

    >
    > Taking a picture is more than just grabbing a frame of data from the CCD, 
    > but also:
    > * adjusting light sensitivity of the CCD (which might take many frames)
    > * focussing the lens (which might take many frames)
    > And in the 'default' setting also:
    > * deciding whether to use the flash
    >
    > > - is there some *other* significant start-up/run cost that
    > > is associated with the camera functionality

    >
    > * loading the software that controls the camera (including any "cool  
    > effects" that might be provided in real-time, like sepia, negative,  
    > solarise, etc.)
    > * charging the flash capacitor
    >
    > > - does the *camera* drive the interface or does the application?
    > > By that, I mean, do you say, "go into movie mode" and then sit
    > > back and wait for the camera to deliver frames at whatever rate
    > > *it* wants?  Or, do you say, "give me a frame, *now* (note that
    > > in this latter case, you could effectively run the video at
    > > 2 FPS, 3 FPS, 12 FPS, etc. -- as appropriate to your application)

    >


    Build-in app only do single shot or video (fixed 15 FPS, i believed).
    Of course, you can write your custom apps.

    > Since at the very least, light sensitivity adjustment will need to be made  
    > at a certain rate, frames will probably be grabbed at a fixed rate when  
    > the camera is active.  I guess it is the choice of the application to skip  
    > as many frames as it needs to.
    >
    > > What I would *like* to do is leave the camera on continuously and
    > > have my barcode recognizer/decoder processing images as fast as
    > > feasible.  So, instead of the user having to explicitly enable
    > > the camera, point it at the targeted barcode label and *then*
    > > take a "capture barcode" snapshot, the application can hunt
    > > for suitable labels itself and use them as appropriate.

    >


    You will have to write your custom apps.

    > Can you say "battery life" ?  What if I'm sleeping?  What if the phone is  
    > in my pocket?
    > Also, you may not even have complete control over that; my camera phone  
    > has a sliding lens cap that triggers camera mode.
    >
    > > Since the recognizer can be a resource pig, you would want to
    > > be able to control the rate at which it processes images.  I.e.,
    > > "take a picture, process it, twiddle thumbs so other parts
    > > of the application can run, lather, rinse, repeat".

    >
    > It would be a great advantage if the phone had an accelerometer.  Then you  
    > can grab more frames if the phone is held still while viewing a suitably  
    > bright object.
    >
    > > Are there any other issues that could eat my lunch that I
    > > haven't considered?

    >
    > > Finally, any pointers for *hackable* camera tablets/phones?
    > > (of course, they need to have some form of WiFi capability)


    I would go for a rooted Android. Unfortunately, theVS740 is hard to
    root.

    >
    > > Thx,
    > > --don

    >
    > --
    > Gemaakt met Opera's revolutionaire e-mailprogramma:  http://www.opera.com/mail/
    > (Remove the obvious prefix to reply privately.)
     
    linnix, Jun 16, 2011
    #3
  4. Don Y

    Don Y Guest

    Hi Boudewijn,

    On 6/16/2011 10:11 AM, Boudewijn Dijkstra wrote:
    >> Since (some) cell phones currently have QR code capabilities,
    >> I figure adding that to a camera-equipped tablet (or phone)
    >> is a potential solution.

    >
    > Do be wary of the fact that there are two different kind of lenses used
    > in camera phones:
    > * "narrow focus": a focus light is used to determine the appropriate
    > position of the lens
    > * "wide/fixed focus": no moving parts or focus light needed
    >
    > Wide focus is used in cheap forward-facing lenses (for capturing your
    > surroundings), fixed focus is used in cheap backward-facing lenses (for
    > capturing yourself).


    Gack! You've confused me.

    OK, my understanding was that the *original* cameras in
    phones (so far, we haven't talked about tablets) were on
    the "back" of the phone. I.e., while viewing the screen
    (the "main" screen -- since some phones have more than one),
    you would be looking in the same direction that the camera
    was "pointed". (so, the camera would be imaging what you see
    *beyond* the phone as you look at the screen)

    I guess this is what you call the "forward-facing" lens?

    Some phones appear to have a little adjustment "lever" on
    this lens (rotate it 90 degrees about the center of the
    lens to cause ____________).

    You mentioned narrow and wide/fixed. Then, went on to
    describe wide and fixed. Are wide/fixed synonyms? In
    which case, what about "narrow" (is this what would be
    called "macro" on a digital camera?)

    >> I know (some) cameras have motion video capabilities. From
    >> that, I can (?) deduce that the optics and electronics in
    >> the camera are "fast enough" that images can be captured
    >> at "several" frames per second.

    >
    > All phone camera's I've seen are fast enough to show captured images on
    > the main LCD at several frames per second. Compressing and storing the
    > data somewhere is a different matter.


    But, the display in most (?) phones seems to be lower quality
    than the stated camera capabilities. Is this real-time display
    deliberately discarding data? I.e., it exists solely to help
    the user get an idea of what the camera is shooting? Like
    a "preview" mode in a page scanner?

    Does the application have to do anything to make this data
    available to the display (i.e., is the application copying
    data from camera to display or is there a special data path
    that is enabled to make this happen "for free")

    >> - does this effectively render the "phone" useless for
    >> other tasks (i.e., how CPU intensive is this task, how
    >> clumsy is the interface to the camera output, etc.)?

