9 ms·

Poor man's document camera for videoconference

205 points by lrizzo 7y ago

shemnon42 7y ago
What's more valuable: The box of pasta or the roll of coins providing a counterweight?
- kernelsanderz 7y ago
  That's what I thought. Surely you could buy 10 professional document cameras for the value of that pasta! :-)
  - ddsea 7y ago
    At least this design doesn't need TP.
    - applecrazy 7y ago
      Never in my life would I have imagined that toilet paper is rarer and more valuable than boxed pasta.
- oaiey 7y ago
  I think he goes for the inexpensive solution. He could have used toilet paper as foundation :)
- mfontani 7y ago
  They're the smooth (lisce) penne, not the furrowed (rigate) variety. "nobody" uses those! At the start of the quarantine, when Italians went and stripped shops bare of goods despite all warnings about the supply chain being in no danger and there being no need to stock up on everything, this type of pasta was the only one left on most shelves. The reason for that _might_ have to do with the "fact" that it's more difficult to ensure pasta sauce sticks to the smooth type - the grooves help a LOT ensuring the sauce sticks well and homogeneously. As to why people would leave any type of food on shelves if they were truly thinking they'd need to stock up... I've no clue.
kernelsanderz 7y ago
Reminds me a kickstarter project I backed years ago called ScanBox. I still pull it out from time to time to scan documents when traveling, and have used it once or twice for a live document scanner, though the sides of the box make it difficult to get your hand into. These days our team either uses the built-in whiteboard functionality in Zoom, or jump into a Google Drawing or Slides document for the live collaboration. Sometimes I'll also use Zoom's AirPlay functionality to share my iPad screen and use an app like Notability to share. Though that's only one-way and not collabarative.
- seltzered_ 7y ago
  Had to look this up, neat: https://www.kickstarter.com/projects/limemouse/scanbox-turn-your-smartphone-into-a-portable-scann/description https://www.kickstarter.com/projects/limemouse/scanbox-turn-... Bonus points if someone can sell this feature within a notebook/tablet stand. Modifying a tiny tower stand (https://tinytowerstand.com/ https://tinytowerstand.com/) comes to mind.
  - tpetry 7y ago
    That‘s a really cool idea, does not need much space when not used :)
trevyn 7y ago
Just cut a slit the shape of the cardboard profile in the top of the pasta box and shove the cardboard in?
- zaroth 7y ago
  You would still need to fill the box with something heavier than pasta.
kohtatsu 7y ago
Re. orientation: the phone shouldn't be trying to determine landscape/portrait when flat; it should gracefully keep the previous state for at least a dozen degrees. On my 11 Pro it doesn't change until ~40 degrees of attitude.
- ckdarby 7y ago
  In Android there's an option to lock orientation.
  - yed 7y ago
    There's one in iOS as well.
    - lotsofpulp 7y ago
      Only for portrait mode. Never made sense to me why they only allow locking in one orientation and not landscape.
      - gtufano 7y ago
        It's "lock rotation", not "lock portrait". If you have the device in landscape when you lock it, it will lock in landscape.
        lotsofpulp 7y ago
        I just did it on an iphone 6S Plus and an iPhone XS both with ios13+, and while in landscape, if I press lock rotation, it changes to portrait and then locks it. I’ve experienced this since iPhone 3G or iPhone 4, so I assume this is how they have designed it. https://discussions.apple.com/thread/8237975 https://discussions.apple.com/thread/8237975 This website shows a workaround for it: https://www.igeeksblog.com/how-to-lock-rotation-in-iphone-landscape-mode/ https://www.igeeksblog.com/how-to-lock-rotation-in-iphone-la...
        manigandham 7y ago
montroser 7y ago
In these situations where you're taking a photograph of writing or a diagram on a piece of paper, it can be surprisingly tricky to get rid of the shading from the lighting conditions and be left with just the content on the page in high contrast. This explanation nails how to do it though: http://www.imagemagick.org/Usage/compose/#divide http://www.imagemagick.org/Usage/compose/#divide Divide a blurred copy by the original and you end up with effectively an adaptive-normalize filter where the result is nice and clear with the shadows and uneven lighting left behind. Also though, there are tools like https://miro.com https://miro.com and https://beta.plectica.com https://beta.plectica.com which kinda make this obsolete for many common use cases.
- tehlike 7y ago
  Google has photoscan app on Android that is pretty good.
- joshvm 7y ago
  Most commercial solutions solve this by using bright illumination from both sides to avoid shadows. In a pinch a couple of led under-cupboard light strips off would probably work. Something like: https://www.interactive-education.co.uk/product/visualisers/genee-vision-6100/ https://www.interactive-education.co.uk/product/visualisers/... It's almost always easier to control the illumination in the first place rather than fix it in post.
  - HarryHirsch 7y ago
