Thursday, March 20, 2014

Comment: What's that thing on the horizon?

SearchResearchers are doing pretty well.  Nice job so far. 

For readers who haven't had the chance to work on it yet, let me give you a bit of a clue. 

Here are a couple of images that I'm zoomed in for you. 

Figure 1: The image zoomed in. 

In this image you can see the "white thing" much more accurately.  You can also, in this view, see the trees a bit more clearly.  Regular readers might recognize this scene with the trees.  

Once I zzome in like this, I NOW see that white line of... something.  It's kind of lump and irregular, and I have no idea what it could be.  (Truthfully.)  Will have to check it out.  

All I did in these images was to push the scale (in this case I used Apple's Preview tool, but you can use image manipulation tool like Photoshop or Gimp).  Be careful, though, that the package you use doesn't smooth the image too much as you zoom.  You want to be able to see the actual pixels when you're zoomed way in.  

Figure 2: The image zoomed to the point of seeing the pixels.

From this angle at this zoom, it looks like a boat.  (But it's not Noah's ark; trust me on this.)  

I'm looking for a good handbook on photo interpretation that I can point everyone to, but I'm not having much luck.  The books I've been finding are all either not-available online, or were written pre-2000 (and therefore have slightly old examples and no mention of Google resources at all).  The number of available images that have come available in the past 10 years should be causing all of the photo interpretation books to be re-written!  

So if you know of any good ones, let me know.  We'll post it in the blog for everyone to learn from. 

Keep searching! 


  1. "Once I zzome in like this, I NOW see that white line of... something. It's kind of lump and irregular, and I have no idea what it could be. (Truthfully.) Will have to check it out. "
    I've been mistaken multiple times, but isn't that the Junipero Serra/I-280 with traffic?
    starts right around Alpine Rd./Sandhill -
    no book suggestion, but this might be of some value?

  2. Since these comments don’t pertain to the original challenge I’ve placed them here. However your comment on the “white line” from Google Maps I would say its traffic on the #280 Junipero Serra Freeway.

    I have the photo editor “Pixlr Editor” which is free online and having used Photoshop a lot in the years ago I can tell you this free app is very good. I did zoom in not quite as much as Dr. Dan using this app before getting visible pixels. I’m using Chromebook which doesn’t have the best screen. I need to qualify that I think the app for Chromebook is quite good. The Android has the same zooming ability but the app is very basic.

    What I would like to see is a combination of mapping with images so we could not only get the coordinates of the photographer’s location but a compass bearing and ideally the ability to lay a grid over the photo giving us map coordinates for the area. I know you can take say a “you are here” map you may find on a trail and overlay that in google earth to create your own custom map. So the next step is laying the mapping info via gridlines on images. Or is this already in existence and I’m just not aware of it.

  3. This topic is very interesting. I don't know anything so I'm learning with each post that is made.

    Free Map Tools is one site that I found searching for measuring distances on an image. Looks interesting and I noticed Google mentions it on Google Maps Advanced features.

    One question, Zoom is the same as re-scale? Right? I'm learning to use Picasa and it is better if I understand the terms right. Thanks!

    1. Ramón Buenos Días! When I think of image scaling I think of resizing but its been 10 years. Here's a link that explains it as it applies to digital photography. I would go into more details but I might confuse myself and you.

    2. Thanks Rosemary and Remmij for the links.

  4. Can you elaborate on what you mean by photo interpretation? Are you referring to online photography? Authentic vs manipulated? Using software to aid in analysis? Photo elements of light and shadows, colors, and angles? Or perhaps all of the above.

  5. … not directly relevant, but may be of interest…
    a different level of image interpretation:
    and in the private sphere: