From 3aaffefc878db38597207e2ad1e2bc62e25f6914 Mon Sep 17 00:00:00 2001 From: Chris Hodapp Date: Wed, 5 Oct 2016 15:33:05 -0400 Subject: [PATCH] Pi pan tilt, first two parts: fixed some links, updated titles --- posts/2016-09-25-pi-pan-tilt-1.md | 4 ++-- posts/2016-10-04-pi-pan-tilt-2.md | 33 ++++++++++++++----------------- 2 files changed, 17 insertions(+), 20 deletions(-) diff --git a/posts/2016-09-25-pi-pan-tilt-1.md b/posts/2016-09-25-pi-pan-tilt-1.md index 0744156..1a798fd 100644 --- a/posts/2016-09-25-pi-pan-tilt-1.md +++ b/posts/2016-09-25-pi-pan-tilt-1.md @@ -1,5 +1,5 @@ --- -title: Raspberry Pi pan-tilt mount for huge images, part 1 +title: Pi pan-tilt for huge images, part 1: introduction author: Chris Hodapp date: September 23, 2016 tags: photography, electronics, raspberrypi @@ -91,7 +91,7 @@ produce: [![](http://i.imgur.com/zwIJpFn.jpg){width=100%}](http://i.imgur.com/zwIJpFn.jpg) -More posts will follow soon on this! +Follow along to [part 2](./2016-10-04-pi-pan-tilt-2.html). [cs6475]: https://www.omscs.gatech.edu/cs-6475-computational-photography [ArduCam]: http://www.arducam.com/camera-modules/raspberrypi-camera/ diff --git a/posts/2016-10-04-pi-pan-tilt-2.md b/posts/2016-10-04-pi-pan-tilt-2.md index 80e0af1..ae10b19 100644 --- a/posts/2016-10-04-pi-pan-tilt-2.md +++ b/posts/2016-10-04-pi-pan-tilt-2.md @@ -1,5 +1,5 @@ --- -title: Raspberry Pi pan-tilt mount for huge images, part 2 +title: Pi pan-tilt for huge images, part 2: Hugin & PanoTools integration author: Chris Hodapp date: October 4, 2016 tags: photography, electronics, raspberrypi @@ -44,20 +44,22 @@ really curious). We may end up with images for which optimization can't really improve the estimated position, and here a guess based on where we think the stepper motors were is much better than nothing. -If we look at the [PTO file format][pto] (which Hugin & PanoTools -use), it has pitch, yaw, and roll for each image. Pitch and yaw are -precisely the axes in which the steppers move the camera (recall the -pictures of the rig from the last post); the roll axis is how the -camera has been rotated. We need to know the lens's angle of view -too, but as with other parameters it's okay to just guess and let the -optimization fine-tune it. The nominal focal length probably won't be -exact anyhow. +If we look at the [PTO file format][pto] (which Hugin & PanoTools use) +in its i-lines section, it has pitch, yaw, and roll for each image. +Pitch and yaw are precisely the axes in which the steppers move the +camera (recall the pictures of the rig from the last post); the roll +axis is how the camera has been rotated. We need to know the lens's +angle of view too, but as with other parameters it's okay to just +guess and let the optimization fine-tune it. The nominal focal length +probably won't be exact anyhow. Helpfully, PanoTools provides tools like `pto_gen` and `pto_var`, and I use these in my script to generate a basic .pto file from the 2D -grid in which I shot images. The only real conversion needed is to -convert steps to degrees, which for these steppers means using 360 / -64 / 63.63895 = about 0.0884, according to [this][steps]. +grid in which I shot images. All that's needed is to add up the steps +taken to reach each shot, convert steps to degrees, which for these +steppers means using 360 / 64 / 63.63895 = about 0.0884 (according to +[this][steps]), and making sure that the positive and negative degrees +correspond to the right direction in each axis. With no refining, tweaking, or optimization, only the per-image stepper motor positions and my guess at the lens's FOV, here is how @@ -110,11 +112,6 @@ However, you can look up close and see how well the details came through - which I find pretty impressive for cheap optics and a cheap sensor. -TODO: - -- This was done completely with a raw workflow, blah blah blah -- How did I wire the steppers, vs. how does Hugin see things? - [ArduCam]: http://www.arducam.com/camera-modules/raspberrypi-camera/ [forum-raw-images]: https://www.raspberrypi.org/forums/viewtopic.php?p=357138 [raspistill]: https://www.raspberrypi.org/documentation/raspbian/applications/camera.md @@ -129,4 +126,4 @@ TODO: [hive13]: http://hive13.org/ [projection]: http://wiki.panotools.org/Projections [szeliski]: http://szeliski.org/Book/ -[pto]: ??? +[pto]: http://hugin.sourceforge.net/docs/manual/PTOptimizer.html