    In the real world the "bright illumination from both sides" solution is called a makeup mirror. Just get one of those and glue the phone to it.
- dharma1 7y ago
  Notes has a good document scanner on iOS - https://support.apple.com/en-us/HT210336 https://support.apple.com/en-us/HT210336 Google Photoscan mentioned by someone else is also great, it's available on iOS and Android It takes a series of photos, and guides you to move the phone as the document is illuminated from different angles by the led flash. It then blends them for optimal result to eliminate glare
exikyut 7y ago
> frame rate, encoder quality. Especially low end phones do not have enough power to encode highly variable input (see previous bullet), resulting in unreadable images. An encoder setting for low frame rate (e.g. 1-2FPS) and high quality would be invaluable for such an use case. Ways to go even better: - Don't use an "<x>FPS" based model of continuous transmission - the paper isn't always updating by default - In extremely low-bandwidth situations, never update while there's a hand in the frame; only update once the paper image settles again - Get all fancy with feature detection and draw buttons on the corner of the paper; one of these could be "update" and the device would beep to acknowledge the frame had changed. This is actually practical as not everyone has bluetooth keyboards, audio-based commands would be distracting, and tapping onscreen buttons would nudge the device - Perform frame border analysis and automatically crop and rotate the actual paper as it's moved around
Cherian 7y ago
I don’t want to look like promotional, but recently a professor used an Osmo reflector (https://twitter.com/romps/status/1237617042338897921?s=12 https://twitter.com/romps/status/1237617042338897921?s=12) to project class notes and it caught on with teachers. A team worked through the weekend and released a free app to make this super easy (https://twitter.com/PlayOsmo/status/1241152565083090947 https://twitter.com/PlayOsmo/status/1241152565083090947). While the base + reflector is not free, if you already have an Osmo game at home, you can reuse that.
- jedberg 7y ago
  OMG, this is exactly what I needed! I've been working from home for five years, and the one big missing piece was "whiteboarding". I even have an extra Osmo reflector and base! Now I just have to convince the kids to stop playing Osmo long enough so that I can use it. :) Thank you!
robbrown451 7y ago
When I use my phone camera to copy documents or especially photographs (i.e. old school printed-on-paper paper photos), I've found the most useful thing is to light it with the sun. You can do it next to a window if the sun is shining in (best the window is clean), or I just do it on my porch if it isn't windy. They come out with excellent quality...I have found it does better than even scanning them (which takes much longer) Obviously, the sun should be at enough of an angle so it won't cause glare. You can try to position it so the sky isn't reflecting in the photo, but honestly the effect of that is going to be miniscule because the sun is so much brighter. And of course, if you have to do it when the sun isn't out, you can make do with whatever lighting you have, but the quality won't be as good from my experience. I've done this for family photos from ages ago, and it wasn't a problem to wait for some sunshine.
- martin-adams 7y ago
  If you have to use indoor lighting, find a flat object to lay it on, then tilt it parallel to the light so your hand is less likely to cast a shadow.
Hnrobert42 7y ago
Off topic, but as OP is from the .it TLD, it’s interesting to note OP prefers riga pasta, especially in light of this article: https://qz.com/1811768/coronavirus-lockdown-ignites-an-old-italian-debate-its-about-pasta-of-course/ https://qz.com/1811768/coronavirus-lockdown-ignites-an-old-i...
- number6 7y ago
  Related Note: Referring to this method as poor man's method while using a pack of pasta while pasta is as hard to get as TP. Pun intended?
- martopix 7y ago
  (unipi.it: University of Pisa)
  - martopix 7y ago
    Also, smooth pasta is embarassing.
    - stclaus 7y ago
      that's why they're using it for something else than meals :)
mhenr18 7y ago
I couldn't resist trying this and making some more detailed instructions for getting better images out of iOS. Turns out that you can get fairly good results without any fancy software. https://mhenr18.github.io/improvised-document-camera/ https://mhenr18.github.io/improvised-document-camera/
Aardwolf 7y ago
"Apollo 13 style camera stand" That name sounds amazing for being a box of pasta!
wallflower 7y ago
If you want to upgrade from DIY, Ipevo sells a line of document cameras that start at $99. Some are not as expensive as dedicated, stand alone classroom document cameras because they require a computer to operate. https://www.ipevo.com/products https://www.ipevo.com/products
deleted 7y ago
[deleted]
mkl 7y ago
A stack of books with a couple of rulers under the top one works better - it's height-adjustable. Moving a bit further up the quality ladder, I've just built myself a solid laptop/monitor stand out of plywood, and I'm going to attach a strut sticking out the back to hold up a webcam-as-document-camera and (when it arrives) an LED ring light. There are actually a whole lot of cheap products based around the phone-as-document-camera idea, e.g. https://www.aliexpress.com/item/4000309823825.html https://www.aliexpress.com/item/4000309823825.html, a stand, phone holder, and ring light.