    >
    > Without knowing the answer for any specific phone, I will go out on a
    > limb and say: it depends.


    <grin>
    <frown>

    >> - is this occurring at the same resolution as still pictures?
    >> or, is the camera degraded to a lower "movie mode"?

    >
    > For my phone, movie mode is lower quality for a few reasons:
    > 1. data has to be compressed on-the-fly (with a video codec!)
    > 2. compressed data has to be stored on a slow SD card
    > 3. in lower quality, it doesn't matter whether the focus is exactly right
    > 4. audio is also captured, compressed and stored


    OK. None of those allow you to conclude that the phone is
    incapable of *processing* data at that rate (i.e., and
    discarding it)

    >> The phones that I have played with require the camera to
    >> be explicitly "activated" (no doubt because the typical user
    >> doesn't want the camera on all the time -- privacy? performance?
    >> battery life??).
    >>
    >> - does the use of the camera (in movie mode) eat batteries?

    >
    > Taking a picture is more than just grabbing a frame of data from the
    > CCD, but also:
    > * adjusting light sensitivity of the CCD (which might take many frames)
    > * focussing the lens (which might take many frames)
    > And in the 'default' setting also:
    > * deciding whether to use the flash


    It would be very "unfriendly" if the device had to keep taking flash
    photos. So, I will assume there will be enough ambient light to
    capture the images required.

    Adjusting light sensitivity can be ongoing -- because the camera
    is "on always". I guess this is the dimming/brightening effect
    you tend to see when the camera is first "enabled".

    Is the camera focused mechanically? What role does the application
    software take in doing that? Does the application *know* when the
    scene is "in focus" or do you rely on the user delaying "snapping"
    the picture until the displayed image "looks good"?

    >> - is there some *other* significant start-up/run cost that
    >> is associated with the camera functionality?

    >
    > * loading the software that controls the camera (including any "cool
    > effects" that might be provided in real-time, like sepia, negative,
    > solarise, etc.)


    So, the camera isn't just "turned on and off" but, rather, treated
    as an application in its own right.

    > * charging the flash capacitor
    >
    >> - does the *camera* drive the interface or does the application?
    >> By that, I mean, do you say, "go into movie mode" and then sit
    >> back and wait for the camera to deliver frames at whatever rate
    >> *it* wants? Or, do you say, "give me a frame, *now* (note that
    >> in this latter case, you could effectively run the video at
    >> 2 FPS, 3 FPS, 12 FPS, etc. -- as appropriate to your application)

    >
    > Since at the very least, light sensitivity adjustment will need to be
    > made at a certain rate, frames will probably be grabbed at a fixed rate


    This suggests that the *camera* does this adjustment? Or, is it in
    the "camera application"? I.e., do I have any control over it?

    > when the camera is active. I guess it is the choice of the application
    > to skip as many frames as it needs to.
    >
    >> What I would *like* to do is leave the camera on continuously and
    >> have my barcode recognizer/decoder processing images as fast as
    >> feasible. So, instead of the user having to explicitly enable
    >> the camera, point it at the targeted barcode label and *then*
    >> take a "capture barcode" snapshot, the application can hunt
    >> for suitable labels itself and use them as appropriate.

    >
    > Can you say "battery life" ? What if I'm sleeping? What if the phone is
    > in my pocket?


    This will be used in an industrial setting. I.e., turned off
    at the end of a shift. Possibly returned to a "charging base"
    frequently during the day (if folks learn that it is prudent
    to do so).

    If its in your pocket, then it won't see anything (and will just
    waste battery life).

    Note that the application will obviously idle the "phone" (which
    could be a tablet, recall) when it notices that it isn't being
    actively used.

    > Also, you may not even have complete control over that; my camera phone
    > has a sliding lens cap that triggers camera mode.
    >
    >> Since the recognizer can be a resource pig, you would want to
    >> be able to control the rate at which it processes images. I.e.,
    >> "take a picture, process it, twiddle thumbs so other parts
    >> of the application can run, lather, rinse, repeat".

    >
    > It would be a great advantage if the phone had an accelerometer. Then
    > you can grab more frames if the phone is held still while viewing a
    > suitably bright object.


    Ah! That's an excellent idea! If the camera is "in motion",
    then, chances are, the *image* won't be "in focus". And,
    regardless, the user will not be "focussed" on a particular
    barcoded object.

    So, you could almost idle the camera -- just doing brightness
    compensation and, possibly, some crude scene processing to
    augment the accelerometer's idea of whether or not the
    device is "moving".

    Thanks! There's a fair bit to chew on...
     
    Don Y, Jun 16, 2011
    #4
  5. Op Thu, 16 Jun 2011 20:25:34 +0200 schreef Don Y <>:
    > On 6/16/2011 10:11 AM, Boudewijn Dijkstra wrote:
    >>> Since (some) cell phones currently have QR code capabilities,
    >>> I figure adding that to a camera-equipped tablet (or phone)
    >>> is a potential solution.

    >>
    >> Do be wary of the fact that there are two different kind of lenses used
    >> in camera phones:
    >> * "narrow focus": a focus light is used to determine the appropriate
    >> position of the lens
    >> * "wide/fixed focus": no moving parts or focus light needed
    >>
    >> Wide focus is used in cheap forward-facing lenses (for capturing your
    >> surroundings), fixed focus is used in cheap backward-facing lenses (for
    >> capturing yourself).

