A Return to Stereograms

4 April 2018

I have mentioned working on stereograms previously. These last couple of weeks have seen me focused on them.

Stereogram created from drone video taken at Wickahoney. See text for details.

Most that I have done before are close-ups, if you will, or portrait oriented.

I wanted to play with stereograms some more, this time focusing on landscapes. My goals were, first, to get them working consistently and second to hopefully work out any rules unique to stereograms.

In my mind’s eye, I remember sitting on the floor at my grandparent’s with a big box of stereograms and a now antique viewer. I would pick out a card with it’s two slides, read the caption, drop it in the holder, and clap the stereoscope to my face. I remember being fascinated how I could see a 3D version of a scene and how it contrasted from the pictures on the wall.

More, I remember most of them were landscapes.

Now, I’ll grant you my memories of those images are likely rose colored by time and they may not have been as fantastically 3D as I seem to remember. Most indubitably, though, there were hundreds of landscapes and not so many of flowers, people, or objects.

My goal in this recent project was to create valid 3D landscape stereograms. I also needed to work out what the limitations were, and how best to create a pleasing image that was also 3D.

Like this one:

One of the spots that overlooks Swan Falls and the Snake River Canyon, looking downstream from the dam.

Or this one, where the red rock formation just pops out at you:

Looking at Swan Falls Dam and the Snake River Canyon. The red rock is very prominent in the foreground.

What are the rules?

Aside from standard landscape photography composition “rules” I felt there must be some additional guidelines that would drive the composition.

As it turns out, there are, and there aren’t.

One of the things that you need to keep in mind when creating stereograms is:

  1. Take a picture of your subject. Remember where the center of your picture is on the subject.
  2. Take a step to the left. I usually stand with my feet just more than shoulder width apart. After taking the first picture, I move my right foot to touch my left foot then move the left foot so I am again standing with feet apart.
  3. Aim the camera at the exact same point on the subject as before.
  4. Take another picture.

That is my way of getting paired, handheld pictures. The first picture taken thus becomes the “right” picture (as in taken from the right) and the second becomes the “left” picture. The key to assembling the stereogram is the right picture goes on the left side and the left picture goes on the right side.

You can, of course, do it stepping to the left instead. In this case the first image becomes the left picture and the second becomes the right picture. No biggie, just get into the habit of doing it the same way each time.

There’s times a question arises whether or not the middle and far parts of the photograph actually show as 3D. Sometimes they do, sometimes they don’t. Sometimes they work if you have some decent foreground detail, other times you don’t need that foreground to make it work.

Willow Creek, off Black’s Creek Road. Notice the apparent differences in 3D impact in this compared to the Swan Falls stereograms.

And then, there’s the issue of anything that’s moving…that’s likely to produce “ghosts”, faint or translucent objects in the photo. Your main scene, the one you want to see in 3D, has to be still. Trees moving in the wind, clouds passing by overhead, cars on the road, people moving…all those and more need to be avoided.

One way to avoid natural movements such as clouds and water ripples is to use a long exposure time. That way, things get “smudged” smooth. Ripples on water, for example, become a soft flat surface and clouds become featureless.

Interestingly enough, I have one stereogram (below) where the two angles are such that one shows the parked truck and the other doesn’t, and yet the truck is solid in the stereogram view. It’s not a translucent ghost due to being in only one of the paired images. Yet another stereogram I’ve done freezes a car in one picture but it’s not in the other and this time it shows as a ghost car. Go figure. That’s what I mean about “there are and there aren’t additional guidelines.” More likely I haven’t figured them out yet.

Notice how the black truck is in one image but not the other, yet still comes through in the stereogram as solid, not as a ghost image.

By the way, the Wickahoney stereograms were all pulled from a video created by orbiting my DJI Phantom 4 around the midpoint of the ruins. You do remember that a video is merely a string of still images played back rapidly? Each pair, in this case, were pulled from about 1 second apart, e.g. one would be from 13 seconds into the video, and the second of the pair would be from 14 seconds into the video. When doing this, creating a stereogram from a video, you want to be sure the video still image isn’t blurry due to the drone moving too fast, to continue this example.

Stereogram from Wickahoney drone video.