klingonopera 7y ago
> "With so many people and students around the world working from home, we really need some easy to deploy shared whiteboard solution. This is especially important for pre-college students who may not have access to high end hardware." Just add a new mode to videoconferencing, where both parties get a white screen and both can start drawing and the resulting image stays in sync on both clients? (I feel like this solution is so obvious, I'm about to fly out a window - what am I missing?) Sounds like way less work for those already developing videoconferencing apps than to deploy stand-alone solutions in addition to that. In fact, phones could do good just having a "scratchpad" as a "phone-variant" of Notepad and/or Paint. It helps to quickly draw something, a simple sketch, or communication with deaf people or those who don't share a common language. It's sad to see the state of bloatware on phones and not seeing many useful things. It took ages for them to add the torch/flashlight feature as a standard into the OS, back in the day, we needed to use apps to get that done, so I think it's probably symptomatic of the entire industry. Hell, it's no wonder Apple can get away selling their expensive stuff, the others aren't really setting the bar high enough...
- lrizzo 7y ago
  >> "With so many people and students around the world working from home, we really need some easy to deploy shared whiteboard solution. This is especially important for pre-college students who may not have access to high end hardware." >Just add a new mode to videoconferencing, where both parties get a white screen and both can start drawing and the resulting image stays in sync on both clients? (I feel like this solution is so obvious, I'm about to fly out a window - what am I missing?) Author here. There have been a few proposals in this space for the past 25 years including hangouts extensions, using a virtual camera that just exports the screen (if people remember the old mbone tools wb and vic; I myself wrote an extension to replace the camera with a snapshot from a configurable region of the X screen), and my own shared whiteboard which gives parties a shared screen that they can edit modify replay ... http://info.iet.unipi.it/~luigi/wb/ http://info.iet.unipi.it/~luigi/wb/ There are two main reasons (in my opinion) why this space has been neglected: - almost nothing matches the convenience, speed and _resolution_ of writing and drawing with an actual pen. Pads with sufficient resolution and decent lag are only appearing now, and they are fragile and expensive. Graphic tablets are cheap but lack the visual feedback and looking at the output on the screen still has significant latency. They are moderately usable, but takes time to get used to them, and you need a real 10+in screen to use them effectively. Using a finger or a conductive pen on a phone screen is only good for small sketches, not for writing longer sentences or formulas. - the main users of such products would be non commercial entities (pre-college schools, students) so there are no paying customers. Even at college level lectures are increasingly based on slides prepared in advance. Businesses, of course, use slides or meet in person, and the whiteboard style of collaboration is generally done in person. Social distancing now may actually create more use cases and perhaps returns (in terms of actual money or social appreciation) that stimulate software solutions to appear. The Apollo13 problem still stands: even if we had good and cheap technology for writing, at this time it would be impossible to build and sell such products to customers, so we have to find solutions that use hardware already in possession of the users.
sandreas 7y ago
Thank you HN for this article and the comments. Years ago I wrote a little java command line tool based on BoofCV (Pure Java CV lib - https://boofcv.org/ https://boofcv.org/), tess4j (tesseract) and PDFBox to create PDFs with OCR and invisible Text Layer, to make its contents searchable like the OCR Option in PDF X Change Viewer. I used a combination of Thresholding and deskewing to improve my Documents (e.g. Sauvola, Nick) - see https://boofcv.org/index.php?title=Example_Thresholding https://boofcv.org/index.php?title=Example_Thresholding Now I plan to restore and improve the old code and provide it as open source solution :-) Hope the code still somewhere on my old harddisks.
bitfhacker 7y ago
I use a pile of book with the mobile phone on the top of them. For photos I use CamScanner free because it crops automatically the photo, auto contrast them and save multiple pages as a pdf.
zvonimirs 7y ago
Hi guys, founder of AWW (https://awwapp.com https://awwapp.com) here. AWW is one of the first and simplest online whiteboard on the market. Check us out. Also, for schools, we are giving free premium until the end of the COVID-19 situation. Stay safe everyone.
timtas 7y ago
Fine until you eat up all your other pasta. Then where are you? Well, I guess at that point you have bigger problems. :)

