That's so amazing to hear! It pretty much flew under the company radar--most people didn't find out about it until the first reviews of the Lion beta came out.
I don't think it was very common at Apple for an individual engineer to conceive, implement, and ship a feature like this. There was a general sentiment on the team of "let's do something with signatures," but we knew that very few people had scanners. We thought about touchpad input, but decided against it at the time. (That came much later, in either 10.11 or 10.12)
I was thinking, "well, almost no one has a scanner, but practically everyone using this application has a camera in their Mac." I built the initial prototype in OpenCV and then ported it to Apple's vDSP/Accelerate frameworks.
My favorite detail, which doesn't seem to be present in 10.12, is that you could just click on a horizontal line in a PDF; since I recorded the signature's offset relative to the baseline superimposed on the camera image, it would place the signature exactly on the line, with descenders nicely descending.
I've since moved on from macOS/iOS development, but I had a really positive experience at Apple. Met so many amazingly talented people there.
Thanks! It's one of my favorite features in Preview.
I used to hate PDFs before getting a Mac, but the first-class support in Preview, with features like that (along with the ability to tear out, reorder and attach pages) made me change my mind.
To be fair, on a Microsoft Surface you would just use your pen to sign directly on the screen which is much more natural. It doesn't make any sense to me that Steve Jobs was so anti-pen, while also pushing for intuitive interaction.
Perhaps if someone added electromagnetic traction so that the screen provided some push-back to the pen tip, it would seem "natural," but as things are now, my on-screen signature is as good as a chicken scratch.
Providing a pen is an excuse to leave controls that are too small to use with your fingers. So while Windows now has a Touch mode where many controls are larger, many others which are also essential to using the system are tiny and hard or impossible to use by touch. That is what Steve Jobs was trying (successfully) to avoid.
That's how it works on an iPad. Touch/pen interfaces are terrible on the PC/Laptop form factor though. At best you gimp your desktop metaphor so it's functional with touch, at worst you have an unusable touch interface.
I think he was anti the crappy pens and digitising systems available at the time, the requirement to have a pen to use the device at all and the poor interface designs they encouraged.
Thanks! I use that feature almost every day. We try to be a paperless home so being able to sign PDF forms and return them without printing is one of my single favourite features of OSX. We even bought our house using that feature for all parties to sign it around my MacBook.
Thanks. It's a great feature, and one that adds a lot to the overall Mac OS experience. It's too bad that most people have no idea that it exists, since no other OS has it. But for those who know, it's a huge time and paper saver. Excellent work.
I just found out about this feature a couple of days ago, after being a Mac user for 4 years. My first thought was it's incredibly neat - shame I didn't learn about it before.