Automatic Exposure Compensation Testing for the Pi Camera #piday #raspberrypi @Raspberry_Pi
Sometimes taking a look at the testing procedures for developing a project can be as useful as the study of the resulting project. Check out Alex Eames’s detailed documentation for how he has been testing the Pi Camera module towards the construction of a RasPiCamcorder.
In the 4 weeks since the Pi camera came out, I’ve spent a fair amount of time testing and fiddling with different things. I’ve also made two RasPiCamcorders – I hope to document the Mk2 version soon. It’s the reason I haven’t blogged much in the last week. I’ve been working on the hardware and software for it.
One thing I hadn’t done until this week was test out the various settings for exposure compensation and white balance. Previously, I’d only used the automatic settings, which work pretty well. But there are some circumstances where it’s nice to be able to override these manually.
I want a video demo
I wanted to make a video showing each of the settings. But to do that for each of -10 to +10 ev settings and then edit the video seemed like a right royal nuisance. Wouldn’t it be good if we had a computer to do the repetitive boring bit for us? Hold on, we do. 😉
So I wrote a Python program to shoot a short 10s clip at each of the 21 different settings. That was the easy bit.
But I’ve still got to convert them from .h264 to something I can edit. So, using MP4Box, we’re doing that programmatically as well.
Wouldn’t it be nice if we could trim and edit programmatically too?
For each clip, during the first few frames, the camera is setting its exposure levels. So I wanted to be able to trim off the start from each clip and then put them all together in sequence.
I wanted to do all this, along with conversion and filming in one Python program. (This is how software applications grow – just keep adding features.)
8-6-2021 (August 6, 2021) is the Snakiest day of the year and it’s also this year’s CircuitPython Day! The day highlights all things CircuitPython and Python on Hardware. See you there!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !
“Sometimes taking a look at the testing procedures for developing a project can be as useful as the study of the resulting project.”
That was rather kindly put. 😉
The results were quite boring in this case, but getting there was quite a lot of fun, and I learnt some useful things, like how to shoot, cut up and reassemble video clips programmatically with the Pi.