205 points by lrizzo 7y ago

shemnon42 7y ago

What's more valuable: The box of pasta or the roll of coins providing a counterweight?

kernelsanderz 7y ago
That's what I thought. Surely you could buy 10 professional document cameras for the value of that pasta! :-)
- ddsea 7y ago
  At least this design doesn't need TP.
  - applecrazy 7y ago
    Never in my life would I have imagined that toilet paper is rarer and more valuable than boxed pasta.
oaiey 7y ago
I think he goes for the inexpensive solution. He could have used toilet paper as foundation :)
mfontani 7y ago
They're the smooth (lisce) penne, not the furrowed (rigate) variety. "nobody" uses those! At the start of the quarantine, when Italians went and stripped shops bare of goods despite all warnings about the supply chain being in no danger and there being no need to stock up on everything, this type of pasta was the only one left on most shelves. The reason for that _might_ have to do with the "fact" that it's more difficult to ensure pasta sauce sticks to the smooth type - the grooves help a LOT ensuring the sauce sticks well and homogeneously. As to why people would leave any type of food on shelves if they were truly thinking they'd need to stock up... I've no clue.

kernelsanderz 7y ago

Reminds me a kickstarter project I backed years ago called ScanBox. I still pull it out from time to time to scan documents when traveling, and have used it once or twice for a live document scanner, though the sides of the box make it difficult to get your hand into. These days our team either uses the built-in whiteboard functionality in Zoom, or jump into a Google Drawing or Slides document for the live collaboration. Sometimes I'll also use Zoom's AirPlay functionality to share my iPad screen and use an app like Notability to share. Though that's only one-way and not collabarative.

