Any Way to Autojoin Images From Multiple 4MP or 8MP Digital Cameras?

Discussion in 'Digital Photography' started by Will, May 26, 2005.

  1. Will

    Will Guest

    I have a fixed position application that requires top down macro pictures of
    printed circuit boards. From a previous thread, it appears that even a 12
    MP camera may not be enough to cover the area I need covered with sufficient
    detail. We aren't budgeted for a good 12 MP camera unfortunately.

    Does any vendor make a 4 MP or 8 MP camera that can be mounted in either a
    pair or quad configuration, together with software that will coordinate
    taking pictures will all cameras simultaneously then autojoining them into
    one larger image? The application would probably require a stand that
    allowed for the mounting of multiple cameras pointing down.
     
    Will, May 26, 2005
    #1
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  2. Will

    Colin D Guest

    If I remember correctly, you earlier specified a maximum board size of a
    foot square. You shouldn't need a 12 MPixel camera for that, but it
    depends on what you want to resolve. I guess the worst case would be a
    populated board with surface-mount components as small as
    rice-grain-sized resistors (I forget their wattage at that size).

    For interest I shot an old computer mainboard measuring about 9 inches x
    12 inches with a Canon 300D 6.3 Mpixel camera and a 17-85mm zoom lens.

    That lens is by no means optimal for this application, but nevertheless
    it resolved the values printed on the SM resistors, like 221, 103, etc,
    and of course IC markings, as well as tracks and silk-screened board
    markings.

    I would think that a Canon 350D or 20D, with an 8 megapixel sensor and a
    genuine macro lens - not a zoom macro - would be considerably better
    than my camera, and would do the job.

    Depending where you are located, you may be able to rent a 350D and
    macro lens for trial.

    A proper macro lens is desirable, as it will be rectilinear, that is,
    straight lines will be rendered straight, without the curvilinear
    distortion exhibited by zoom lenses, as well as being corrected for
    close distances.

    Colin
     
    Colin D, May 26, 2005
    #2
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  3. Will

    Frank ess Guest

    It's been mentioned that the macro-designated lenses are expected to
    perform well "flat field", and a circuit board is probably pretty
    close to that.

    If it turns out to be true that you need more than one 8MP image to
    cover the board successfully, and do need to join multiple images, I
    wonder why you need them made simultaneously. It should be relatively
    easy for an engineer to come up with a template to guide placement of
    the board for consecutive images that would include the whole board in
    four shots. Elapsed time between shots couldn't be more than a few
    seconds, and location very consistent, in those circumstances. With
    practice, and perhaps computer control, four exposures ought to be
    accomplished in five seconds, don't you think?
     
    Frank ess, May 26, 2005
    #3
  4. Will

    chrlz Guest

    You got me interested, so I grabbed my 8Mp prosumer (Oly C8080), and
    ran off a very crudely lit (on-camera flash- yeeuch!) image of an old
    decrepit 386 mobo I had lying nearby. The mobo is about 12" x 10".
    Here is an actual-pixel-sized crop of the outermost lower-right corner
    of that image - the crop represents about 2.5 x 2.2" of reality.. I
    thought I would show you that area as it should represent the worst
    lens performance, and please pardon the noise, I souped it up and
    over-sharpened!

    http://image44.webshots.com/44/5/15/83/353651583UVTwob_ph.jpg

    Here is the full (but NOT full-res, see below) image for comparison:

    http://image38.webshots.com/38/5/46/54/353654654KoPhDj_fs.jpg

    BUT, bear in mind I had to resize the second shot down from 3264 pixels
    wide to 2400 to comply with webshots requirements. It still gives a
    fair idea of resolution, but use the crop to get a better idea..

    I find it pretty easy to read all the stuff on there and with better
    lighting and more care in shooting (and also taking into account these
    shots were contrasted up and jpegged) you should be able to achieve
    better performance, but probably not much. The Oly C8080 has one of
    the best, if not *the* best, zoom lenses in this category of camera, by
    the way.. For what it's worth, it was shot at about 50mm zoom
    equivalence, hand held from a couple of feet away. Hope this helps to
    give you a baseline.
    Again there is the stitching issue, but you might want to investigate
    the costs of A3 scanners.. might work out cheaper than two digicams,
    would certainly solve the resolution problem... Make sure it isn't an
    'LIDE' type scanner, as these have almost zero depth of field.
     
    chrlz, May 26, 2005
    #4
  5. Depending on your needs, a program like AutoStitch (designed for making
    panoramas) may do:

    http://www.cs.ubc.ca/~mbrown/autostitch/autostitch.html

    David
     
    David J Taylor, May 26, 2005
    #5
  6. Will

    chrlz Guest

    I grabbed my 8Mp prosumer (Oly C8080), and
    Sorry, links to full images don't appear to work. If you are still
    interested, go here and then you have to click on the "View Full Size"
    link to see the full images..

    Crop:
    http://community.webshots.com/photo/262782767/353651583UVTwob

    Full-frame:
    http://community.webshots.com/photo/262782767/353654654KoPhDj

    (for anyone who is not following the thread, these are boring, noisy,
    poorly lit images of an old circuitboard - please do not judge my
    abilities on them.. (O:)
     
    chrlz, May 26, 2005
    #6
  7. Will

    Paul Furman Guest


    Also the macro lens will be equally sharp in the corners and center.


    This makes sense and easier to group the images for panorama stitching.
     
    Paul Furman, May 26, 2005
    #7
  8. Will

    Paul Mitchum Guest

    Not exactly what you're looking for, but along the same lines,
    especially in terms of automated stitching:

    <http://www.ecs.soton.ac.uk/~km/projs/vasari/>

    Maybe it'll give you a few ideas. :)
     
    Paul Mitchum, May 26, 2005
    #8
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