    >
    > Gack! You've confused me.


    You expectorate a hairball when confused?

    > OK, my understanding was that the *original* cameras in
    > phones (so far, we haven't talked about tablets) were on
    > the "back" of the phone. I.e., while viewing the screen
    > (the "main" screen -- since some phones have more than one),
    > you would be looking in the same direction that the camera
    > was "pointed". (so, the camera would be imaging what you see
    > *beyond* the phone as you look at the screen)
    >
    > I guess this is what you call the "forward-facing" lens?


    Yes.

    > Some phones appear to have a little adjustment "lever" on
    > this lens (rotate it 90 degrees about the center of the
    > lens to cause ____________).


    Hmm, I didn't even think about hand-operated lenses.

    > You mentioned narrow and wide/fixed. Then, went on to
    > describe wide and fixed. Are wide/fixed synonyms? In
    > which case, what about "narrow" (is this what would be
    > called "macro" on a digital camera?)


    No, wide and fixed are not synonyms. Wide focus means the image is sharp
    over a wide range (like in a disposable camera), fixed focus means the
    image is only sharp at a fixed distance. Analogously, narrow focus means
    the image is sharp only in a narrow (but not fixed) distance range. IIRC
    "macro" is for short distances only, and involves dynamic mechanical zoom
    (which most phone cameras don't provide).

    But, I was just trying to illustrate that some lenses need time (and
    energy) to focus on the object of interest.

    >>> I know (some) cameras have motion video capabilities. From
    >>> that, I can (?) deduce that the optics and electronics in
    >>> the camera are "fast enough" that images can be captured
    >>> at "several" frames per second.

    >>
    >> All phone camera's I've seen are fast enough to show captured images on
    >> the main LCD at several frames per second. Compressing and storing the
    >> data somewhere is a different matter.

    >
    > But, the display in most (?) phones seems to be lower quality
    > than the stated camera capabilities. Is this real-time display
    > deliberately discarding data?


    It has no choice but to create a scaled version of the image. What's
    wrong with that?

    > I.e., it exists solely to help
    > the user get an idea of what the camera is shooting? Like
    > a "preview" mode in a page scanner?


    Yes.

    > Does the application have to do anything to make this data
    > available to the display (i.e., is the application copying
    > data from camera to display or is there a special data path
    > that is enabled to make this happen "for free")


    Dunno.

    >> Taking a picture is more than just grabbing a frame of data from the
    >> CCD, but also:
    >> * adjusting light sensitivity of the CCD (which might take many frames)
    >> * focussing the lens (which might take many frames)
    >> And in the 'default' setting also:
    >> * deciding whether to use the flash

    >
    > It would be very "unfriendly" if the device had to keep taking flash
    > photos. So, I will assume there will be enough ambient light to
    > capture the images required.
    >
    > Adjusting light sensitivity can be ongoing -- because the camera
    > is "on always". I guess this is the dimming/brightening effect
    > you tend to see when the camera is first "enabled".


    Yes.

    > Is the camera focused mechanically?


    Depends on the lens type, as mentioned above.

    > What role does the application
    > software take in doing that? Does the application *know* when the
    > scene is "in focus" or do you rely on the user delaying "snapping"
    > the picture until the displayed image "looks good"?


    My phone camera has a "dual action" button like in regular cameras. Press
    it softly and it will try to focus (which may fail), press it all the way
    to capture the image. If you press it all the way directly, it will first
    try to focus. The user is notified when the camera thinks that the image
    is focused. But, it will only know after trying to focus. So it is an
    interactive process.

    >>> - is there some *other* significant start-up/run cost that
    >>> is associated with the camera functionality?

    >>
    >> * loading the software that controls the camera (including any "cool
    >> effects" that might be provided in real-time, like sepia, negative,
    >> solarise, etc.)

    >
    > So, the camera isn't just "turned on and off" but, rather, treated
    > as an application in its own right.


    Yes. In order to conserve resources, I presume.

    >>> - does the *camera* drive the interface or does the application?
    >>> By that, I mean, do you say, "go into movie mode" and then sit
    >>> back and wait for the camera to deliver frames at whatever rate
    >>> *it* wants? Or, do you say, "give me a frame, *now* (note that
    >>> in this latter case, you could effectively run the video at
    >>> 2 FPS, 3 FPS, 12 FPS, etc. -- as appropriate to your application)

    >>
    >> Since at the very least, light sensitivity adjustment will need to be
    >> made at a certain rate, frames will probably be grabbed at a fixed rate

    >
    > This suggests that the *camera* does this adjustment? Or, is it in
    > the "camera application"? I.e., do I have any control over it?


    Dunno. But why would you want to mess with it?



    --
    Gemaakt met Opera's revolutionaire e-mailprogramma:
    http://www.opera.com/mail/
    (Remove the obvious prefix to reply.)
     
    Boudewijn Dijkstra, Jun 17, 2011
    #5
  6. Don Y

    larwe Guest

    On Jun 16, 10:54 am, Don Y <> wrote:

    > I know (some) cameras have motion video capabilities.  From
    > that, I can (?) deduce that the optics and electronics in
    > the camera are "fast enough" that images can be captured
    > at "several" frames per second.


