A little more on Pi and coding.
Never coded one before (never seen one before!) and not sure if this is python or something else, but the scripts look super easy.
We'll have to play with x,y and res on each scanner (I know at least the HPs are supported, could not remember the model for the Canon to check. I'd want standard to be 600 dpi). Also, it seems it can only save TIFF, so we'll have to play with whether it's better to have the Pi convert to jpg (which may take time underwater), or leave as TIFF and see if there is space (perhaps get an even bigger card, but probably not needed - I don't imagine getting more than 15 images on one outing, or any images taking more than 500mb of space), then copy when I come up. We will need access to get the SD card and batteries out for recharge, whether it through opening the whole case or if these are just on the side….
Finally, here's the main command we are using in our code:
If that code I sent yesterday works (again, seems simple), we can use different buttons on the scanner for 300 dpi or 600 dpi, for example, or perhaps play with the lighting if its accessible depending on the button. Or, we can just have all buttons do the same thing, since I normally go with a specific size and don't want to accidentally hit the wrong one under water.
If we call this from command line, we can probably see what all the variables do (if not, we can still test from command line):
Here's some lamp control for the HP scanners we use, but it's only on or off, and threshold for black/brightness, not making it brighter:
Chat to Bryan
He believes likely building a better track and chain will do a lot to support the motor, since it is only supported in one direction, and this may prevent or at least prolong burn out. They also do use crappy motors nowadays (early 2000s Epsons used better ones apparently - he often takes apart scanners for parts, though has never rebuilt one). If we wanted to try and replace, it might mess up the software, but less of a risk if we use the same kind of motor: DC vs stepper, torque, power. These are different depending on the scanner. May be worth trying as well.
I imagine the same holds true of the lamp in terms of power consumption. Thoughts are that we could replace with a more efficient/bright lamp with the same consumption, or, since we are opening the case anyhow, add an additional lamp that is powered directly from one of the batteries, but not through the scanner.…. I _will_ have some wiggle room in photoshop, as long as _some_ information is there under the light.
Distance and depth of field
Thinking about Cherise's questions, the depth of field/focus has been designed as ideal where the glass ends. The two questions we probably want answered for each scanner are how far back is still in focus, and how far back is seen at varying degrees of light. A follow-up would be, what happens if we add more light? And another, if there are simple ways to make this distance greater. When I think about it, if necessary I might be ok with a small lens, as long as its macro, but then we'd need to definitely turn off the lamp, and add external lights.
Scanner cameras:
How scanner works:
But here, we can access the actual lenses inside, perhaps replace them (tricky, both in practice and in which lenses to use, but worth considering):
Good stuff!
Have a good weekend,
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