seltzered_ 7y ago
Had to look this up, neat: https://www.kickstarter.com/projects/limemouse/scanbox-turn-your-smartphone-into-a-portable-scann/description https://www.kickstarter.com/projects/limemouse/scanbox-turn-... Bonus points if someone can sell this feature within a notebook/tablet stand. Modifying a tiny tower stand (https://tinytowerstand.com/ https://tinytowerstand.com/) comes to mind.
- tpetry 7y ago
  That‘s a really cool idea, does not need much space when not used :)

trevyn 7y ago

Just cut a slit the shape of the cardboard profile in the top of the pasta box and shove the cardboard in?

zaroth 7y ago
You would still need to fill the box with something heavier than pasta.

kohtatsu 7y ago

Re. orientation: the phone shouldn't be trying to determine landscape/portrait when flat; it should gracefully keep the previous state for at least a dozen degrees. On my 11 Pro it doesn't change until ~40 degrees of attitude.

ckdarby 7y ago
In Android there's an option to lock orientation.
- yed 7y ago
  There's one in iOS as well.
  - lotsofpulp 7y ago
    Only for portrait mode. Never made sense to me why they only allow locking in one orientation and not landscape.
    - gtufano 7y ago
      It's "lock rotation", not "lock portrait". If you have the device in landscape when you lock it, it will lock in landscape.
      - lotsofpulp 7y ago
        I just did it on an iphone 6S Plus and an iPhone XS both with ios13+, and while in landscape, if I press lock rotation, it changes to portrait and then locks it. I’ve experienced this since iPhone 3G or iPhone 4, so I assume this is how they have designed it. https://discussions.apple.com/thread/8237975 https://discussions.apple.com/thread/8237975 This website shows a workaround for it: https://www.igeeksblog.com/how-to-lock-rotation-in-iphone-landscape-mode/ https://www.igeeksblog.com/how-to-lock-rotation-in-iphone-la...
      - manigandham 7y ago

montroser 7y ago

In these situations where you're taking a photograph of writing or a diagram on a piece of paper, it can be surprisingly tricky to get rid of the shading from the lighting conditions and be left with just the content on the page in high contrast. This explanation nails how to do it though: http://www.imagemagick.org/Usage/compose/#divide http://www.imagemagick.org/Usage/compose/#divide Divide a blurred copy by the original and you end up with effectively an adaptive-normalize filter where the result is nice and clear with the shadows and uneven lighting left behind. Also though, there are tools like https://miro.com https://miro.com and https://beta.plectica.com https://beta.plectica.com which kinda make this obsolete for many common use cases.

tehlike 7y ago
Google has photoscan app on Android that is pretty good.
joshvm 7y ago
Most commercial solutions solve this by using bright illumination from both sides to avoid shadows. In a pinch a couple of led under-cupboard light strips off would probably work. Something like: https://www.interactive-education.co.uk/product/visualisers/genee-vision-6100/ https://www.interactive-education.co.uk/product/visualisers/... It's almost always easier to control the illumination in the first place rather than fix it in post.
- HarryHirsch 7y ago
  In the real world the "bright illumination from both sides" solution is called a makeup mirror. Just get one of those and glue the phone to it.
dharma1 7y ago
Notes has a good document scanner on iOS - https://support.apple.com/en-us/HT210336 https://support.apple.com/en-us/HT210336 Google Photoscan mentioned by someone else is also great, it's available on iOS and Android It takes a series of photos, and guides you to move the phone as the document is illuminated from different angles by the led flash. It then blends them for optimal result to eliminate glare

exikyut 7y ago

> frame rate, encoder quality. Especially low end phones do not have enough power to encode highly variable input (see previous bullet), resulting in unreadable images. An encoder setting for low frame rate (e.g. 1-2FPS) and high quality would be invaluable for such an use case. Ways to go even better: - Don't use an "<x>FPS" based model of continuous transmission - the paper isn't always updating by default - In extremely low-bandwidth situations, never update while there's a hand in the frame; only update once the paper image settles again - Get all fancy with feature detection and draw buttons on the corner of the paper; one of these could be "update" and the device would beep to acknowledge the frame had changed. This is actually practical as not everyone has bluetooth keyboards, audio-based commands would be distracting, and tapping onscreen buttons would nudge the device - Perform frame border analysis and automatically crop and rotate the actual paper as it's moved around

