4 ms·

Wouldn't web scraping be possible by taking screenshots of the rendered pages and then reading them with OCR?

by svdr 3y ago

ekianjo 3y ago
probably very inefficient as it would depend on layout a lot too
- cush 3y ago
  As inefficient as parsing heap snapshots?
  - brigadier132 3y ago
    Much more
deleted 3y ago
[deleted]
spaniard89277 3y ago
You'll be spending resources on LLMs like crazy. Possible but very messy IMO.
- anamexis 3y ago
  You don't need LLMs for OCR.
  - ekianjo 3y ago
    OCR does not get you the names of the classes in a DOM
  - spaniard89277 3y ago
    No but maybe you want to do something with the ocr output.
simonw 3y ago
If you just want the text there are other ways to do that. You could dump out document.body.innerText for example - here's how to do that with https://shot-scraper.datasette.io/en/stable/javascript.html https://shot-scraper.datasette.io/en/stable/javascript.html shot-scraper javascript youtube.com 'document.body.innerText' -r Output: https://gist.github.com/simonw/f497c90ca717006d0ee286ab086fbdde https://gist.github.com/simonw/f497c90ca717006d0ee286ab086fb... Or access the accessibility tree of the page using https://shot-scraper.datasette.io/en/stable/accessibility.html https://shot-scraper.datasette.io/en/stable/accessibility.ht... shot-scraper accessibility youtube.com Output here: https://gist.github.com/simonw/5174380dcd8c979af02e3dd74051a9c9 https://gist.github.com/simonw/5174380dcd8c979af02e3dd74051a...
- lelandfe 3y ago
  Of course, if the document is using the outline in unexpected ways, you'll run into trouble. Consider Facebook infamously splitting "Advertisement" into multiple spans to avoid tripping ad blockers.
michaelt 3y ago
Although you'd imagine screenshots would be easy to OCR reliably, it's not guaranteed to get everything correct. It's not like you can rely on a dictionary to confirm you've correctly OCRed a post by "@4EyedJediO" - who knows if that's an O or a 0 at the end? And if you're OCRing the title and view count of a youtube video, for example, you've got to take the page layout into account because there's a recommendations sidebar full of other titles with different view counts.
- plorntus 3y ago
  I guess you'd get better results if you knew the font the site uses (which in many cases you could figure it out pretty quickly) or even just override every font with your own.
berkle4455 3y ago
Much of the content worth scraping isn't rendered on the screen.
- zffr 3y ago
  Do you have any examples? I haven’t experienced this myself
  - throwawayadvsec 3y ago
    URL, images, stuff shown after you click on a button...
is_true 3y ago
Yes, it's possible. We do this for TV shows.

Wouldn't web scraping be possible by taking screenshots of the rendered pages and then reading them with OCR?

by svdr 3y ago

Wouldn't web scraping be possible by taking screenshots of the rendered pages and then reading them with OCR?

ekianjo 3y ago

probably very inefficient as it would depend on layout a lot too

cush 3y ago
As inefficient as parsing heap snapshots?
- brigadier132 3y ago
  Much more

deleted 3y ago

[deleted]

spaniard89277 3y ago

You'll be spending resources on LLMs like crazy. Possible but very messy IMO.

anamexis 3y ago
You don't need LLMs for OCR.
- ekianjo 3y ago
  OCR does not get you the names of the classes in a DOM
- spaniard89277 3y ago
  No but maybe you want to do something with the ocr output.

simonw 3y ago

If you just want the text there are other ways to do that. You could dump out document.body.innerText for example - here's how to do that with https://shot-scraper.datasette.io/en/stable/javascript.html https://shot-scraper.datasette.io/en/stable/javascript.html shot-scraper javascript youtube.com 'document.body.innerText' -r Output: https://gist.github.com/simonw/f497c90ca717006d0ee286ab086fbdde https://gist.github.com/simonw/f497c90ca717006d0ee286ab086fb... Or access the accessibility tree of the page using https://shot-scraper.datasette.io/en/stable/accessibility.html https://shot-scraper.datasette.io/en/stable/accessibility.ht... shot-scraper accessibility youtube.com Output here: https://gist.github.com/simonw/5174380dcd8c979af02e3dd74051a9c9 https://gist.github.com/simonw/5174380dcd8c979af02e3dd74051a...

lelandfe 3y ago
Of course, if the document is using the outline in unexpected ways, you'll run into trouble. Consider Facebook infamously splitting "Advertisement" into multiple spans to avoid tripping ad blockers.

michaelt 3y ago

Although you'd imagine screenshots would be easy to OCR reliably, it's not guaranteed to get everything correct. It's not like you can rely on a dictionary to confirm you've correctly OCRed a post by "@4EyedJediO" - who knows if that's an O or a 0 at the end? And if you're OCRing the title and view count of a youtube video, for example, you've got to take the page layout into account because there's a recommendations sidebar full of other titles with different view counts.

plorntus 3y ago
I guess you'd get better results if you knew the font the site uses (which in many cases you could figure it out pretty quickly) or even just override every font with your own.

berkle4455 3y ago

Much of the content worth scraping isn't rendered on the screen.

zffr 3y ago
Do you have any examples? I haven’t experienced this myself
- throwawayadvsec 3y ago
  URL, images, stuff shown after you click on a button...

is_true 3y ago

Yes, it's possible. We do this for TV shows.