Review: Hugin (free and open source software)

Posted on February 11, 2012

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While fishing around looking for some open source software to use for a system administration task on Linux, I came across an article on “Hugin” software used to stitch images together into a panorama. This review is on the 2011.4.0 version released December 2011 and is considered stable enough for everyone to use. Most expensive DSLRs come with some minimal application that creates panoramas. Hugin does a lot more. Let us start off with a little about open source software.

Open source software is exactly that: you have access to the code that created the software so if you want to change it or fix a problem or even just see how it works, you can. Most people who work on open source projects do so as volunteers and from their homes. Because of this, the software isn’t always as polished or documented as much as a commercial package. But, the good news is that you don’t pay anything for the software. Worst case, you compile the software on your own, but are usually precompiled for most major operating systems. There are lots of packages that have been developed this way. Another popular project is the GIMP project – an 8-bit open source Photoshop clone. Let us get back to the review.

As I said before, Hugin is used to create panoramas by stitching images together. The images are stitched together with the software by overlapping the edges of images. There is an automatic mode that finds common points on its own or if you want to stitch it manually, that is always an option, too. The automatic mode is fairly easy to use if you follow the online tutorial. The manual mode is a lot more difficult and requires going through more tutorials (there are plenty of tutorials on using the application and plenty of documentation). Hugin will stitch the images, correct, blend, and export the panorama on its own. It will even crop and fix most problems that other panorama software out there today doesn’t. But, there is a lot more you can do by going through the manual mode. You can use the manual mode to average several images together and reduce the noise in an image. You can even use Hugin to create an HDR image. This is on top of everything you can do through the automatic mode.

One thing that needs to be noted is that most stitching software just aligns and blends the images together. Hugin does more. Hugin does vignetting, exposure, and white balance corrections, too. This helps to make the panorama less obvious that it was stitched and removes the lines that frequently occur when you stitch images together. Hugin also can make other types of panoramas like a stereoscopic and polar panoramas. It does quite a few other types of panoramas that I haven’t tried, but know it is fairly flexible in the types it does. Some examples of the types of panoramas you can make with Hugin can be found at this link.

As I noted above, this is open source software. It isn’t as polished. Because of this, you might have a program crash or get an error message that doesn’t make sense. If you do, try what you are doing again and it usually works without a problem the second time. If you are someone who gets frustrated with computers or has a difficult time following tutorials, this probably isn’t the software application for you yet. But, if you can tolerate a moderate amount of behavior issues with the computer where it doesn’t work exactly like it is supposed to work, then you should be able to use the package just fine with excellent results. In a few more releases, this application will be one of the better panorama and HDR software applications.

<img class=”alignright” title=”Mariah bokeh image” src=”http://galleries.xoind.com/photos/i-qLhPhZC/0/S/i-qLhPhZC-S.jpg&#8221; alt=”Mariah bokeh image” width=”200″ height=”300″ />Bokeh is a word that many photographers use. But, are they using it correctly? It is a word used to describe the quality of the blur you get from a specific lens. Some people pay a lot of money for a lens with good bokeh – but is it really noticeable?  To me, it is. Take for instance, the image at the right. The blur on the image is created only by the lens – none of it is photoshop. What do you think of it? I have a bigger copy of the same image on my <a title=”Link to Mariah bokeh image – her face” href=”http://www.flickr.com/photos/xoind/6894795999/in/photostream&#8221; target=”_blank”>Flickr</a>. If you look carefully, you can see the focus plane extends from the top of the model’s head to the bottom. But, that isn’t what we are interested. Instead, look at how the blur occurs over the skin closer and further away as it moves further out of focus. That blur is the bokeh.

The other type of bokeh is the type that talks about how bright light is rendered when it is out of focus. Most often, any lights that are out of focus render as spots based on the blades of the aperture. A few images are posted below. One of the interesting effects that you see with highlights or hot spots with mirror lenses is a “ring” effect bokeh (often referred to as a “doughnut” by those who own them).  An example of this can be found on Mike King’s Flickr page of a <a title=”Wind board surfer with doughnut highlights” href=”http://www.flickr.com/photos/mikekingphoto/5394380056/&#8221; target=”_blank”>wind board surfer</a> on the ocean. But, this isn’t the bokey we will be showing how to photograph in this blog entry.

Instead, we will be working with a regular lens type of bokeh and how it reproduces dots of light. There are two things we will be doing to ‘create’ a bokeh.

The first is taking and bluring the lights, most often Christmas lights (or similar types of point source lights), in the background. You will need a relatively large aperture lens – something with F2, F1.8, or larger. The easiest way to do this  method is creating a setup with the lights in a dark area behind your subject about 10-15 feet. I recommend doing this at night when it is dark out. The second is illuminating your subject from the sides (maybe a 45 degree angle from the front) so that you don’t light up where the Christmas lights are located. Key to this is keeping the aperture wide open at first, and then play with the aperture of the lens to get just the right amount of blur you want on the Christmas lights. Depending on the focal length and the distance to your subject, the amount of blur will be different. A note on cheaper lenses, the shape changes from a circle to a shape with the number of blades (typically five or seven) you have making up the aperture in your lens because the aperture isn’t perfectly round at the smaller sizes.  Some examples of this are below.

The second technique builds on this one by creating a mask of a specific shape to put on the front of your lens like a filter. By doing this, the shape of the lights then becomes that shape. Some of those are below.

All information and images are ©2012 Don Krajewski on this post.

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