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Tuesday, November 29, 2011

Resistor Photo ID

I shipped a new iPhone app a few weeks ago - "Resistor Photo ID"

It uses your iPhone's camera to help identify resistor values.

(check out my other iPhone apps here)

I specifically developed it with color blind people (like myself) in mind - who can't successfully ID resistors even if they take the time to learn the color codes.

Click here to get it from the Apple App Store (currently free!).

Using resistor ID is easy:

1. Take a photo of a 4-band resistor using the app

2. Drag the numbered bars over the corresponding resistor bands

3. Resistor Photo ID provides you with the resistance and tolerance of the resistor!

If for any reason Resistor Photo ID doesn't detect the correct color for a band - you can easily override it.

Monday, November 28, 2011

123D Catch

I've been playing with Autodesk's 123D "Catch"

It's a free app that transforms sequences of still images into a 3d model of an object.

It does the processing "in the cloud" - in conjunction with a client-side application.

Here's a sample video I did:

It is -very- beta (really alpha) - has some probs - but is still quite cool.

Take a lot of shots in a continuous sweep around the object
Don't jump around when shooting
Try to get lots of overlap between photos (move around the object maybe 15 degrees per shot)
After you've rotated around the object once - you can move a bit higher / closer on a second pass around for more detail
Somewhere between 25-60 shots total seems optimal
Try to keep lighting constant
Don't use a flash or HDR

I've generally found that Catch either comes up with a good model the first time around or it doesn't. I have had very bad luck trying to manually adjust things if Catch didn't figure it all out the first time. My advice is if you didn't get good results - redo the photo shoot.

More notes:
Couldn't get direct youtube upload to work
Video export seems somewhat broken (most codecs resulted in unplayable videos)
Was able to get a useable export by choosing "Raw" as the video codec - then knocking the resolution down to 640x360.