One thing I did discover is that if you use a zoom or telephoto lens to enlarge something in the distance and make it part of your foreground or the middle distance in the photograph, you have to displace the camera location much more than a single step to one side. A problem I encountered was I could properly displace the distant solitary tree but the mountains behind it shifted significantly. They shifted enough that even though I could get the tree to be reasonably 3D, the more distant mountains were blurry.

A wide angle lens, though, works great and lets you really bring in some foreground:

Snake River Canyon from an overlook at Swan Falls, looking upriver from the dam.

And that’s as far as I’ve got. I’ll be going out and shooting more landscapes, as well as some closer subjects.

I think I know how to apply this technique to video as well and plan to try it with the video used to make the above Wickahoney stereograms. That’s for another time, though.

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Morse in a New Year

25 January 2018

One of the things I’ve done in the past few weeks is build a new keyboard for this computer. It’s what’s called a straight key in radio circles.

Telegraph key being used as a USB keyboard on my computer.

Yep, it’s real. And it works. I actually used it to type (key?) in some of this blog post. It’s literally just an USB cable, a Teensy 3.1, and a Morse code key. I’m going to mount the Teensy in the bottom of the board, but for now it’s on the protoboard until I get all my code changes done.

So, why? What the heck would I do that for when I have a perfectly good computer keyboard?

At the start of 2018 I was once again thinking I wanted to find a way to really make myself learn Morse Code. A way that would guarantee I would learn it.

Among other times, I want to use my mobile radio when I’m out and about but don’t have the computer with me. Normally, I use PSK-31 which is computer-to-computer via amateur radio. For that, obviously, I have to have a laptop with me. The thing is, I don’t always have one with me and sometimes I will be out in the Owyhees at a spot where I’d like to see if I can have a QSO (conversation) on the radio. No laptop, no QSO.

The obvious question is, why don’t I just sit down and learn it?

Well, I could, but I’m lazy and I know it. Also, I already know about half the alphabet and numbers and a punctuation mark or two. So, what’s the problem? It’s no fun for me just sitting and memorizing the International Morse Code. I can, but that’s boring.

I began to wonder if I could somehow replace my QWERTY keyboard with a straight key. I took the path of least resistance and started searching online to see if anyone had done something like this with an Arduino or Teensy. It turns out several people had and made their code and schematics freely available.

After studying a few of them, I zeroed in on Nomblr’s rebuild of her dad’s old telegraph key. Her code was clean and the schematic about as simple as it ever gets so I leveraged off her work. The good thing was I happened to have a Teensy 3.1 in my “hell box” (as in “where the hell is it?”).

I dug out the Teensy 3.1, connected the straight key to the Teensy, plugged the USB cable into the Teensy and the computer. For testing, I simply downloaded Nomblr’s code to the Teensy, opened up Notepad++, and tried the key. I used the programmer’s holy first test: …. . .-.. .-.. — .– — .-. .-.. -..

To my immense pleasure, the letters started showing up in Notepad++ right away: hello world.

OK, so I had to look up two of those letters. That’s the whole point. I can now use the telegraph key to write on the computer, and to do so, I have to learn the Morse code letters I don’t know. Sure, it’ll be slow for a bit here and there but over the next few days or weeks I’ll be up to speed. And I’ll have learned the International Morse Code much faster than otherwise. Much.

I have already made some tweaks to her code and am in the process of adding some extra bells and whistles that I think will be useful to me. For example, I’ve added in a couple of prosigns like CQ and SOS. Keying in SOS, for example, corresponds to pressing F1 on a QWERTY keyboard. I’ve added in the punctuation from the International Morse Code table, and I’ve set up “……..” which is Morse for “error” to mimic pressing the backspace key on a regular keyboard.

Now I’ve got a fun and productive way to learn Morse code. One that not only ensures I’ll learn it, but also lets me practice sending and have fun doing so.

Soon, I’ll be on the airwaves with CW.

Future tweaks to this setup include adding a way to adjust the words-per-minute of the program. Currently it’s hard-coded and to change it to work smoothly with a faster or slower WPM I have to modify the code and dump it to the Teensy. Not difficult, but also not ideal, especially as my speed improves.

I do want to increase my speed, but one caveat is that I need to ensure that I don’t send faster than I can receive. For that reason, among others, another mod is to add a display to show what my actual WPM is as I use the key.