    This is highly variable. To run off a few possibilities - some phones/
    tablets have the camera on an internal USB interface. Some have the
    image sensor connected directly to a dedicated port on the SoC (this
    would almost always be the case for cameras). To acquire images, you
    have to power up the sensor, enable a DMA channel (for the dedicated
    camera port type solution), maybe instruct the GPU to set up an
    overlay window to perform YUV->RGB conversion. Exposure and white
    balance are typically adjusted on the fly by host-side software but
    this is certainly not universally true, especially for the USB
    solutions. The frame rate will typically be some divisor of 60Hz, for
    some resolution which might be anything from 160x120 up to full HD
    resolution depending on the camera. Some cameras, especially higher
    resolution cameras, have mechanical autofocus.

    Notice how I'm using words like "variable" "typical" etc. These
    systems can range from a single-core 400MHz ARM9 to a dual-core 1.2GHz
    Cortex with a separate DSP and/or other coprocessor(s), so there is
    absolutely no one size fits all answer.

    These sensors also typically require fairly long exposure times, so
    simply waving the camera about won't acquire a good image - you need
    to select a subject and hold the sensor still while acquiring the
    image. Usually, the live-view mode is significantly lower resolution
    than the sensor's actual max resolution.

    > - does the use of the camera (in movie mode) eat batteries?


    Sure, because you have powered up the sensor, moved the CPU core into
    a higher power mode, possibly activated a separate DSP core to handle
    MPEG compression, possibly powered up additional segments of the GPU
    (if any) to handle the overlay window, increased RAM bandwidth usage,
    forced the screen to remain on with 100% duty cycle, ... ... ...

    > - does the *camera* drive the interface or does the application?


    And for this you should start by looking at the APIs offered by the OS
    in the device you intend to use, because life's too short for hacking
    below the OS level in this case - especially if you want to insulate
    yourself against supply chain changes.
     
    larwe, Jun 17, 2011
    #6
  7. Don Y

    Don Y Guest

    On 6/16/2011 11:11 AM, linnix wrote:
    > On Jun 16, 10:11 am, "Boudewijn Dijkstra"
    > <> wrote:
    >> Op Thu, 16 Jun 2011 16:54:47 +0200 schreef Don Y<>:

    >
    > My comments are mostly for Android camera phones (i.e. LG VS740).
    >
    >>> Hi,

    >>
    >>> I currently have a kiosk application that I would like
    >>> to port to a wireless, *portable* implementation. So,
    >>> small tablets or (ack!) smart-phones (with the phone
    >>> functionality permanently and irreparably disabled)
    >>> seem a good choice. Phones being better suited in
    >>> terms of size (want to tuck this into a shirt-pocket
    >>> while not in use).

    >>
    >>> But, I rely extensively on barcodes to provide data to
    >>> the application (item identification, location identification,
    >>> etc.).

    >
    > Phones cameras are more geared for 2D barcodes, but i guess old
    > fashion barcodes are workable.


    Yes -- hence my mention of QR (below). It's conceivable that
    you could decode linear ("classic") barcodes but they would
    probably need to be printed at exaggerated scales to get the
    proper discrimination between wide/narrow bars/spaces.

    >>> Before I get myself "pregnant" on a solution path, I need
    >>> to get a handle on what's "realistic" in terms of expectations.

    >>
    >>> [I don't *use* cell phones so my ignorance here requires
    >>> patience :> ]

    >>
    >>> I know (some) cameras have motion video capabilities. From
    >>> that, I can (?) deduce that the optics and electronics in
    >>> the camera are "fast enough" that images can be captured
    >>> at "several" frames per second.

    >
    > Motion video are captured and processed in SDRAM (256M in my case)


    So, if there is enough horsepower (or, clever enough recognizer),
    the image could be examined -- and discarded -- relatively quickly
    (i.e., no need to compress and/or store it)

    > first. Single hi-res (upto 2000x1500) takes couple of seconds. The
    > jpeg file can be several megabytes compressed.


    >>> - does the use of the camera (in movie mode) eat batteries?

    >
    > Yes, you have to keep charging it.


    Every 3 minutes? 2 hours? etc.? You have to "keep charging" a
    cell phone *regardless*... the point is how much of an impact
    it makes on battery life, relatively speaking. (e.g., does
    phone w/ radio off, camera on consume as much/more/less than
    phone w/ radio on, camera off, etc.?

    >> Since at the very least, light sensitivity adjustment will need to be made
    >> at a certain rate, frames will probably be grabbed at a fixed rate when
    >> the camera is active. I guess it is the choice of the application to skip
    >> as many frames as it needs to.
    >>
    >>> What I would *like* to do is leave the camera on continuously and
    >>> have my barcode recognizer/decoder processing images as fast as
    >>> feasible. So, instead of the user having to explicitly enable
    >>> the camera, point it at the targeted barcode label and *then*
    >>> take a "capture barcode" snapshot, the application can hunt
    >>> for suitable labels itself and use them as appropriate.

    >
    > You will have to write your custom apps.


    Yes, I plan on writing most everything "from scratch" as I suspect
    it will be *more* work to try to coerce a device made for one
    type of use into a very different type of usage (see comments
    re: software reuse thread :> )

    >>> Are there any other issues that could eat my lunch that I
    >>> haven't considered?

