Thursday, July 8, 2010

Image and imaging.

This Sunday I was fortunate to spend my 4th of July at the Vis on Mauna Kea under a clear dark sky. This time of year the Milky Way is simply gorgeous, so bright in the dark sky that people often mistake it for clouds. Sunday I finally fulfilled a wish of mine, and took a number of shots which I stitched together into a panorama of the Milky Way.

Summer Milky Way from Mauna Kea.

Again, you really need to click on this one to see. I should also mention that this is not exactly what the Milky Way looks like on Mauna Kea. Stitching the pictures together to make the panorama introduces some horrible stretching and distortions into the image, which due to the way I composed the shot is most visible just left of center, but is present everywhere to a small degree. It's very similar to the atrocities perpetrated upon geography by mapping a spherical globe onto a flat map. The picture is also not quite representative because it was made using 30-second exposures, so not everything in it is visible to the naked eye in such detail (although is is possible to get a glimpse, at least, of pretty much everything in this picture).

This picture is facing towards Hilo, the lights of which you can see on the horizon as an orange glow in the center of the picture. Although difficult to make out in the picture, you can just spot the glow of Kīlauea on the limb of Mauna Kea to its right. The center of our galaxy is located in the direction of the brightest region, in the upper-right part of the picture. The red-lit foreground comes from the low light level conditions and red lights used at the Vis.

In other unrelated news, I had major breakthrough with my job vocation yesterday, where I finished a project I'd been working fruitlessly on for almost a week in less than a day. I was tasked with creating images from the lists of data that I've been working with -- doable in principle, since the data came from (complicated) pictures in the first place, but not immediately obvious in practice.

I spent several days looking in the wrong places, before coming across a great resource, the Python Imaging Library. The night before I'd had trouble setting it up on my computer so I wasn't sure what to expect, but it went flawlessly: I was able to create my first test picture in less than 20 minutes after installing it, and had my first actual image within a few hours (most of which was spent figuring out how to map a one-dimensional list of numbers back into a two-dimensional image).

I then ran the script on all the data files, and the feeling I got while watching image files pop into existence in the folder I'd created for them was pure exhilaration. I'm sure the creators of the first digital cameras must have felt similar when they got their first images. The pictures aren't much to look at -- just extremely grainy, gray-scale images -- but knowing the exact process of their creation makes them much more interesting to me.

Well. I guess it's appropriate that this post about a digital image turned into a discussion about digital imaging. Perhaps at a later date I can share some of the more interesting pictures created by my script with you all.

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