As to why a straight key instead of an iambic paddle…I’m of German descent, which gives me a Stubborn bonus of +4. 😉

Zombie Ramblings

22 November 2017

Right up front, let’s get one thing clear.

This post is MY ramblings, not some dogma, beliefs, laws, or anything serious. Just fun ramblings and musings by yours truly. Got it?

My wife is into and watching the US TV show, “Walking Dead.” I’m not all that into it, but I watch it with her from time to time when I’m not reading or doing something else. To me, watching this show is like reading Westerns…they do the same thing over and over: split up, wander, survive, link up, fight with other groups, repeat. She’s into the people, I’m meh on it.

For those of you wondering, I’ve read a couple Westerns. Some are different, but the vast majority of them are similar except for the type of horse, the horse’s name, the guy’s name, the girl’s name, and the name of the town.

My XYL (that’s ham-speak for wife) and I have had some fun discussions about zombies, though. That’s where the rest of this blog comes in.

Enjoy! Remember, these are just my brain wandering and musing.

One of the ladies had a baby and at one point feared she was going to be stillborn. Apparently, everyone’s infected so if they die they turn into zombies. We wound up talking about if the baby turned into a zombie as a result of that. There were some funny and creepy results of that discussion, such as…

  1. The baby has no teeth, so it’d have to gum it’s way out of the mom.
  2. Going by the way the infection is able to take over animating the body when the brain is destroyed, once out the zombie baby would be promptly up and shuffling, arms out, growling (albeit high pitched and not very loud). If it caught you, it’d promptly set to gumming you. This whole aspect is hilariously creepy in my mind.

Since the zombies lately all seem to be infected, excepting of course those zombies pulled up by voodoo and other such means, can zombies starve to death? They don’t eat each other, and when there’s no more fresh meat around…do they hibernate and slowly decompose? I suppose they could live a long time, like various bugs, fish, lizards, etc. that are comatose for years in ice, dried mud, and so forth until conditions return to favorable for them to live again. But with the bodies so obviously decomposing as soon as they turn I can see the infection starving to death. Especially once the host bodies are gone.

Supposedly, the virus in “Walking Dead” destroys the brain and takes over animating the corpse by taking control via the top of the spinal system. So, how does a poke in the head kill them, and how does cutting off their head at the neck as often as not result in a still animated body and head, only separated? Yet other times, cutting off the head seems to kill the zombie. Hmmm.

When the humans die, say of their wounds, a disease, starvation, whatever, out in the countryside, since they turn so fast into zombies, it must drive those circling buzzards nuts. I can just see it: “Hey, Al! There’s a dead body down there! Let’s eat! Oh, wait, it’s up again. What’s up with that, anyway, Al? How’s a buzzard supposed to know any more?”

The zombies, when they walk, lift up their feet maybe 3 inches at most. As often as not they just shuffle their feet along the surface. Now suppose someone loses their leg, by accident or deliberately as happened. Further suppose they have to make their own. After all, prosthesis aren’t likely to be readily available. The most likely result is…a good, old peg leg.

Now picture the person killed. He or she turns into a zombie with a peg leg. Shuffling along, the peg leg goes into a gopher, ground squirrel, rabbit, whatever hole. Since the zombie doesn’t lift it’s foot up, just shuffles along, that peg leg isn’t going to be coming out of the hole any time soon. How long do you think that zombie is going to be walking in a circle around it’s peg leg?

For that matter, if two zombies are approaching each other and collide, if they somehow get stuck together (I can think of several ways), will they forever shuffle around each other on that one spot?

Ah, well. Those were fun to think about. I’m sure people will come up with perfectly valid excuses and workarounds but I’m not into zombies enough to care, really. I’m just having fun with what little I know and funny circumstances I can come up with.

Here’s one for you.

What if only a certain group of people turned into zombies and instead of craving brains and hot flesh, they craved doing to other people whatever their profession was. Maybe doing that would also turn those people into zombies, too, just to keep things “real”. Heh! OK, so what profession would be the funniest as a zombie?

Chefs are too much like current zombies, they’d try and slice and dice you and serve you up. Mechanics could be interesting. Beauticians? Mimes? Gah! Can you imagine a world of mimes?!?! You’d never hear them coming, though! Dancers?

And please, just leave all this as the thought experiments they are. No need to try and create zombies just to answer the above for once and all. The human race will thank you for your restraint.