    >>
    >>> Finally, any pointers for *hackable* camera tablets/phones?
    >>> (of course, they need to have some form of WiFi capability)

    >
    > I would go for a rooted Android. Unfortunately, theVS740 is hard to
    > root.


    Thanks, I'll look and see what's around with my basic needs
    (incl tablets).
     
    Don Y, Jun 17, 2011
    #7
  8. Don Y

    Don Y Guest

    Hi Boudewijn,

    On 6/17/2011 1:26 AM, Boudewijn Dijkstra wrote:

    [attributions elided]

    >> You mentioned narrow and wide/fixed. Then, went on to
    >> describe wide and fixed. Are wide/fixed synonyms? In
    >> which case, what about "narrow" (is this what would be
    >> called "macro" on a digital camera?)

    >
    > No, wide and fixed are not synonyms. Wide focus means the image is sharp
    > over a wide range (like in a disposable camera), fixed focus means the
    > image is only sharp at a fixed distance. Analogously, narrow focus means
    > the image is sharp only in a narrow (but not fixed) distance range. IIRC
    > "macro" is for short distances only, and involves dynamic mechanical
    > zoom (which most phone cameras don't provide).


    Ah, OK. "depth of field".

    > But, I was just trying to illustrate that some lenses need time (and
    > energy) to focus on the object of interest.
    >
    >>>> I know (some) cameras have motion video capabilities. From
    >>>> that, I can (?) deduce that the optics and electronics in
    >>>> the camera are "fast enough" that images can be captured
    >>>> at "several" frames per second.
    >>>
    >>> All phone camera's I've seen are fast enough to show captured images on
    >>> the main LCD at several frames per second. Compressing and storing the
    >>> data somewhere is a different matter.

    >>
    >> But, the display in most (?) phones seems to be lower quality
    >> than the stated camera capabilities. Is this real-time display
    >> deliberately discarding data?

    >
    > It has no choice but to create a scaled version of the image. What's
    > wrong with that?


    I'm not claiming there is anything *wrong* with it! :> Rather,
    I am wondering how much of a "fortunate circumstance" this is for
    the phone implementor? I.e., knowing he only has to *display*
    ~1/4 of the data that he's taking in?

    >> What role does the application
    >> software take in doing that? Does the application *know* when the
    >> scene is "in focus" or do you rely on the user delaying "snapping"
    >> the picture until the displayed image "looks good"?

    >
    > My phone camera has a "dual action" button like in regular cameras.
    > Press it softly and it will try to focus (which may fail), press it all
    > the way to capture the image. If you press it all the way directly, it
    > will first try to focus. The user is notified when the camera thinks
    > that the image is focused. But, it will only know after trying to focus.
    > So it is an interactive process.


    But, there is nothing that prevents a piece of code from making
    that decision (albeit possibly "less well")?

    >>>> - does the *camera* drive the interface or does the application?
    >>>> By that, I mean, do you say, "go into movie mode" and then sit
    >>>> back and wait for the camera to deliver frames at whatever rate
    >>>> *it* wants? Or, do you say, "give me a frame, *now* (note that
    >>>> in this latter case, you could effectively run the video at
    >>>> 2 FPS, 3 FPS, 12 FPS, etc. -- as appropriate to your application)
    >>>
    >>> Since at the very least, light sensitivity adjustment will need to be
    >>> made at a certain rate, frames will probably be grabbed at a fixed rate

    >>
    >> This suggests that the *camera* does this adjustment? Or, is it in
    >> the "camera application"? I.e., do I have any control over it?

    >
    > Dunno. But why would you want to mess with it?


    Just rying to understand what's involved, what's "canned", what's
    likely to be "proprietary", what's clonable, etc.
     
    Don Y, Jun 17, 2011
    #8
  9. Don Y

    Don Y Guest

    Hi Lewin,

    On 6/17/2011 6:42 AM, larwe wrote:
    > On Jun 16, 10:54 am, Don Y<> wrote:
    >
    >> I know (some) cameras have motion video capabilities. From
    >> that, I can (?) deduce that the optics and electronics in
    >> the camera are "fast enough" that images can be captured
    >> at "several" frames per second.

    >
    > This is highly variable. To run off a few possibilities - some phones/
    > tablets have the camera on an internal USB interface. Some have the
    > image sensor connected directly to a dedicated port on the SoC (this
    > would almost always be the case for cameras). To acquire images, you
    > have to power up the sensor, enable a DMA channel (for the dedicated
    > camera port type solution), maybe instruct the GPU to set up an
    > overlay window to perform YUV->RGB conversion. Exposure and white
    > balance are typically adjusted on the fly by host-side software but
    > this is certainly not universally true, especially for the USB


    But these aren't (as) important when processing monochromatic
    video (e.g., barcode symbols).

    > solutions. The frame rate will typically be some divisor of 60Hz, for
    > some resolution which might be anything from 160x120 up to full HD
    > resolution depending on the camera. Some cameras, especially higher
    > resolution cameras, have mechanical autofocus.
    >
    > Notice how I'm using words like "variable" "typical" etc. These
    > systems can range from a single-core 400MHz ARM9 to a dual-core 1.2GHz
    > Cortex with a separate DSP and/or other coprocessor(s), so there is
    > absolutely no one size fits all answer.