Cherian 7y ago

I don’t want to look like promotional, but recently a professor used an Osmo reflector (https://twitter.com/romps/status/1237617042338897921?s=12 https://twitter.com/romps/status/1237617042338897921?s=12) to project class notes and it caught on with teachers. A team worked through the weekend and released a free app to make this super easy (https://twitter.com/PlayOsmo/status/1241152565083090947 https://twitter.com/PlayOsmo/status/1241152565083090947). While the base + reflector is not free, if you already have an Osmo game at home, you can reuse that.

jedberg 7y ago
OMG, this is exactly what I needed! I've been working from home for five years, and the one big missing piece was "whiteboarding". I even have an extra Osmo reflector and base! Now I just have to convince the kids to stop playing Osmo long enough so that I can use it. :) Thank you!

robbrown451 7y ago

When I use my phone camera to copy documents or especially photographs (i.e. old school printed-on-paper paper photos), I've found the most useful thing is to light it with the sun. You can do it next to a window if the sun is shining in (best the window is clean), or I just do it on my porch if it isn't windy. They come out with excellent quality...I have found it does better than even scanning them (which takes much longer) Obviously, the sun should be at enough of an angle so it won't cause glare. You can try to position it so the sky isn't reflecting in the photo, but honestly the effect of that is going to be miniscule because the sun is so much brighter. And of course, if you have to do it when the sun isn't out, you can make do with whatever lighting you have, but the quality won't be as good from my experience. I've done this for family photos from ages ago, and it wasn't a problem to wait for some sunshine.

martin-adams 7y ago
If you have to use indoor lighting, find a flat object to lay it on, then tilt it parallel to the light so your hand is less likely to cast a shadow.

Hnrobert42 7y ago

Off topic, but as OP is from the .it TLD, it’s interesting to note OP prefers riga pasta, especially in light of this article: https://qz.com/1811768/coronavirus-lockdown-ignites-an-old-italian-debate-its-about-pasta-of-course/ https://qz.com/1811768/coronavirus-lockdown-ignites-an-old-i...

number6 7y ago
Related Note: Referring to this method as poor man's method while using a pack of pasta while pasta is as hard to get as TP. Pun intended?
martopix 7y ago
(unipi.it: University of Pisa)
- martopix 7y ago
  Also, smooth pasta is embarassing.
  - stclaus 7y ago
    that's why they're using it for something else than meals :)

mhenr18 7y ago

I couldn't resist trying this and making some more detailed instructions for getting better images out of iOS. Turns out that you can get fairly good results without any fancy software. https://mhenr18.github.io/improvised-document-camera/ https://mhenr18.github.io/improvised-document-camera/

Aardwolf 7y ago

"Apollo 13 style camera stand" That name sounds amazing for being a box of pasta!

wallflower 7y ago

If you want to upgrade from DIY, Ipevo sells a line of document cameras that start at $99. Some are not as expensive as dedicated, stand alone classroom document cameras because they require a computer to operate. https://www.ipevo.com/products https://www.ipevo.com/products

deleted 7y ago

[deleted]

mkl 7y ago

A stack of books with a couple of rulers under the top one works better - it's height-adjustable. Moving a bit further up the quality ladder, I've just built myself a solid laptop/monitor stand out of plywood, and I'm going to attach a strut sticking out the back to hold up a webcam-as-document-camera and (when it arrives) an LED ring light. There are actually a whole lot of cheap products based around the phone-as-document-camera idea, e.g. https://www.aliexpress.com/item/4000309823825.html https://www.aliexpress.com/item/4000309823825.html, a stand, phone holder, and ring light.