    Understood.

    > These sensors also typically require fairly long exposure times, so


    So, "motion video" is, of necessity, pretty poor quality?

    Is the issue related to luminance, too (instead of just chrominance)?

    > simply waving the camera about won't acquire a good image - you need
    > to select a subject and hold the sensor still while acquiring the
    > image. Usually, the live-view mode is significantly lower resolution
    > than the sensor's actual max resolution.
    >
    >> - does the use of the camera (in movie mode) eat batteries?

    >
    > Sure, because you have powered up the sensor, moved the CPU core into
    > a higher power mode, possibly activated a separate DSP core to handle
    > MPEG compression, possibly powered up additional segments of the GPU
    > (if any) to handle the overlay window, increased RAM bandwidth usage,
    > forced the screen to remain on with 100% duty cycle, ... ... ...


    As expected. But, many of these things I can live without or
    have to deal with already. E.g., I don't have to worry about
    compression because I'm not saving images. How the video is
    displayed is entirely up to me (if it is displayed at all!).
    CPU will already tend to be running at a higher duty cycle
    (imagine being *on* the phone all the time it is powered up).
    Etc.

    >> - does the *camera* drive the interface or does the application?

    >
    > And for this you should start by looking at the APIs offered by the OS
    > in the device you intend to use, because life's too short for hacking
    > below the OS level in this case - especially if you want to insulate
    > yourself against supply chain changes.


    Supply chain won't be a problem in the quantities we're looking
    at. In the short term (prototyping), I suspect trying to
    fit some "middleware" above the OS to make it behave the way
    the application would *want* it to behave would be more work
    than gutting the device completely -- especially as it will
    need to be done *eventually*. Annoying to have a successful
    prototype and then have to "start over" to come up with a
    *real* product -- about which the prototype will have taught you
    very little! :-/
     
    Don Y, Jun 17, 2011
    #9
  10. Don Y

    linnix Guest

    On Jun 17, 11:03 am, Don Y <> wrote:
    > On 6/16/2011 11:11 AM, linnix wrote:
    >
    >
    >
    >
    >
    >
    >
    >
    >
    > > On Jun 16, 10:11 am, "Boudewijn Dijkstra"
    > > <>  wrote:
    > >> Op Thu, 16 Jun 2011 16:54:47 +0200 schreef Don Y<>:

    >
    > > My comments are mostly for Android camera phones (i.e. LG VS740).

    >
    > >>> Hi,

    >
    > >>> I currently have a kiosk application that I would like
    > >>> to port to a wireless, *portable* implementation.  So,
    > >>> small tablets or (ack!) smart-phones (with the phone
    > >>> functionality permanently and irreparably disabled)
    > >>> seem a good choice.  Phones being better suited in
    > >>> terms of size (want to tuck this into a shirt-pocket
    > >>> while not in use).

    >
    > >>> But, I rely extensively on barcodes to provide data to
    > >>> the application (item identification, location identification,
    > >>> etc.).

    >
    > > Phones cameras are more geared for 2D barcodes, but i guess old
    > > fashion barcodes are workable.

    >
    > Yes -- hence my mention of QR (below).  It's conceivable that
    > you could decode linear ("classic") barcodes but they would
    > probably need to be printed at exaggerated scales to get the
    > proper discrimination between wide/narrow bars/spaces.
    >
    > >>> Before I get myself "pregnant" on a solution path, I need
    > >>> to get a handle on what's "realistic" in terms of expectations.

    >
    > >>> [I don't *use* cell phones so my ignorance here requires
    > >>> patience  :>  ]

    >
    > >>> I know (some) cameras have motion video capabilities.  From
    > >>> that, I can (?) deduce that the optics and electronics in
    > >>> the camera are "fast enough" that images can be captured
    > >>> at "several" frames per second.

    >
    > > Motion video are captured and processed in SDRAM (256M in my case)

    >
    > So, if there is enough horsepower (or, clever enough recognizer),
    > the image could be examined -- and discarded -- relatively quickly
    > (i.e., no need to compress and/or store it)
    >
    > > first.  Single hi-res (upto 2000x1500) takes couple of seconds.  The
    > > jpeg file can be several megabytes compressed.
    > >>> - does the use of the camera (in movie mode) eat batteries?

    >
    > > Yes, you have to keep charging it.

    >
    > Every 3 minutes?  2 hours? etc.?  You have to "keep charging" a
    > cell phone *regardless*...  the point is how much of an impact
    > it makes on battery life, relatively speaking.  (e.g., does
    > phone w/ radio off, camera on consume as much/more/less than
    > phone w/ radio on, camera off, etc.?
    >


    I took 10 pictures and the battery drop from 66% to 65%. So, i guess
    you can take 1000 pictures on a full charge.

    larwe: USB sensors are impractical beyond VGA. Need lots of memory
    and bandwidth on chip to do so. The 3M pixel sensor of VS740 has
    parallel data bus into the system DSP. Pictures are first captured in
    SDRAM, then write to SD card. However, in Linux, you can probably
    memory map the SDRAM for processing, but you need rooted Android. The
    camera software library is available in C++ (unsupported), but wrapper
    in Java (supported) available.
     
    linnix, Jun 17, 2011
    #10
  11. On 17.06.2011 20:08, Don Y wrote:

    > I'm not claiming there is anything *wrong* with it! :> Rather,
    > I am wondering how much of a "fortunate circumstance" this is for
    > the phone implementor? I.e., knowing he only has to *display*
    > ~1/4 of the data that he's taking in?


    None --- people do expect those images to look good shown on other
    displays, including ones considerably better than the phone's own one.
    And the image display has zooming capability, too, so you don't get away
    with all that much nonsense even before the image is uploaded somewhere.

    This mismatch between sensor resolution and on-camera display resolution
    has been with us since just about day 1 of digital photography. There
    is a reason most digicams still have viewfinders of some design.
     
    Hans-Bernhard Bröker, Jun 17, 2011
    #11
  12. Don Y

    Don Y Guest

    Hi Hans-Bernhard,

    On 6/17/2011 1:03 PM, Hans-Bernhard Bröker wrote:
    > On 17.06.2011 20:08, Don Y wrote:
    >
    >> I'm not claiming there is anything *wrong* with it! :> Rather,
    >> I am wondering how much of a "fortunate circumstance" this is for
    >> the phone implementor? I.e., knowing he only has to *display*
    >> ~1/4 of the data that he's taking in?

    >
    > None --- people do expect those images to look good shown on other
    > displays, including ones considerably better than the phone's own one.


    My point was concerned with the fact that the camera (software)
    need not have to deal with *processing* all that data for *display*
    in real-time. Presumably, this reduces the demands on that
    process ("fortunate circumstance" for the phone implementor)

    > And the image display has zooming capability, too, so you don't get away
    > with all that much nonsense even before the image is uploaded somewhere.
    >
    > This mismatch between sensor resolution and on-camera display resolution
    > has been with us since just about day 1 of digital photography. There is
    > a reason most digicams still have viewfinders of some design.
     
    Don Y, Jun 17, 2011
    #12
  13. Don Y

    larwe Guest

    On Jun 17, 2:17 pm, Don Y <> wrote:

    > > overlay window to perform YUV->RGB conversion. Exposure and white
    > > balance are typically adjusted on the fly by host-side software but
    > > this is certainly not universally true, especially for the USB

    >
    > But these aren't (as) important when processing monochromatic
    > video (e.g., barcode symbols).


    These sensors don't have a heck of a lot of dynamic range, so it's
    easy to wash out even a barcode. I think you really would be well
    served by buying a couple - for example go to www.dealextreme.com or
    www.merimobiles.com and look at some of their shanzai phones and
    tablets - and just experiment with them using the apps available in
    their app stores. None of them that I'm aware of support realtime
    decode - you acquire a picture, and then they analyze it.

    The augmented reality apps that work on a printed orientation glyph do
    almost exactly what you're talking about, but they don't need to read
    much information out of the shape, and they also incorporate other
    sensor input to make inferences about how the shape is moving around
    in the FOV.

    > > These sensors also typically require fairly long exposure times, so

    >
    > So, "motion video" is, of necessity, pretty poor quality?


    Varies :) For the low end, absolutely. At the extreme low end, even
    the resolution is very constrained.

    > have to deal with already.  E.g., I don't have to worry about
    > compression because I'm not saving images.  How the video is


    You don't care about it, but the APIs available to you may implicitly
    turn on those features. Getting fancy behind the scenes by poking at
    the power management features of the system will likely get the
    drivers/OS very confused.

    > need to be done *eventually*.  Annoying to have a successful
    > prototype and then have to "start over" to come up with a
    > *real* product -- about which the prototype will have taught you


    (choosing words with some care here) With a similar though not
    identical problem to solve, a large corporation with which I'm
    familiar has decided to approach this problem entirely at the app
    layer, and qualify individual devices.
     
    larwe, Jun 18, 2011
    #13
  14. Don Y

    Don Y Guest

    On 6/17/2011 11:23 AM, linnix wrote:
    >>>>> - does the use of the camera (in movie mode) eat batteries?

    >>
    >>> Yes, you have to keep charging it.

    >>
    >> Every 3 minutes? 2 hours? etc.? You have to "keep charging" a
    >> cell phone *regardless*... the point is how much of an impact
    >> it makes on battery life, relatively speaking. (e.g., does
    >> phone w/ radio off, camera on consume as much/more/less than
    >> phone w/ radio on, camera off, etc.?

    >
    > I took 10 pictures and the battery drop from 66% to 65%. So, i guess
    > you can take 1000 pictures on a full charge.


    <grin> I'm not sure if that extrapolation necesssarily
    follows from the empirical evidence. :> If that were
    the case, you could take 60 seconds of 15FPS video (?)

    > larwe: USB sensors are impractical beyond VGA. Need lots of memory
    > and bandwidth on chip to do so. The 3M pixel sensor of VS740 has
    > parallel data bus into the system DSP. Pictures are first captured in
    > SDRAM, then write to SD card. However, in Linux, you can probably
    > memory map the SDRAM for processing, but you need rooted Android. The
    > camera software library is available in C++ (unsupported), but wrapper
    > in Java (supported) available.


    Pointer to a URL?
     