klingonopera 7y ago

> "With so many people and students around the world working from home, we really need some easy to deploy shared whiteboard solution. This is especially important for pre-college students who may not have access to high end hardware." Just add a new mode to videoconferencing, where both parties get a white screen and both can start drawing and the resulting image stays in sync on both clients? (I feel like this solution is so obvious, I'm about to fly out a window - what am I missing?) Sounds like way less work for those already developing videoconferencing apps than to deploy stand-alone solutions in addition to that. In fact, phones could do good just having a "scratchpad" as a "phone-variant" of Notepad and/or Paint. It helps to quickly draw something, a simple sketch, or communication with deaf people or those who don't share a common language. It's sad to see the state of bloatware on phones and not seeing many useful things. It took ages for them to add the torch/flashlight feature as a standard into the OS, back in the day, we needed to use apps to get that done, so I think it's probably symptomatic of the entire industry. Hell, it's no wonder Apple can get away selling their expensive stuff, the others aren't really setting the bar high enough...

lrizzo 7y ago
>> "With so many people and students around the world working from home, we really need some easy to deploy shared whiteboard solution. This is especially important for pre-college students who may not have access to high end hardware." >Just add a new mode to videoconferencing, where both parties get a white screen and both can start drawing and the resulting image stays in sync on both clients? (I feel like this solution is so obvious, I'm about to fly out a window - what am I missing?) Author here. There have been a few proposals in this space for the past 25 years including hangouts extensions, using a virtual camera that just exports the screen (if people remember the old mbone tools wb and vic; I myself wrote an extension to replace the camera with a snapshot from a configurable region of the X screen), and my own shared whiteboard which gives parties a shared screen that they can edit modify replay ... http://info.iet.unipi.it/~luigi/wb/ http://info.iet.unipi.it/~luigi/wb/ There are two main reasons (in my opinion) why this space has been neglected: - almost nothing matches the convenience, speed and _resolution_ of writing and drawing with an actual pen. Pads with sufficient resolution and decent lag are only appearing now, and they are fragile and expensive. Graphic tablets are cheap but lack the visual feedback and looking at the output on the screen still has significant latency. They are moderately usable, but takes time to get used to them, and you need a real 10+in screen to use them effectively. Using a finger or a conductive pen on a phone screen is only good for small sketches, not for writing longer sentences or formulas. - the main users of such products would be non commercial entities (pre-college schools, students) so there are no paying customers. Even at college level lectures are increasingly based on slides prepared in advance. Businesses, of course, use slides or meet in person, and the whiteboard style of collaboration is generally done in person. Social distancing now may actually create more use cases and perhaps returns (in terms of actual money or social appreciation) that stimulate software solutions to appear. The Apollo13 problem still stands: even if we had good and cheap technology for writing, at this time it would be impossible to build and sell such products to customers, so we have to find solutions that use hardware already in possession of the users.

sandreas 7y ago

Thank you HN for this article and the comments. Years ago I wrote a little java command line tool based on BoofCV (Pure Java CV lib - https://boofcv.org/ https://boofcv.org/), tess4j (tesseract) and PDFBox to create PDFs with OCR and invisible Text Layer, to make its contents searchable like the OCR Option in PDF X Change Viewer. I used a combination of Thresholding and deskewing to improve my Documents (e.g. Sauvola, Nick) - see https://boofcv.org/index.php?title=Example_Thresholding https://boofcv.org/index.php?title=Example_Thresholding Now I plan to restore and improve the old code and provide it as open source solution :-) Hope the code still somewhere on my old harddisks.

bitfhacker 7y ago

I use a pile of book with the mobile phone on the top of them. For photos I use CamScanner free because it crops automatically the photo, auto contrast them and save multiple pages as a pdf.

zvonimirs 7y ago

Hi guys, founder of AWW (https://awwapp.com https://awwapp.com) here. AWW is one of the first and simplest online whiteboard on the market. Check us out. Also, for schools, we are giving free premium until the end of the COVID-19 situation. Stay safe everyone.

timtas 7y ago

Fine until you eat up all your other pasta. Then where are you? Well, I guess at that point you have bigger problems. :)