    Don Y, Jun 18, 2011
    #14
  15. Don Y

    linnix Guest

    On Jun 18, 2:46 pm, Don Y <> wrote:
    > On 6/17/2011 11:23 AM, linnix wrote:
    >
    > >>>>> - does the use of the camera (in movie mode) eat batteries?

    >
    > >>> Yes, you have to keep charging it.

    >
    > >> Every 3 minutes?  2 hours? etc.?  You have to "keep charging" a
    > >> cell phone *regardless*...  the point is how much of an impact
    > >> it makes on battery life, relatively speaking.  (e.g., does
    > >> phone w/ radio off, camera on consume as much/more/less than
    > >> phone w/ radio on, camera off, etc.?

    >
    > > I took 10 pictures and the battery drop from 66% to 65%.  So, i guess
    > > you can take 1000 pictures on a full charge.

    >
    > <grin>  I'm not sure if that extrapolation necesssarily
    > follows from the empirical evidence.  :>  If that were
    > the case, you could take 60 seconds of 15FPS video (?)


    The pictures were taken over 20 to 30 seconds. So, you can probably
    run the phone for about an hour (pictures or video). The processors
    (600MHz CPU + 400MHz DSP) are the main battery killer anyway.

    >
    > > larwe: USB sensors are impractical beyond VGA.  Need lots of memory
    > > and bandwidth on chip to do so.  The 3M pixel sensor of VS740 has
    > > parallel data bus into the system DSP.  Pictures are first captured in
    > > SDRAM, then write to SD card.  However, in Linux, you can probably
    > > memory map the SDRAM for processing, but you need rooted Android.  The
    > > camera software library is available in C++ (unsupported), but wrapper
    > > in Java (supported) available.

    >
    > Pointer to a URL?


    google "android camera programming" will give you plenty to read.
     
    linnix, Jun 19, 2011
    #15
  16. Don Y

    Don Y Guest

    Hi Lewin,

    On 6/18/2011 4:03 AM, larwe wrote:
    > On Jun 17, 2:17 pm, Don Y<> wrote:
    >
    >>> overlay window to perform YUV->RGB conversion. Exposure and white
    >>> balance are typically adjusted on the fly by host-side software but
    >>> this is certainly not universally true, especially for the USB

    >>
    >> But these aren't (as) important when processing monochromatic
    >> video (e.g., barcode symbols).

    >
    > These sensors don't have a heck of a lot of dynamic range, so it's
    > easy to wash out even a barcode. I think you really would be well


    Dunno. I've never been particularly interested in the camera
    aspects of these devices before. I noticed that the cameras
    were "slow to start" and would typically take three "repaints"
    to get the brightness (?) sorted out in low light conditions
    (I would usually play with these in the evening hours so light
    wasn't overly abundant). I should take one outdoors and turn it
    on to see how that fares...

    > served by buying a couple - for example go to www.dealextreme.com or
    > www.merimobiles.com and look at some of their shanzai phones and
    > tablets - and just experiment with them using the apps available in
    > their app stores. None of them that I'm aware of support realtime
    > decode - you acquire a picture, and then they analyze it.


    I have several (older) smartphones that I've accumulated over
    the years. I used an HTC wizard for a few months while traveling
    as a "portable email (wifi) client". And, I know I have an
    assotment of Treos (kept because they have "keyboards" -- as does
    the wizard).

    But, since I don't *use* cell phones, I confess I've never played
    with anything other than the built-in applications...

    > The augmented reality apps that work on a printed orientation glyph do
    > almost exactly what you're talking about, but they don't need to read
    > much information out of the shape, and they also incorporate other
    > sensor input to make inferences about how the shape is moving around
    > in the FOV.


    I have the luxury of being able to bastardize the code for my own
    purposes -- though being able to read "real" QR codes might have
    some advantages (and DISadvantages).

    >>> These sensors also typically require fairly long exposure times, so

    >>
    >> So, "motion video" is, of necessity, pretty poor quality?

    >
    > Varies :) For the low end, absolutely. At the extreme low end, even
    > the resolution is very constrained.
    >
    >> have to deal with already. E.g., I don't have to worry about
    >> compression because I'm not saving images. How the video is

    >
    > You don't care about it, but the APIs available to you may implicitly
    > turn on those features. Getting fancy behind the scenes by poking at
    > the power management features of the system will likely get the
    > drivers/OS very confused.


    We'll either work on bare iron or contract the development of
    our own drivers to give us the features we want/need. We're not
    trying to be a "typical phone/tablet" so doubt solutions intended
    for those sorts of markets would fit well.

    >> need to be done *eventually*. Annoying to have a successful
    >> prototype and then have to "start over" to come up with a
    >> *real* product -- about which the prototype will have taught you

    >
    > (choosing words with some care here) With a similar though not
    > identical problem to solve, a large corporation with which I'm
    > familiar has decided to approach this problem entirely at the app
    > layer, and qualify individual devices.


    We want to be sure the devices are *not* usable for any purpose
    other than our own. And, we will have other I/O's that you
    just can't expect to get in a phone/tablet. So, rather than
    design yet another set of "peripherals" and figure out how to
    marry them to <whatever>, it makes more sense to roll all the
    development into one set of devices. This should also greatly
    simplify the maintenance of the system as well as the software.
     
    Don Y, Jun 20, 2011
    #16
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.

Share This Page